whats goin on??? 88 xr600r

sometimes when i go out to start the bike, i begin to crank it over slowly until i feel the compreshion stroke take place but at time is i will slowly crank it over about 30 times and no compression what so ever, then all of a sudden itll be there, it comes and goes some days it will hit every time and others never

also when i get compression i stand up and kick it hard and in the kick starter there will be a slight pop and all of a sudden it will catch any ones elses out there do this?? again its a 88 xr600r with about 80-100 hrs on it, runs great when starts and doesnt burn oil

I am willing to bet that the auto-decompressor on the cam is loose. My cousin's '96 XR600 did the same thing (The motor never changed in all the XR600R's). The auto-decomp loosened on the cam, and then caused it's exhaust valve to burn up.

We solved the issue by removing the auto-decomp from the cam all together. You have to have a machine shop plug the oil holes in the cam. We ended up doing a full re-build on the motor. Now it's a 629.

You may think I'm nuts, but I have never seen that bike start on the first kick untill we removed the auto-decomp. You have to still use the manual lever, but the bike starts easier now than it ever did.

The pop in the kickstarter is a honda common trait. The gears that engage when you kick it can slit a tooth sometimes. It's a scary sound, but I don't think you have to worry about it.

ok cool thanks for the info, i thought it would be somethin with the auto decomp

another question my hot start lever wont let the bike start when its hot and when its running if i pull in the lever the bike dies is this normal to? lol thanks

That's because it's not a hot start lever. It's a manual decompression lever. Not sure why you're having hot start issues. If you find top dead center, pull in the decomp lever, and release it as you're kicking, it should start just fine. The auto-decomp can hold an exhaust valve open, so you may just be having compression issues and not really hot start issues.

BTY, on an XR600, don't pull the decomp lever as a kill switch, or use it as a jake brake. On the 600's, they say it can cause problems.

yeah i never use it, the one time i did use it was to try to start the bike, but if i do pull it in while kicking it over theres no compression and it doesnt even try to start

Well, the auto-decomp & the manual decomp both effect the same valve. If there is an issue with the auto decomp, the manual will not work correctly either. I think you're going to have to have the cam checked out.

If you do end up removing the auto decomp, you are going to have to use the manual to start the bike, otherwise it will break your leg. (not really, but it won't feel good).

The idea with the manual lever is, find TDC, pull in the lever, and release it as you kick. About half-way though the kicking motion.

But, with auto decomp problems, you'll have issues getting the bike to run at all. Being that you can get it to run sometimes tells me that that problem is in it's starting stages.

Before my cousin's bike died competely, we had lots of starting issues, and noticed that in top end of the powerband, the bike ran like crap, coughing and sputtering.

I would take it apart & check the cam. Being it's an 88, I might just have a top-end re-build done. If you really want, you can bore out the cylinder to a 629. which is what my cousin did. Now that bike runs like it never did before.

haha ok cool, yeah every once in a while you will be riding and all of the sudden the bike will start lunging like theres water in the fuel so yeah prob somethin to do with the auto decomp, i dont think this bikes even worth rebuilding but who knows thnaks anyways for the info

All big bore XRs I have ever owned, and there have been many, will loose the feel of hard compression if the bike has been sitting too long. I am not sure what causes this but it has never been a problem. You just need to try harder to determine compression stroke and try to start. Eventually the bike will start and the problem will disappear after bike warms up. If you start and run bike every several weeks you will never have this problem. I believe the problem is related to the position of piston and valves during the storage period because the occurrence is not consistent. If the last thing you do prior to storage is to position the piston at beginning of hard compression then the possibility of "loosing the feel" will be reduced.

Once the feel of hard compression is back to normal then push kick starter down until you feel compression. Then pull in decomp lever and push down another one to two inches. Then release decomp lever, return kick starter to top of stroke, and with throttle off push kick starter down. If idle is set correctly and bike is tuned correctly the bike will run.

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