Seeking Higher Performance from a Gen 1, ?'s - Kawasaki KLR 650 Forum
1987 to 2007 Wrenching & Mods For maintaining, repair or modifications of Generation 1 KLR's. 2007 and earlier.

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post #1 of 79 Old 02-18-2020, 09:42 AM Thread Starter
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Seeking Higher Performance from a Gen 1, ?'s

Hello, just popped to this forum
Looking for info on what i should do, currently i have 87 klr 650 and if i keep the bike i would love to get tad more power out of it. I was thinking of 705+ big bore kits but i think i would need to source the head from US and i live in Finland. So pretty much the question is should i just go with something like 685 and maybe cams and little porting or what. I dont know how much exactly the elephant makes to wheels but if internet provides right data it would be around 30-34hp rear and i would like to reach that 40hp mark but still biggest performance upgrade for me is to get fit :P but yeh justa asking others opinion to this age old question.

Thanks in advance and hello from newbie on forum.

Last edited by Tom Schmitz; 02-18-2020 at 04:04 PM.
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post #2 of 79 Old 02-18-2020, 10:58 AM
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The 1995 & earlier cylinder liners are TOO Thin at the base to be safely overbore to any thing beyond 661cc. 1996 & newer cylinders (with thicker liners) will fit our OLD engines and can be safely overbored to 692cc.
The most popular overbore size for 1996 & up cylinders is 685cc, which is 2.5mm over standard & still allows one additional oversize if ever the need be.

To go over 692cc, ones needs a 1996 & up cylinder and then have an even thicker cylinder sleeve installed into it After enlarging its opening and clearancing the water jacket around it! More parts, more labor, more money, not really worth it to most people.

Due to parts access and possibly dependant upon available higher octane fuel, like 95 MON, a Wossener 11:1 compression piston kit, in 101.0mm size & proper cylinder head porting and valve seat re-conditioning and opening up the top of the air filter box may be just the ticket for more power at a reasonable price in your homeland.

Even the stock 651cc engine can make 40+ HP with proper attention to details, as seen here, (click on the graphs) https://www.klrchris.com/ (Also click on any BOLDED items.) like air box mod

A few more mods gets a few more HP, https://www.klrchris.com/klr650-small-port-head/

klrchris had to of built his 1st set of the adjustable camshaft gears earlier in this project or for another customers bike, by the HP readings in this section.
https://www.klrchris.com/klr650-adjustable-cam-gear/
With sprocket cores exchanged, they are quite affordable and probably a wiser & cheaper single item purchase than a loud pipe, imo. But shipping cores from Finland may not be justifiable.


Of course it would be a complete waste of time, energy & money to allow a couple parts worth less than $50 USD to destroy a rebuilt engine. Are you aware of the engine Balancer Chain adjuster & spring issues? AKA the Doo-Hickey.
Here is a complete expose-ay with videos, https://www.souperdoo.com/stuff%20th...bout/doohickey

Have FUN and looking forward to reading about your rebuild in these pages.
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pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 85,000+ miles & counting
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post #3 of 79 Old 02-18-2020, 11:06 AM
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OH! And Welcome to the forum Kuutio and I thought those were very well chosen questions.

Have you read this yet? https://www.klrforum.com/introductio...kes-avoid.html

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 85,000+ miles & counting
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post #4 of 79 Old 02-18-2020, 11:09 AM Thread Starter
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Yes, i still need to order new doohickey, checked the old already since i had to change gaskets, inner side from flywheel was broken. The spring on the tensioner is rly a joke

Edit: also i have read a lot about the subject but i like to gather opinions
2nd edit: i thought i would add that i have thrown the airbox away already and have giant airfilter in place, but i need to find new muffler, yes, it does flow great, but it flows so great that i can be heard to the other side of town

3rd edit: i just keep getting more stuff on my head, do you think is it worth it to get bigger front end on the bike or just better stuff inside those small tubes. I have seen both and people say both are good options but what do you think. I like to have pretty stiff ride so i cant but hate the suspension at the moment. Thats propably first thing i want to change and maybe new wheels since i want to turn it into supermoto rather than traveler but still keep the big tank for possible trips.

Last edited by Kuutio; 02-18-2020 at 11:17 AM.
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post #5 of 79 Old 02-18-2020, 11:38 AM
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Ditto on Paul's comments on the power issue, if the bike runs well and doesn't burn oil, I'd do the usual mods (KLX jet kit, air filter, snorkle-ectomy and/or L mod, silencer of choice) which gets you to 37hp or so.... If it needs a rebuild, the 685 will get you another 2-4 but you'll need a post-'96 cylinder. porting, cams, etc. etc. can boost power but it quickly becomes a point of diminishing returns IMO.

