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Some major upgrade advice

29K views 165 replies 10 participants last post by  Damocles 
#1 ·
I recently purchased a 2009 KLR650 used with the goal to rebuild it to suit my needs. I am a kidney transplant patient, so minimizing vibration is one of my goals. The other is to increase horsepower & torque. Hopefully, these are not mutually exclusive goals.

Let me take a few minutes to list what I had planned and perhaps you can tell me if you can improve upon my solution with a better plan. Please don’t suggest buying a KTM, BMW, etc. as I know I could do that and choose not to because they do not suit my needs. At a very basic level, I was the older 30 year technology with no excessive electronics and complicated technology. The current engine has 14000 miles on it. I have already ordered a full Cogent DDC kit for the front and the Moab Ultimate Pro rear shock. Should becready in another couple of weeks.

The motorcycle already has a 19” front wheel - I have a spare 21” & 17” already, progressive springs - I’ll be passing these on to someone after I replace them with the DDC kit, SS brake lines, dohicky replacement, Happy Trails, skid plate, engine guard, highway pegs, nerf bars, KLRDASH & Zero Gravity Sport Touring windshield I just finished installing, EM fork brace, lowered front fender, radiator guard, and theirs probably more. It was nicely farkles before I bought it.

So the rest of the plan is:

· Rebuild the engine using the Eagle Mike 719cc piston kit. https://eaglemike.com/719-forged-piston-kit-719pk.htm
· The above kit uses a custom cylinder liner. https://eaglemike.com/aftermarket-cylinder-liner-for-klr650-cylliner.htm
. Might use the Schnitz Racing 705cc Kit as it has reliefs for the oversize pistons. I’m not sure the EM kit has relief pockets for the oversize valves I plan to install.
· Balance the crankshaft, create a stroker rod, and install it. http://crankworks.com/
· Head port polishing and regrinding for the oversize valves and verification using their flow bench. https://www.racetech.com/
· M-Tech oversize valves. http://www.mtechmotorcycles.com/service/other-klr-big-bore-kits-etc/
· Viton valve seals. https://eaglemike.com/Viton-valve-stem-seals-for-your-klr650-engine-vvss.htm
· May need new valve guides.
· New intake & exhaust (163 grind kit) cams. http://www.webcamshafts.com/pages_vehicles/motorcycle/kawasaki/2525.html
· Web Cam spring & titanium retainer kit (VC-K07). http://www.webcamshafts.com/pages_vehicles/motorcycle/kawasaki/2525.html
· Manual chain tensioner. http://www.webcamshafts.com/pages_vehicles/motorcycle/kawasaki/2525.html
· Potentially replace consumable components (cam chain, cam sprockets, various seals, various bearings, etc.) as while I’m in there I might as well make sure I don’t have to go back in anytime soon.
· A fuel injection system to replace the current carburetor would be a significant plus factor. I have a line on a custom electronic ignition system that will allow me to modify the timing advance curve, but that’s about it. FI system are outside of my knowledgebase so don’t know where to turn for this issue. Lecturing carburation is also a possibility.
. A Thermobob 2 kit to improve the heating/cooling system.
 
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#2 ·
Ride it for awhile before you go into recreating a new bike... adventure! You might find that most of those changes are not needed.....just wanted! Farkle slowly is my advice, i have learned through the years riding a new bike for awhile changes your prospective of it.
 
#3 ·
Thanks, that’s good advice, but it’s an oil burner so one way or another it needs a new piston at a minimum.

I’ve also been riding on and off for over 40 years so have a good idea of what I want out if it as a street bike. The only real questionable options for me is stroking the engine out. I’m going to be splitting the cases to balance the crank anyway - I’m serious about minimizing vibration for my transplanted kidney - so a few hundred more into the build could add a good amount of torque and be worthwhile.

I’m just not sure if my list of parts is a good fit. I’m not familiar with all the brands. Or the KLR. it’s my first dual sport.

I’m in my late 50’s now and to go the places and do the things I want to do requires a dual sport. Mostly for fire roads, dirt roads, and occasional trails just to get there. Trails are probably about 1% though. I’m mostly talking about camping, fishing, or just taking in the view.
 
