Starter clutch slips when engine is warm.

I have a 1982 Maxim XJ 750, and the bike has a very hard time starting while the motor is hot. If I shut the motor off for a short amout of time, i.e. refuleing, it will start right back up. But if it has been sitting for more than five minutes, it won't start. Than, after about a half an hour, it starts back up with no problem. I have used prime to see if it helps, and it does not.

Also, to clarify, the problem has something to do with the starter clutch. When it is hot, it slips. Every now and then it will grab it, but usually will slip. When the bike is hot, it is very easy to push start. I can usually do it on the first try just pushing with my legs.

Any suggestions?

 

What oil are you running?

 

10W-40. My bike was burning a little oil and my oil light came one while I was on a long trip. Had to put some 20W-50 as well. Obviously I should do an oil change.
Do you think the oil causes this starter clutch slip? It just stared this season, it never slipped before.

 

In this case it very well could be.

I don't know where you got the idea to run 10W40. You need an oil change asap.

Your bike calls for 10W30 only when it's cold out, like below 60 degrees F.

In warmer weather, Yamaha wants you to use 20W40, but it's not readily available and 20W50 works fine.

And it needs to be MOTORCYCLE oil, like Castrol 4T or Valvoline or Havoline, all commonly available at various auto parts chains. DO NOT use automotive oil, it contains friction modifiers that can cause your issue. Stay away from synthetics as well, even those intended for motorcycles.

The FRAM CH6003 filter comes with both o-rings, BTW; and is also readily available. In my area, Advance Auto usually has them on the shelf.

 

I have/had the same problem,even with mult. 4 stroke oil changes.
Took the starter off,swapped the main clutch plates for old ones (just to be safe) sprayed most of a can of brake cleaner into the opening for the starter.If you can get a longer piece of the spaghetti sized red tubing it will work better (to direct the cleaner spray more accurately),and poured most of a can of Seafoam into the oil. I disconnected the TCI,probably overkill but wasn't sure how flammable the solvents might be.
Then I "started" it a bunch of times,to get the solvent on the starter clutch mechanism and let it sit over night with the battery on the charger.Started it a few more times in the morning and drained the oil,which was only a week old. Filthy dirty oil came out. Per an XJ member with FAR more experience than I,I went to Wally world and bought a gallon of Delvac (? sp.) diesel oil for 13$. Hooked up the TCI,ran that far a few min. then changed the oil/filter and swapped back the main clutch plates.(While picking up the new 6003 filter I grabbed a sheet of gasket material,traced the old one and put in a new,cheap gasket.

 

Sorry,hit the wrong key (again).To continue...It still slips,but ALOT LESS than it used to. While it isn't perfect I have 36k
miles on the motor (so a worn starter clutch) and am going to have to swap engines at some point. But not until winter, at the earliest.