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Discussion Starter #1 (Edited)
I stumbled across this mod( advance exhaust cam 1 tooth) and wondered why there is not more discussion on it. I had some valve noise on my 2009 with just over 7000 miles so I checked clearances and they were all tight. Intake is .004 both, Exhaust is .006,.005. I am waiting for shims. Anyways with the possible gains from advancing exhaust cam, why isn't this a more popular mod? Any and all opinions welcome. OK There is plenty of discussion about this mod here on the forum, just none lately. I'm still new to this (5 months) apologies for my ignorance
 

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Merit in the, "MC," mod, IMHO, requires a leap of faith.

Some pre-2008 owners report no gain; some post-2008 owners report power increases at different rpm (seat-of-the-pants dynamometers).

Your bike; mod it the way you like.

BTW, ever hear of the, "PCV VALVE" modificagtion? Some claim many diverse advantages from this procedure, including increased power. :)
 

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Discussion Starter #3
Thanks for the response "D".I have heard of the pcv mod, advancing the cam costs nothing since I was in there. I still may try it though. As you have stated gains are relative . "Build it and they will come"
 

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There are tons of threads on the subject but unfortunately many search engines have problems with two or three character words .....like MC for eg!

My 2 cents; On a Gen2, I'd probably try it......potentially you gain a little mid range tapering off at the top. perhaps a bit less engine braking too which you may like....or not. Results vary; from EM " The camshaft drive sprocket on the crankshaft varies in timing" from bike to bike.

On a Gen1, I've heard mixed results - enough so that I haven't bothered trying and don't intend to.....after all, we're talking maybe 1hp (less at peak)




If you really want to get into trying to maximize the KLR's performance (a bit of an oxymoron) these guys make adjustable cam gears and scoff at the MC mod; https://www.klrchris.com/klr650-adjustable-cam-gear/


My thoughts are that I trust Eaglemike; he knows his stuff. Since the MC mod is free, I'd try it on a Gen2. Gen1's have a different exhaust cam and don't seem to get the same benefit. Results seem to vary between bikes probably because of slight tolerance differences between factory timing. I wouldn't bother with expensive adjustable timing gears because I think the "bang for the buck" is on the low end of the scale.......spend the money on suspension mods where you really can make a difference. Lastly, forget the PCV mod! ;-)


Cheers,
Dave
 

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I stumbled across this mod( advance exhaust cam 1 tooth) and wondered why there is not more discussion on it. I had some valve noise on my 2009 with just over 7000 miles so I checked clearances and they were all tight. Intake is .004 both, Exhaust is .006,.005. I am waiting for shims. Anyways with the possible gains from advancing exhaust cam, why isn't this a more popular mod? Any and all opinions welcome. OK There is plenty of discussion about this mod here on the forum, just none lately. I'm still new to this (5 months) apologies for my ignorance
The MC Mod is 'free to try & free to reverse' if one already owns a 40-200 INCH Pound Torque wrench. Like my 4 basic PDW Oil Flow Mods, totally reversible.

The KLRChris adjustable cam sprockets can apparently make quite a difference or just some improvement, which all depends on how close to original blueprint your entire engine is to spec (Probably Not Very Close).

But one needs a couple more specialized tools and the knowledge & patience to use them. The KLRChris adjustable sprockets (after core exchange) are less expensive the Soupys Adjustable Suspension Links. So price of the parts should only be of minor consideration IMHO for those truly interested.

Read this thread,
https://www.klrforum.com/2008-klr650-wrenching-mod-questions/66449-cam-timing.html

Read this 5 part Cam timing website, by our own Tom Schmitz aka Souperdoo.
https://www.souperdoo.com/stuff that i think about/the-perfect-timing-cams-that-is

You've already got the link to KLRChris.

And do not waste your time and a destroy a perfectly good crankcase vent hose with an in-operable at riding speed pcv valve!

Just my honest opinions.
 

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Yep, it's hard to argue with the cost of the MC mod. To clarify; for ME the $235 plus shipping, duty, time and tools for the adjustable cam gears is more than I'm willing to invest to chase a potential hp or two.....others can and will have different priorities and there is nothing wrong with that.


Dave
 

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Discussion Starter #9
Starting to realize my 2009 with 7000 + miles is burning approximately a quart per 1000 miles, approx. 70% of that highway 5000 + rpms. Nothing to be alarmed about is it? I am starting to consider 685 kit to stop oil consumption, if that is a remedy
 

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Yep, it's hard to argue with the cost of the MC mod. To clarify; for ME the $235 plus shipping, duty, time and tools for the adjustable cam gears is more than I'm willing to invest to chase a potential hp or two.....others can and will have different priorities and there is nothing wrong with that.