#4 ·
Let me take a few minutes to list what I had planned and perhaps you can tell me if you can improve upon my solution with a better plan.
Can't offer a better solution, although I can think of an alternative I think more likely achieving your design goals.

Won't suggest acquiring alternate bikes you mention, but . . . why not a Versys 650?

Reducing/eliminating vibrations on a single remains a hard row to hoe; the Versys as a twin naturally has the advantage. Plus, you get road manners the KLR never heard of; factory fuel-injection; more power than you'll likely get from your KLR hop-up, ABS, 6-speed transmission . . . I could go on! :)

Regarding, "balance the crankshaft;" ain't it balanced already? You mention, "stroker rods." What about the, "stroker crank" accompanying them? Custom build? Kit commercially available?

With reducing vibration as a priority goal, I question the choice of platform (single cylinder); even some of the mods (trick cams you mention lope a lot) seem to run counter to your design goal, my opinion only. Increasing torque doesn't reduce vibration, AFAIK, nor does a stroked engine.

About, "no excessive electronics and complicated technology;" your ambition for fuel injection; even the electronic adjustable timing you mention; seem contradictory, to me.

Regardless, your bike, your choices; best wishes toward modifying the KLR to fulfill your goals, if you must use that machine as your platform.
 
#5 · (Edited)
I am going to be as candid as I can, but no offense is intended.

One and all here will support the notion that I'll do wild, crazy, and questionable things to a KLR. I'll carry coals to Newcastle. Hell, I'll carry carbon dioxide to Newcastle, separate the carbon from the oxygen, and make my own damn coal right on the streets of Newcastle.

But I wouldn't do what you are proposing.

There just isn't that much potential for increased power or reduced vibration in the KLR motor.

To the level of purity of Ivory soap (“99 44/100% pure", they say), what you are looking for can be gotten by installing a 685 kit and a KLX needle.

The predecessor of the KLR650 was the KLR600. Kawasaki designed the balancer system specifically for the 600. When they built the 650 in '87 it required a heavier piston. They did not change the weights in the balancer system at that time, nor at any time right up to 2018, because it was 'good enough'. Any aftermarket piston is going to be lighter than the OEM piston and the balance will be better and the vibrations much less. I have a Wossner 678 piston in my bike and I swear that it vibrates less than my BMW flat twin.

The KLX needle and the appropriate (smaller) jet will solve the AFR issues and provide about as much more oomph as you're likely to get. Going beyond that is running into seriously diminishing returns.

If you are hard over on building a motor for the KLR I strongly suggest that you get ahold of KLRChris. He has built an injected KLR with revised cam timing and small-port heads. It was done at considerable expense and effort; he's made a career of dragging obscene horsepower out of cars and knows a thing or two. His is a better plan.

You did mention suspension mods and that is spot-on. Money destined for engine hop-ups would be better spent on suspension. The vibration, jolts, and shocks you are going to encounter off-road will be far greater than the vibrations you'll feel from a stock KLR engine. The KLR is poorly suspended and building good suspension for it will be far more beneficial. My KLR's suspension was built about 10 years ago; the damn thing floats over washboard and is exceptionally compliant in the rough. If you are going to be riding unpaved roads you're going to be riding over washboard surfaces. There are even better options today from Cogent than when I built mine.

Setting aside money for a decent seat from the likes of Corbin would be money well-spent, too. The stock KLR seat (at least prior to the '14.5 model) is an ass-hatchet.

The advice here is free and I suppose it is worth every penny you have given for it but, as William Mulholland so famously said, "There it is. Take it".
 
#6 ·
The Versys, well I considered it. Really, but don’t want it. Pretty much for the same reasons I don’t want a F800GS. Don’t want ABS, electronic suspension, or anything that must have a computer to work on it.

I know, FI kinda says otherwise, but in all honesty that’s not a requirement. More if a maybe as I hadn’t found another way to do much with the fuel air mapping or ignition advance curve. Plus RPM limiter. If I balance the crank assembly and use high performance valve springs with titanium retainers and keeps I know the RPM limiter will be way lower than is needed and I’d like to be able to use those extra RPMs. Maybe. It would need to be dyno tested and adjusted to know.

As for the whole stoker thing, that’s what Crank Works Inc. does. They provide a new rod, radius the corners so it fits with the current crank assembly, and lengthen the stroke. They can do this for just about any engine.