On the suspension, the stock 39mm tubes aren't that big compared to more modern offerings, but that isn't that important IMO; the bigger issue is the damper rod setup and it's very poor damping curve....coupled with the stock Gen1's inadequate springrate. I recommend Cogent's DDC kit https://www.motocd.com/product/ddc-complete-package/ which completely transforms the fork action. Second choice would be Racetech's Cartridge Emulators and springs but they take more work to install.....there are other options but it goes downhill from there.

Plenty of people have done KLR fork swaps but there are many issues to consider and it isn't easy or cheap; with the DDC kits, I am very pleased with the front suspension functionality on my Gen1's. For a Supermoto, I'd consider adding a fork brace (Eaglemike's is my recommendation)

Cheers,
Dave
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post #6 of 79 Old 02-18-2020, 11:39 AM
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an older post I made on the KLR fork swap issue:

Several things, the biggest is a new front wheel/hub and brake system. As I told you in that other thread, there is no free ride and the USD fork conversion has it's own set of issues to deal with.... Not saying there isn't an allure to it just that there are good reasons more folks don't do it. When I did the math prior to making the decision to stick with the stock forks and go with Cogent's DDC's, my total came to $2,000 - $2,500 for the USD fork conversion vs. about $350.00 and less than an hour for the Cogent stuff.

After the additional expense, fork rebuilding, respringing, revalving, dealing with the rear suspension travel issue, gauge cluster, speedo, turning radius issues......you still have a smaller hub with a smaller axle, smaller bearings and when compared to the SV caliper 320mm rotor mod, a much smaller brake caliper, pad and rotor......all of which are fine for MX use and less fine for dual sport use.

There is no doubt as to the superiority of the modern MX fork.....but unless you have it resprung and revalved properly, it isn't going to work as good as a set of DDC's and springs in the stock forks.......and even if you do those things, the rest of the KLR isn't up to making full use of them anyhow.

I'm just making you aware of all the issues; if you still want to do it after all that, knock yourself out.
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post #7 of 79 Old 02-18-2020, 11:42 AM
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With (a) 5th posting, this thread should move into the 'Recent Discussions' column and you will get better answers about your desired suspension action & steering precision while on hard-pack or asphalt highways from guys like Maverick9611. Dave Pelletier is more of an off-highway guy, but I'm sure his bikes would still hustle down a twisty piece of asphalt even on knobby tires and pots in gravel roads would just almost disappear.

I hope that you enjoy Exploring all sections of the klrchris and souperdoo sites, they are a treasure trove of KLR information.

ps, I really don't Type. And Dave has already found this.

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 85,000+ miles & counting

Last edited by pdwestman; 02-18-2020 at 11:47 AM. Reason: ps added
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post #8 of 79 Old 02-18-2020, 12:06 PM
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Quote:
Originally Posted by pdwestman View Post
The most popular overbore size for 1996 & up cylinders is 685cc, which is 2.5mm over standard & still allows one additional oversize if ever the need be.
Just for information only: What is the source/availability and size of the, "one additional oversize," piston and ring set for a 685?

“You better put down that gun. You got two ways to go, put it down or use it. Even if you tie me, you’re gonna be dead.” "John Russell" (Paul Newman), Hombre
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post #9 of 79 Old 02-18-2020, 12:36 PM
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Quote:
Originally Posted by Damocles View Post
Just for information only: What is the source/availability and size of the, "one additional oversize," piston and ring set for a 685?
https://www.eaglemike.com/692-forged...-kit-692pk.htm

beyond the 692, you'll need a new sleeve.

Dave
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post #10 of 79 Old 02-18-2020, 12:39 PM
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Quote:
Originally Posted by pdwestman View Post
With (a) 5th posting, this thread should move into the 'Recent Discussions' column and you will get better answers about your desired suspension action & steering precision while on hard-pack or asphalt highways from guys like Maverick9611. Dave Pelletier is more of an off-highway guy, but I'm sure his bikes would still hustle down a twisty piece of asphalt even on knobby tires and pots in gravel roads would just almost disappear.

I hope that you enjoy Exploring all sections of the klrchris and souperdoo sites, they are a treasure trove of KLR information.

ps, I really don't Type. And Dave has already found this.
Thanks; yes my usage and experience is heavily offroad biased. That said, my bike do very well on pavement though they aren't optimised for it and several people that run mainly pavement have posted similar positive experience with the Cogent upgrades - ultimately good suspension is good everywhere though it may be more noticeable offroad.

Dave
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