Dave
I heard about the miraculous free MC mod and advanced the exhaust cam one tooth when I had the cam cover open. Couldn't tell any difference so I moved it back the next time I had the cover off. Still couldn't tell any difference. If I don't notice it, it's not worth it.

KLRchris does offer a right side stand which has come in handy for me on several occasions. Mostly when i pull off on a right side shoulder sloping to the right and the left side stand tries to push the bike over to the right.
 

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Starting to realize my 2009 with 7000 + miles is burning approximately a quart per 1000 miles, approx. 70% of that highway 5000 + rpms. Nothing to be alarmed about is it? I am starting to consider 685 kit to stop oil consumption, if that is a remedy
My ‘16 with 8,000 miles burns one in maybe 1500 miles when riden 5k+ rpm. I wouldn’t be too concerned yet on yours, unless you’re like me and just want to do it.
Have you installed a larger front sprocket? If I remember correctly a 17 tooth will fit. Someone correct me if not.
 

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And do not waste your time and a destroy a perfectly good crankcase vent hose with an in-operable at riding speed pcv valve!

Just my honest opinions.
Don't listen to pdwestman, beamwalker! He's just an old meanie, who wants to deny you the advantages of the PCV Valve Mod (more power, better fuel efficiency, enhanced ring seating, lower oil consumption, and . . . a half-dozen or so more I can't remember)!

I jest. Harken to pdwestman. I merely point out; sometimes, something that sounds too good to be true, IS, really, too good to be true! :)

Concur with previous posts; MC Mod remains free, and, reversible. Name your own hop-up poison!
 

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Starting to realize my 2009 with 7000 + miles is burning approximately a quart per 1000 miles, approx. 70% of that highway 5000 + rpms. Nothing to be alarmed about is it? I am starting to consider 685 kit to stop oil consumption, if that is a remedy
When my 2008 started burning oil in warranty I asked the Kawasaki dealership where I bought it how bad it was. They said at a quart per 1,000 miles it was eligible for warranty repair. At a 20,000 miles and a quart in 800 miles they honed and re ringed it in warranty. At 40,000 miles it was back to a quart in 1,000 miles so I installed a 685 piston. No more oil burning at 100,000 miles.
 

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Discussion Starter #14
Don't listen to pdwestman, beamwalker! He's just an old meanie, who wants to deny you the advantages of the PCV Valve Mod (more power, better fuel efficiency, enhanced ring seating, lower oil consumption, and . . . a half-dozen or so more I can't remember)!

I jest. Harken to pdwestman. I merely point out; sometimes, something that sounds too good to be true, IS, really, too good to be true! :)

Concur with previous posts; MC Mod remains free, and, reversible. Name your own hop-up poison!
Have you done either mod Damocles? What were your results
 

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Thanks for that info Gomotor. With the 685 , what is your speed at say 5000 rpms?
The oil info above is for a 2008 as noted. I still have it, but am now ridding a 2011. It now has 60,000 miles with no unusual oil burning.

The speed at 5,000 rpm is the same for both bikes with either piston size unless you change the sprocket ratios.

My speedometer is a computer on the right handle bar. Looking back and forth between the speedo, the tach and the road ahead, it is a little difficult to get 100% accuracy. My speed with stock sprocket gearing is about 65 to 67 mph at 5,000 rpm.
 

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Have you done either mod [MC or PCV Valve) Damocles? What were your results
MC Mod? No.

Why not? MC Mod loses 15 crankshaft degrees of valve overlap. My belief system holds: Valve overlap enhances higher rpm performance. Thus, my rationale: Why sacrifice valve overlap? BTW, my bike is a Generation 1, whose owners implementing the MC Mod report extremely mixed reviews (see GoMotor's post detailing his experience on this thread).

PCV Valve Mod? No.

Why not? TRUE BELIEVERS in the claimed myriad advantages of the PCV Valve Mod were awfully vague in describing the actual operational principles of its function. More-or-less, a consensus among this group maintained the PCV Valve Mod created a VACUUM in the crankcase; said vacuum somehow delivering wonders to behold.

In actual testing, no vacuum was ever measured in the sump; rather, an over-pressure was indicated under all operating conditions except extreme deceleration. Thus, with only a mystical inference postulating a crankcase vacuum produced the alleged benefits, and the actual non-existence of such a vacuum, I harbored doubts regarding alleged benefits of the device.

Further, some who implemented the PCV Valve Mod reported a consequent oily mess.

And, BTW: Merely installing a check-valve in the crankcase vent line does not a PCV (Positive Crankcase Ventilation) system make.