I’d have gone with EM 672cc stroker kit, but he told me it’s not available. So I can build my own if I want one.

As for vibrations, again I know it’s not the optimal platform. I just want to minimize what I can with the platform I’ve chosen. I know it’s not perfect, but I like the KLR. I just think I can modify it to be better for within certain boundaries limited by its design.

Yeah, I know it’s not cost effective. That’s not an issue for me. It’s not even an issue for me with my wife. And no matter what I do with the KLR it will be cheaper than a new $25,000 motorcycle. To be honest, I hate chains. I was going to buy a BMW 1200/1250 GS but didn’t want the weight thought about the F650/800/850 as I’ve driven them and owned many BMWs. Don’t want the complexity. Don’t want the weight. Don’t want the oh my god it fell over and now I have to ... worries/mentality.

I want a tank. Or maybe I should say VMW Bug. That platform has been around it seems like forever. Doesn’t do anything really well, but just keeps on going. And you can make it do anything you want with some money, some ingenuity, some labor, and sometimes some crazy tossed in there too. 🙂
 
#7 ·
Thanks for the post Tom crest assured I’m not taking any offense with your - or anyone else’s - reply. I’ve done quite a bit of research. Spoke to Mike too. He agrees with you and doesn’t think the changes I want to make are worth the money or effort either. I wish he didn’t feel that way as then I could get his assistance in rebuilding the engine, but that just doesn’t appear to be an option. So, if I want to get it done I’ll just have to do it myself.

Some people, myself included, follow the philosophy it’s not the destination, but the journey that matters. That’s where I am now. Mapping out my plan to get what I can out of the engine. Mike had a stroker in the works and from what I’ve read it produced additional power & torque so I know it’s possible. Been on other stroked out thumpers so I know it works.

I know that larger valves on a cc upgrade can also be beneficial. Not sure if the cams I’m looking at will match up to an appropriate power/torque curve though. That’s part of why I am looking for FI or after market EDI/CDI or different carburetor too.

And I forgot to mention I already have the KLX needle upgrade and resetting of the stock carburetor. It’s going to be too small though if I upgrade the cc to a 700+ piston and/or stroke it too.

I’m also looking at another seat. Not from Corbin though as theirs is too rigid for me. I bought a used seat pan to be modified. Just haven’t decided who’s going to build it. I want it a bit narrower up front so I can get better foot placement, soft enough for commuting, but still rigid enough for some off road riding. Don’t want a premise seat though. I want a custom one. Got a couple of ideas on who’s going to make it, but nothing pinned down yet. I’ll probably wind up with a drive in service to get it just right. I should also note, it will need dual heating pads. That and heated grips are two items I really do miss from my BMWs.

FWIW if I can get 10-20 more usable horsepower out of the engine I’ll be very happy with that alone. The KLR - as it stands today - is just too underpowered for my highway driving style. I’m in southern CA and we cruise at 80 on the highway. I usually drive a few mph faster than surrounding traffic so I’m visible as a moving object rather than stationary and therefore attract the human eye rather than be invisible. Plus, that extra power will come in handy when fully loaded.

I compared the KLR to a Volkswagen Beetle, but don’t want to be crawling up hills in traffic. So I need more from the motor than it is stock. And I don’t see a reason to ever put in a smaller piston than is possible unless I’m after a high rev engine. I don’t think the KLR is suited for that, so larger pistons with an increased stroke and maybe - just maybe - an extra 1000 RPMs is doable safely.

And yes, I could be a nut job. Just comes with the territory. I will see if KLRChris has any suggestions, but NOS is not going to happen on my ride. That’s one step too far even for me. 🙂
 
#9 · (Edited)
FWIW if I can get 10-20 more usable horsepower out of the engine I’ll be very happy with that alone.
You're talking an extra 25%-50% of rear wheel horsepower. Easier said than done, IMHO.

Further . . . none of the modifications you propose address significantly the VIBRATION issue you mention, as far as I know. I'd think some of the modifications, like stroking, might INCREASE vibration; certainly, trick cams will.

As Tom mentioned, the counterbalancer system was not changed between the KLR600 and KLR650 models, although the change in mass and geometry might suggest it should have been. Stroking? The center-of-mass location and magnitude of the rotating weights might want some sophisticated adjustment, given the change in dynamics consequent to stroking.

