TOPIC:

Hi all, I recently purchased a 79 SR650D2. It's in good shape(brakes, tires, shocks all good condition, shifts perfect). My friend and I are planning on tearing it apart this winter. Our purpose is more to tear the bike apart and put it back together (rather than modify it heavily). Currently it starts and runs, but will usually die at high RPM's, indicating a carburetion problem. We are both mechanical engineering students with reasonable mechanical abilities. But we're not sure how deep to go into the engine and tranny. The bike has 22000 miles. What items in the engine do you recommend replacing/adjusting, and what items are better left untouched. Any items troublesome for this year. Our plan is to just take the engine apart, and replace rings and gaskets. Don't know much about these bikes yet. Any comments words of wisdom on starting an overhaul project. Thanks!!! Also, we have a budget of about 500-1000 spacebucks

Are you saying it's only problem is a high idle? I'd say adjust your idler screw, take a compression test and ride the scoot! Just me but I have never taken apart a good running engine! If the thing has the compression of 0-50, leaks oil like the Exxon Valdes, sounds like a cement mixer or smokes like tires on a brushpile OK. OR do you guys want to build a Illudium P-232 Space Modulating KZ650...THAT WOULD BE A DIFFERENT STORY. yOU WOULD NEED TO TRANSFER THOSE SPACEBUCKS INTO SOMETHING MORE LIKE THIS........

It is my opinion that every man should at least attempt to take an engine apart and put it back together, if for no other reason than to say that they have done it.

THAT'S a great attitude, bison.
Welcome to the forum.

Welcome aboard, Bison, nice 650. I kind of agree with Gris, but if you´re determined to do it just for the hell of it I´d suggest you get hold of a repair manual, preferably a Kawasaki Facory Service Manual but a Clymer manual will do too. The 650 engines are pretty easy to work on, if you´re mech. eng. students you shouldn´t have any problems.

Until you get a manual, check the KZR filebase, it´s under "KZ information" in the top menu - do a search for "650", lots of good info there. Here´s one for starters, an article by Dr. Rod on dismantling a 650 , pdf format:

kzrider.com/component/option,com_docman/...d/gid,339/Itemid,49/

And a couple more, 650 engine stripdown, refurbish and rebuild:

kzrider.com/component/option,com_docman/...d/gid,230/Itemid,49/

kzrider.com/component/option,com_docman/...d/gid,229/Itemid,49/

kzrider.com/component/option,com_docman/...d/gid,228/Itemid,49/



Have fun.

Post edited by: OnkelB, at: 2006/10/02 17:00

I think it's a good idea to tear apart bikes that are in need of it, but your machine doesn't seem to be one of them. I also appreciate that inquisitive nature, I've taken things apart and never got em back together.

But to answer your questions, these engines are very solid when taken care of, and if you want to do a top end job that would be about it, considering the mileage. I don't see a need to go into the tranny or bottom end. But drop the oil pan and see what's in there.

There is plenty of other maintenance work on that old bike that should be checked out. And if you plan on riding the bike, or even selling it, you need it safe before anything else.
: Brakes, forks, wheels, electrics, carb rebuilding and once you get involved in those you may decide to keep a good running engine in one piece.

Why don't you get a factory manual, go thru the five things above and see what you think then?

You've got to ask yourself,

"Do I wanna ride or do I wanna wrench?"

IMO if you don't have another bike and you don't wanna ride, you should be tearing apart a ford 260 or one of those Ford Yamaha motors with the shims. Something along those lines. If you don't have another bike and you wanna ride, compression, spark, mix. If all are there at the right time you'll be riding. She isn't gonna be worn out at 22k miles.

There are plenty of free to $100 bikes available from now through Dec that will benefit from tear down and rebuild. Just start asking around.

If you're in Atlanta, you can go through my Honda CX500. I won't charge you a cent but I want it back in better shape than it leaves.

-Duck

bison wrote:

It is my opinion that every man should at least attempt to take an engine apart and put it back together, if for no other reason than to say that they have done it.

I've taken apart engines in my bedroom and thoroughly recommend a clean sheet on the floor - you never lose even the tiniest piece.

It is my opinion that every man should at least attempt to take an engine apart and put it back together, if for no other reason than to say that they have done it.

Aha! A fellow engineer. I would have guessed it even if you hadn't said so. Stick with a top-end job the first time. That'll be enough fun.

bison wrote:

Hi all, I recently purchased a 79 SR650D2. It's in good shape(brakes, tires, shocks all good condition, shifts perfect). My friend and I are planning on tearing it apart this winter. Our purpose is more to tear the bike apart and put it back together (rather than modify it heavily). Currently it starts and runs, but will usually die at high RPM's, indicating a carburetion problem. We are both mechanical engineering students with reasonable mechanical abilities. But we're not sure how deep to go into the engine and tranny. The bike has 22000 miles. What items in the engine do you recommend replacing/adjusting, and what items are better left untouched. Any items troublesome for this year. Our plan is to just take the engine apart, and replace rings and gaskets. Don't know much about these bikes yet. Any comments words of wisdom on starting an overhaul project. Thanks!!! Also, we have a budget of about 500-1000 spacebucks

engineers huh?well from experiance with engineers youll definately want to get the architect and interior designer on the payroll so you can get the right color of gaskets to go with the motor.make sure to have all materials tested by outside lab ,and for god sake dont forget to get a mechanical inspection.and when it doesnt fit back to together quite right just remember to use a calibrated ball peen hammer! oh i love engineers! thats gonna cost me!

Post edited by: wireman, at: 2006/10/03 13:43