New Member, First Post, High Rev when opening throttle '82 XJ650 Maxim

How's it going everyone, first time poster here and a new owner of an '82 XJ650 Maxim. Acquired the bike from a friend where it had been sitting in his brother's driveway in DC for 3 years. Without being started once and the clutch cable being replaced somewhere in those 3 years, following a battery and oil change she fired right up...and the tires somehow still looked great. Polished off some of the rust on the chrome and she drove to the Philly area in 104 heat index no problem.

Next day I took the bike on what ended up being a 1,000+ mile trip to northern Vermont. Bike is running very well and I cannot complain about a thing as I have only had to tinker with cosmetic aesthetics thus far. However, I have noticed (mostly in 4th and 5th gear) that when I try and open the throttle up the engine revs up to a very high RPM without the bike increasing in speed. If I gently release on the throttle a bit the RPMs drop to a normal level for speeding up, the bike catches and I gain speed. Again, this only happens when throttling high trying to gain faster speeds (entering a highway, straightaway, etc). Not sure if the carbs need to be tuned/cleaned up or if anyone has any other suggestions as to what this may indicate. Much appreciated in advance.

 

Clutch slipping

 

Welcome aboard. You've got some work to do if you want it to be truly road worthy. Read the "Information Overload Hour".

All cables should be inspected, lubed and adjusted. Oil should be non-synthetic jaso motorcycle specific.

Visual inspection should also include size, date codes, tire wear indicators, direction arrows, checks, cracks, inflation pressure...
The entire braking system needs to be rebuilt.

Yes...cleaned and synched.
We're here to help.

Gary H.

 

Aside from safety issues like tires n brakes, which need inspection at least, if it's running good, leave it be. Check brake lines for manufacturing date, it's printed on the line, and life expectancy is approx 4 yrs. Tires have an expiration date as well. Rear drum MUST be disassembled as the shoe is prone to delamination, with catastrophic result. Save the carb rebuild for winter. Riding season is too short to take a running bike off the road.

 

The revving symptoms do sound like a possible slipping clutch. If the cable was replaced, perhaps it just needs a bit of adjusting.

Check this out: http://xjbikes.com/forums/threads/clutch-adjustment-clutch-cable-replacement-procedure.2672/

 

"clutch issue" could be simple as using the wrong oil. Oil not designed for wet clutch can cause slippage, but that would show itself at lower speeds as well. What oil didja use? K-moe has a fantastic thread about choosing the correct oil for a wet clutch mobike.

 

First link in my signature, but it's more likely to be the original clutch is toast. Change it out before you ruin the steel plates.

 

Thank you very much for the welcome & info. Have definitely already taken a dive into the Overload page and Haynes manual, will continue to do so.

 

Appreciate the tips, weather has certainly been too nice to take this bike off the road; especially after being rock solid on a big trip up to New England. The brakes seem to be working very well and my friend (an experienced rider) who originally owned the bike thought they were awesomely responsive. Of course, I have to admit after about 900 miles of riding, when pushing the bike into the garage in neutral the front brake is dragging on the rotor on the front wheel. Definitely needs addressing, added some brake fluid there I grabbed at a Yamaha shop.

 

Thanks for the heads up on the link. Is there a more definitive way to test if the clutch just needs to be adjusted or if it is indeed "toast" ?

 

Yamaha shop was nearby in DC so grabbed some Yamalube 10W-40, new Yamaha oil filter and all new o-rings and such.

 

It's toast. If it were adjustment you'd have issues in all gears.

 

Little update. Just for clarification, this only happens when the clutch is completely released trying to speed up from ~45mph to highway speed. I only realized it was revving in 4th and 5th being that those were the only gears in which i was trying to open up the throttle. Took your info and tried opening the throttle in 2nd and 3rd to find that it does the exact same. Definitely not toast, but need to look into adjusting.

 

Adjustments are on the end of the clutch lever perch, and also on the other end of the cable, and on the clutch arm that the cable connects to there.

however, my question is: "How do you know the clutch is definitely not toast....?" Did you personally open it up and inspect every single place and disc? it can also be the oil if you used the wrong oil.......

 

Regardless if it's the clutch or an adjustment, if you keep doing this you're going to wreck the steel plates and that will increase your rebuild costs significantly. It's not a terribly difficult task.

 

Beside all ^that^, the dang clutch is definitely not new. The friction plates are relatively cheap. Just change them so you can go ride. If the clutch is worn enough it will slip in all gears.

 

Thanks for the replies, will certainly do a little work inspecting and on the plates to keep her on the road.

One question I can't find too much info on is it seems like since I've ridden the bike about 1,500 miles since picking it up that the actual throttle handlebar has become loose. Can't find much information about how to tighten it up. Doesn't affect the throttle at all and no mechanical issues, just the handlebar seems to be moving around a lot and doesn't feel too solid. Any advice on how to tighten that up would be much appreciated.

 

The throttle grip is connected to the right control switch which is secured to the bike with two screws.The handlebars are secured to the bike with four allen head bolts. Hope this helps.

Gary H.