A supercharger or turbocharger might satisfy your increased power ambitions.

Regardless, please keep us advised on your hop-up progress; ideally, with before-and-after dyno runs and/or quarter-mile drag strip timing slips.

Again, best wishes, good luck!
 
#8 ·
Nah, no crazy involved. A reliable bike tricked up because the journey is as much fun as the destination.

I'll quote the OP (some of it out of context but it fits IMO):
'The KLR platform "has been around it seems like forever. Doesn’t do anything really well, but just keeps on going."'
"Don’t want ABS, electronic suspension, or anything that must have a computer to work on it."
"Don’t want the complexity. Don’t want the weight. Don’t want the oh my god it fell over and now I have to ..."
"...older 30 year technology with no excessive electronics and complicated technology."
"I’m mostly talking about camping, fishing, or just taking in the view. "

The KLR sounds ideal. It isn't a horsepower monster and never will be but that can be increased, it is heavy for its size but it is possible to lift it up again, all the bugs are known so can be easily fixed, it handles like a dead fish in stock configuration but that can be fixed, etc. Plus it is really great to ride.

It does vibrate a lot but I have found that it doesn't affect the rider as much as it just works all the bolts loose with amazing regularity.

IMO the new-fangled CDI ignition stuff is a bit whizz-bang high-tech but I bought the bike anyway, so I guess I'm just an early-adopter!:laugh3:

Great choice, let us know how it goes.
 
#10 ·
IMO the new-fangled CDI ignition stuff is a bit whizz-bang high-tech but I bought the bike anyway, so I guess I'm just an early-adopter!:laugh3:
A minor detail, 89a3: Generation 2 KLR650s (2008 and later models) have no CDI (capacitive discharge ignitions); rather, the latter-day bikes have what Kawasaki once called, "Fully-Transistorized Breakerless Ignition," a great leap backward, IMHO, to an inductive discharge ignition system.

Although Kawasaki marketing literature may claim, "electric CDI," in specification sheets, they ain't got no stinkin' CDI! :)
 
#11 ·
Well, I'm late to the conversation. I'll add:

- your suspension mods are money well spent IMO, although the Pro-Series is a bit overkill (I have one too. ;-) )

- I was going to suggest just talking to Mike and dealing with one vendor rather than 3-4 on your engine mods, but it appears you've spoken to him already. The BB kit will lessen vibes, I have no idea on the stroker except to say you're now treading down a path that VERY few people have taken. .....your 10-20hp goal is well within range without the stroker kit (or a supercharger, LOL) using the BB kit, cams, porting, etc. along with supporting intake, exhaust mods https://www.klrchris.com/60-hp-fuel-injected-klr-650/ . Personally, if I was building a KLR with little concern about budget, I'd do the 719, ported head, bigger valves, intake mods and your silencer of choice and leave it at that - more or less a tried and true solution that should get you 10+hp....but to each their own.

Cheers,
Dave

On edit; I see Tom already gave you Chris' link.
 
#12 ·
I'll offer a couple of suggestions,

[Quote, "Let me take a few minutes to list what I had planned and perhaps you can tell me if you can improve upon my solution with a better plan. Please don’t suggest buying a KTM, BMW, etc. as I know I could do that and choose not to because they do not suit my needs. At a very basic level, I was the older 30 year technology with no excessive electronics and complicated technology. The current engine has 14000 miles on it. I have already ordered a full Cogent DDC kit for the front and the Moab Ultimate Pro rear shock. Should becready in another couple of weeks."]

The best suspension available still needs a freshly inspected and thoroughly greased set of suspension & steering pivots. The lower suspension rocker arm bolt is prone to rusting into the frame. But I wouldn't install grease zerks into those 2 stupid holes. :)
https://www.souperdoo.com/stuff tha...-come-out-or-two-very-important-zerk-fittings

[Quote, "And I forgot to mention I already have the KLX needle upgrade and resetting of the stock carburetor. It’s going to be too small though if I upgrade the cc to a 700+ piston and/or stroke it too."]