These skeptical comments aside; by all means modify your bike as you see fit. YOU are the only one to please with your bike's configuration! YOU decide whether the expected gain from a modification justifies the effort required implementing the mod.
 

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Starting to realize my 2009 with 7000 + miles is burning approximately a quart per 1000 miles, approx. 70% of that highway 5000 + rpms. Nothing to be alarmed about is it? I am starting to consider 685 kit to stop oil consumption, if that is a remedy
Beamwalker, Keep your engine oil level in the top 1/4 of the oil window.

Do you own a drill motor? I developed and tested a modification to help reduce high RPM oil consumption.

#1, Reduce the amount of oil coming thru the crankshaft rod pin roller bearing & therefore onto the cylinder wall & overwhelming the rings. Look at the brass orifice in the 2nd picture and ignore the epoxy and other pics at this time.

https://www.klrforum.com/386418-post418.html

The amount of oil burn reduction can not readily be estimated, too many variables. There are 3 more simple steps to the 4 Basic Primary modifications of the PDW oil flow mods. These are the Banjo Bolts in the oil pipe to the camshafts & transmission shafts.
 

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Beamwalker, Keep your engine oil level in the top 1/4 of the oil window.

Do you own a drill motor? I developed and tested a modification to help reduce high RPM oil consumption.

#1, Reduce the amount of oil coming thru the crankshaft rod pin roller bearing & therefore onto the cylinder wall & overwhelming the rings. Look at the brass orifice in the 2nd picture and ignore the epoxy and other pics at this time.

https://www.klrforum.com/386418-post418.html

The amount of oil burn reduction can not readily be estimated, too many variables. There are 3 more simple steps to the 4 Basic Primary modifications of the PDW oil flow mods. These are the Banjo Bolts in the oil pipe to the camshafts & transmission shafts.
Thanks, seems like a big job. I read about it a little. I'm not far from Tom maybe I can get him to help me out, as he did with the doo and exhaust. He is a good dude. Does the 685 kit eliminate oil burning or only reduce it? I appreciate it man
 

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Thanks, seems like a big job. I read about it a little. I'm not far from Tom maybe I can get him to help me out, as he did with the doo and exhaust. He is a good dude. Does the 685 kit eliminate oil burning or only reduce it? I appreciate it man
Oversimplification but there is basically two ways a KLR burns oil;

- 1) High rpm oil burn - caused by the issues that Paul lays out in the information he posted. The mods he makes have proven to be effective in reducing oil consumption in this instance. Most thumpers will burn some oil in these circumstances. sustained highway rpms over 5000 typically cause some consumption. lowering the rpms by changing the drive ratio (usually using a larger countershaft sprocket) can help mitigate.

- 2) Oil burning due to poor oil control - this is due to poor ring sealing due to the ring design in some cases and bore distortion. This can cause extreme oil burning. The 685 kit is the fix for this.



A related post I made on the subject a while back;
Honestly I think the bore has a propensity to go out of round on the bottom end regardless......but the T bob may lessen the distortion to the extent that the rings can compensate. Cary theorized that after a number of heat cycles the bore tends to become relatively static - which is why it stays fairly stable after a 685 rebore job. The '08's and '09's have a well deserved reputation for oil burning due to the ring (re)design, not because the bores are way worse than earlier or later bikes.....this is based on my review of some of KLRCary's material as well as my discussions with Eaglemike. Cary described the bore distortion as a design issue. Mike's belief is that if you put an earlier or later piston/ring set into a virgin 2008 or 2009 bore that it would have no greater chance of being an oil burner than other years.

To recap my thoughts;

- early Gen2's ring design was poor leading to a much higher incidence of oil consumption; as the bores distorted the rings couldn't control the oil.
- KLR650's have a propensity for some degree of bore distortion due to the design (lack of support on the bottom end of the sleeve and the thickness of the sleeve)
- the bore shape tends to stay relatively static after a certain number of heat cycles which is why the 685 kits usually solve oil consumption issues (and Mike's rings seal better)
- Aftermarket sleeves such as the 705 sleeve are beefier and don't distort much, if at all.
- the Thermobob helps lessen bore distortion by greatly reducing the delta T of entering and leaving water (cold shocking the cylinder). It's logical, given Cary's thoughts on the heat cycle issue, that the benefit of the thermobob is much greater if it's installed when new or very early in the engine's life. That said, it can only help regardless of when it's installed (do no harm! :) )

....at least that's the synopsis I've come up with after some research and discussions with the guys that have the first hand knowledge and experience on the subject.



Dave
 
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