You really need to read All of klrchris' performance upgrades. The Keihin CVK40 carb is actually quite good in his opinion. The problem is multifaceted.
His 685cc carburated engine with his porting seems to be quite effective. No real need to add a stroker crank which would add vibes.
https://www.klrchris.com/
 
#14 ·
You really need to read All of klrchris' performance upgrades. The Keihin CVK40 carb is actually quite good in his opinion. The problem is multifaceted.
His 685cc carburated engine with his porting seems to be quite effective. No real need to add a stroker crank which would add vibes.
https://www.klrchris.com/
KLRChris claims 20 % more power from stock with, "First stage mods consisting of KLX needle, 142 main jet, air box mod with 2/3 door removed, FMF Power Bomb and PowerCore4."

Given this dramatic increase in power from relatively minor mods, the 10-20 additional horsepower 89a3 desires appear more easily attainable than I thought.
 
#13 ·
FWIW, I’ve read KLRChris mods on his web site many times. It’s actually wear I started with the upgrade concept. I just hadn’t looked at the link to make the association previously. I’ve also looked at some of his other postings here and there about owning the fastest KLR650 on the planet. I’m not looking to do that. No NOS. No records. He’s already hit 60 hp so, I know getting 10-20 hp more is doable. Where I’ll wind up on the scale though I won’t know until I’m done.

I’ve looked at the 719cc piston on Mike’s web site. It doesn’t look like it has relief pockets for oversize valves. So, I’m not sure that will work for me or not with the higher lift/duration cams. I’ll have to call and ask him and see if he can tell me

Pdwestern - Pat - I’ve read all the info on the web site. And followed up with a lot of your historic postings. I’ll have to think about the zero fittings. I have considered a bearing upgrade/replacement since I’ll have the back end off anyway. It will get lubed at a minimum before my new shock goes on.

And I have to ask ... do you still think the oil mod is a good idea? Good idea for the modified engine I’m suggesting? I purchased the three bolts with larger diameter holes but haven’t used them yet.

Dave, well I have to say the only reason ... and I mean only reason ... I bought the Moab Ultimate Pro was because it has adjustable compression damping. In fact, any shock I could find with compression adjustability was over $1300. I checked with everyone I could find. I really wanted a Touratech with adjustable high and low speed compression but they didn’t offer one and didn’t have a body that would fit the KLR with those options. I know it’s more shock than I’ll ever use to it’s extremes, but it’s adjustability is what I needed to soften up the ride.

As for the vibrations issue Damacles brought up again, I’m never going to get rid of all the vibration. I know that. And I know some things I’ve proposed might make it worse. Then again, I’m trusting Crank Works Inc to minimize the vibrations. You do realize I hope that balancing a crankshaft, rod, and piston assembly means removing or adding weight? It doesn’t matter what the stock setup is or what it was made for. I’m aware the engine was balanced for a 600cc piston, but again that doesn’t matter since Crank Works Inc is going the balance the entire assembly.

If I can follow my plan and build out the engine as described, I think my biggest issue will be air flow - carburetor & exhaust - tuning. Air fuel ratio might also be an issue.

Just curious but has anyone used the Ecotrans EFI Kit? http://www.ecotrons.com/news/suzuki-dr650-dual-sport-fuel-injected-with-the-ecotrons-efi-kit/ It’s used by some for the DR650. So, yeah, I’ve been wondering about it too.
 
#15 ·
Dave, well I have to say the only reason ... and I mean only reason ... I bought the Moab Ultimate Pro was because it has adjustable compression damping. In fact, any shock I could find with compression adjustability was over $1300. I checked with everyone I could find. I really wanted a Touratech with adjustable high and low speed compression but they didn’t offer one and didn’t have a body that would fit the KLR with those options. I know it’s more shock than I’ll ever use to it’s extremes, but it’s adjustability is what I needed to soften up the ride.
Don't get me wrong, I believe the Ultimate Pro-Series is the best shock for the KLR that money can buy - I love mine......it's just a bit overkill for the rest of the bike but I have a (perhaps unhealthy!) strong interest in KLR suspension mods so I had to have the "best of the best" to compare. There is zero downside other than cost.


Cheers,
Dave
 
#18 ·
ILove2Ride2Wheels,
The reason that I would NOT use grease zerks on those 2 Stoopid Holes in the lower cross-pipe is so as to Not Ever Fill the bottom 8 vertical inches of the main frame with grease & have it melting out on hot days, like Tom Schmitz aka Souperdoo eventually discovered. The pipes are apparently vented to each other before welding.
Two simple 5mm phillips screws or even RTV is sufficient to keep the water Out.

Yes I'll suggest a #43 / 2.26mm / .089" crankshaft oil control orifice in the 6:00 oil port of the oil filter cap along with the KLX, KLF oil pipe banjo bolts in the oil pipe.
klrchris even mentioned using this mod on his engine. :)

(Heck, klrchris might have even used the 100% oil filtration on his engine. I'm uncertain on this.)
 
#19 ·
From my drag racing days; "internal balancing" is a term we used when the piston and rod weight was offset by the crankshaft counterweights (by drilling or adding "mallory metal), "externally balanced" is if you needed to add an external weighted damper (like a crankshaft damper/balancer). Internally balanced is/was always better if you can acheive it. On my 440-6 race engine, it was externally balanced from the factory due to the very heavy pistons and rods being too much for the crank counterbalancers to deal with but I was able to eliminate the external damper and have the reciprocating assy internally balanced by using lighter than stock rods and pistons.

In the KLR, we use what would be considered an "external balancing system" even though it is "inside" the motor. As Tom mentioned, the KLR650 counterbalance weights seem to have been designed for the lighter KLR600 piston so it isn't functioning 100% in the stock configuration. The use of an aftermarket piston that is lighter (like Eaglemike's pistons) helps by more closely matching the counterbalance weight.

If you were going to do up a KLR650 stroker, it would be advantageous to have the new/modded crank, rods and pistons balanced to match the external balancer weights to reduce vibes as much as possible - especially if you were going to raise the redline a bit. ....would take some work to do it right.

Dave
 
#20 ·
ILove2Ride,
I am 99% certain that all of Eagle Mikes JE brand oversized pistons are probably relieved for up to 1mm oversized valves and higher lift cams, but still best to confirm with him. I can see valve reliefs in the pic, just not sure of the size.

https://www.eaglemike.com/719-forged-piston-kit-719pk.htm
 
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#21 ·
The KLR vibrates at a lower frequency than twins or fours even BMW twins. I have found in many decades of riding this big thumper is less bothersome than any of the twins or fours i have owned in the past, that is why i mentioned ride it for a few miles before major mods! From what everyone who has done the 685-719 piston change has said the felt vibration is less. A proper dohickey will cure a lot of vibration problems as well. Different bars and/or different bar end weights can change the frequency or RPM range of felt vibration also.

Seat concepts or others will cure the monkey butt seat problems!

Read the Cam Advance MC Mod thread its free and easy torque.

Just being in the wind cures many perceived faults or they seem less important, for old guys time is short enjoy as much wind time as you can!
 
#22 ·
Thanks for the reply. I’ve read the thread on the MC mod already. It was an interesting read.

I’m still researching away, but found some interesting threads on the setup I am looking at doing, but didn’t find the results yet. So still searching for more information.

One thing I did find is a 705cc kit with the web cams 163 grind and oversize valves can push the engine to close to 60hp. But the pics for the torque curve expired so could see where the powerband was. One basic concept was hp was increased along the entire powerband when compared to stock. So I might get what I want out of the upgrade.


Sent from my iPhone using Tapatalk
 
#23 ·
go wild and pull the airbox and put a lectron carb on it. throttle response is quite crisp. i also dumped fatass lead acid battery and put a 3 lb lithium ion battery. go all out if ya have the cash
cannot even see the battery and look at all the air. now ya see see that cogent shock too!




used a roof of a plastic battery box as a tray. used a piece of thin flat stock as a platform



 
#24 ·
The Lectron carb is on my short list. I’ll be considering it, a pumper carb, and a FI carb. Not sure which way I’m going to go. A lot depends on what I can find and what mods are required to make it fully functional.

I like the idea of a LiFe battery, but could never do what you did. I’d be afraid the first big bump would pop the cable ties and dump the battery.

I’m also not sure about getting rid of the air box. Sounds great for the street but not sure about using it in the dirt. Granted, I won’t be spending much time there but do want have the option.

And FWIW, you have a really nice looking ride. For a street bike it’s very aggressive, but I’m afraid mine is going the route of a pack horse. I want to use it for camping/fishing trips so it’s going to be burdened with side cases. I already have a top case on it.


Sent from my iPhone using Tapatalk
 
#26 ·
The Lectron carb is on my short list. I’ll be considering it, a pumper carb, and a FI carb. Not sure which way I’m going to go. A lot depends on what I can find and what mods are required to make it fully functional.
Your bike, IL2, but . . . none of these mods contributes significantly to your stated objectives, increased power and reduced vibration, IMHO. Seems to me, an optimum air/fuel ratio, whether from a CVK40, Lectron, pumper, or even fuel injection increases power. If I'm in error, I'd like to know the mechanism producing additional power from the same combustible mixture.

Nevertheless, your planned project appears most interesting; looking forward to images documenting your progress, particularly of the stroked crankshaft and shortened connecting rod.
 
#27 ·
Well the stroked crankshaft is now history after another chat with Mike. Unless I can find a builder to help me figure out the piston issue.

While talking with Mike he mentioned Crank Works Inc. did the original modifications for his kit. So I talked to him and asked a bit more about the process. CWI will build be a longer rod. They will relocate the crankshaft pin. But ... they didn’t provide any info on the piston and my research - talk with Mike confirmed it - that to build a stroker requires a piston with the wrist pin located more toward the piston face. I don’t have one. Mike has a couple of beta pistons but those are for his future projects and I couldn’t buy one. So I need a builder that can help me with that part or just pass on it.

With my current time line - start disassembly ASAP or at a minimum by Thanksgiving and ship out the parts for the machine work and pray I get it all back for a Christmas reassembly - that’s a problem. It’s $425 just to true & balance the crankshaft. Plus another two to three hundred in tools for the job. And I forgot new seals. Not sure how much it would cost for all of them, but figure another one to two hundred. So unless I can get some quick results I’ll save the $700-$900 and see how much less the vibration is with just the 719cc BBK.

I’m still going with the fully ported head by RaceTech. With 1mm oversize Schnitz Racing SS valves, new valve guides, WebCams 163 grind cams and high performance valve springs, the total is somewhere close to $1500. The head should flow much better than stock. RaceTech will provide flow bench results of the before and after results and I’ll post those when I get them.

In any case, more flow equals more power along the entire powerband. I’ll need a way to provide more fuel/air at the right ratio to realize that power. Flow in also requires flow our. So I’ll need improved header & muffler too. If I can get it all right, then the engine should be pushing close to 60 hp. I’m not the first to do this, so know it can be done. I’m just trying to do it with more off the shelf parts.

FWIW, if after I get this all together and still need to lower the vibrations more, I’ll still pull the bottom end and send it out for balancing with the 718cc piston. I know it’ll never be vibration free. That’s impossible with a single cylinder engine, but balancing the assembly can minimize the vibrations.


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#28 · (Edited)
CWI will build be a longer rod.
Since the crankshaft stroke is longer (greater) with a "stroker" modification, I thought the complementing rod would be shorter, not longer. My mistake!

:)

-------------------------------

Just a thought; as to reducing engine vibration, have you considered fabricating and installing a heavier flywheel/rotor? The increased mass, and possibly, consequent shifted center/moment of inertia, of such a replacement flywheel should definitely reduce engine vibration. Such a mod would also enhance continuity of power/torque delivery at low rpm, as when you ride your KLR off-road (less tendency to stall).
 
#29 ·
I had not considered adding mass as primarily means to lower vibration unless needed to balance out the reciprocating mass (piston & rod assembly). Otherwise, I’d just be creating more vibration rather than less - most likely.

It’s difficult to tell as they don’t balance out counter balancers in general although they do for a Honda 250. Truthfully, I’d spend the money to balance out every reciprocating hunk if metal in the engine if I could. Sure, it costs money, but my donated kidney means a lot mitre to me then the small amounts I’m putting into the engine. I’m not going to give up motorcycles though. Not until I’m physically incapable of riding.


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#31 ·
I had not considered adding mass as primarily means to lower vibration unless needed to balance out the reciprocating mass (piston & rod assembly). Otherwise, I’d just be creating more vibration rather than less - most likely.
Hardly, IMHO. Take a look at massive industrial engines, with their humongous flywheels.

Yet, your bike. Still anticipating a longer rod with your stroker kit?

:)
 
#42 ·
Yes, but generally speaking when creating a stricter engine the pin on the crankshaft is relocated. Outward for a longer rod. Inward toward for a shorter rod. The piston wrist pin is higher than a standard location for a longer rod and for a shorter rod the wrist pin is located lower.

Generally speaking, this means a short stroker uses talker pistons to maintain the same or larger displacement. The opposite is true - generally - for longer rod stroker engines.

I’m not making this stuff up. I think the last link posted spelled out some of this information. I e found other references to it too, but most of it is applied to cars rather than motorcycles and so the lines get blurred. From what I’ve found, motorcycles - in general - have a more pronounced visible change in rod/piston size for a stroker engine.

Hmm, that gives me an idea. I should check with Wiesco - I think that’s their name - about a piston for the KLR stroker project. I’ve used their products in the past and should of thought of them sooner. Maybe they can provide some insight or a kit (doubtful).


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#43 ·
ILove2Ride2Wheels,
To the best of my knowledge, most stroker kits use the stock piston pin position and a slightly shorter rod. The Powroll company used the simply heat the rod and compress it by half of the intended added stroke. (Created a bulge in the rod.) Then the oem size bottom crank pin was/is relocated an equal amount towards the OD of the crank flyweights.
This keeps the piston crown deck height in the cylinder the same as oem, but pulls the piston further down the cylinder bore at BDC.

There is only 1mm of material between the piston pin bore and the bottom oil rail of an Gen 2 OEM KLR650 piston and probably the EM JE brand and Wossner brand pistons also. No room to move the pin upwards.

https://www.openfos.com/supply/3194880-POWROLL-MOTOR-PERFORMANCE-in-CROOKED-RIVER-OR/
 
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#45 ·
In my youth, I remember when folks would stroke their HD Panhead and Shovelhead engines by moving the crank pin slightly further away from center. Then, to keep the piston from bashing into the head, they would install a "stroker plate" between the cylinder base and the engine cases.

Jason
 
#44 ·
That’s an interesting technique and now that you’ve mentioned I recall seeing a pic of something like that in my younger days. I’m in my late 50s. I think now days, the cut and weld, but I was looking to have a rod made. They only cost about $300 or so.

I checked the Wiesco web site. They don’t offer anything but an OEM replacement. I’d hoped they’d offer custom services as I know an OEM piston isn’t going to work.

I appreciate the information though. Maybe I’ll see if my Google skills can find a custom piston shop before I just give up and settle for the 719cc BBK. Although, my wife would be happier if I didn’t do the bottom end just because of the additional cost. :) the rest was already budgeted in to my purchase - new with minor farkles or used with complete engine rebuild. Either would get new shocks so those didn’t count. But the bottom end changes would put me over budget on the purchase.


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#49 ·
I don’t think so, but possibly. I’d have to see the measurements and compare them to stock to know for sure.

There’s no reason for me to do it that way though if the displacement doesn’t increase as well. The whole point of a stocker IMO is to increase displacement, increase torque, and increase horse power.

I was running some calculations and just a 6mm longer stroked increased the CCs significantly. A stick is 651.88cc. Up the stroke 6mm and it’s up to 699.01. Use a 105mm piston (aka EM) and it’s 770cc. I’m not sure what piston size Mike was using for his 762cc stroker, but it might be close to what I’ve posted.

Honestly, I don’t know how much room there is to relocate the crankshaft pin. It has to be done in such a way that it does not hit the cylinder skirt and still have a relatively shallow enough angle to push/pull the piston without too much resistance. Plus, you need to keep in mind to maximize the displacement increase the wrist pin needs to be closer to the piston dome. Usually this means a thinner piston. Sometimes with only two rings instead of three. It can be complicated.

I really wish Mike had a spare piston he’d sell me. Or would do the work for me for a stroker kit. I’d drop of my motorcycle in a heartbeat if he would. It’s his & Sam’s project though and I can respect his choices for it.

One thing I’m sure of ... whatever I wind up with will perform better than stock. Plus, I’ll still have to finish up the build with carburation, exhaust, and possible FI mapping or customized CDI - I know that’s not what it is, but what else should I call it - unit. If I could only get that Czechoslovakia company that makes them respond to my email I might be able to get a programmable CDI unit.


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