New Member

Hey, I'm new to the forum and I own a 1981 XJ-650. Super cool vintage bike. I bought it for 750 and drove 3 hours to get it in an old Crown Vic cop car with a uHaul trailer. I just got finished with a maintenance items, new plugs, battery, ATO style fuse box, air filter, and added a fuel filter. I also go new grips mirros, decals and am taking it to a local shop to get the carburetors synced and adjusted since I live in an apartment and don't have the space to do it.

 

The valve clearances need to be checked and adjusted FIRST.

Quite often a shop that doesn't know what they are doing will simply lie about this and tell you "it's fine." It won't be. Neglected long enough, you'll damage the motor. Often neglected by previous owners.

If the valves aren't in spec; there won't be any true carb synchronizing going on. What the shop tells you about this will be a good test of whether or not they're pulling your chain. Ask them what the clearances were; what shims were in there, what shims they installed; and the final clearances. If they can't or won't provide that information (or try to tell you it doesn't matter) they DO NOT know what they are doing.

 

Hi and welcome!
Please be sure to rebuild your brakes, front and rear. If they are original, they are getting close to 30 years overdue for service. Rear shoes could delaminate, causing wheel lock and a wipeout. Front hydraulic lines or seals could rupture casing brake failure! Very important!

 

Welcome pbj! Like peanut butter and jelly I presume? Both of the above post are very true. These bikes are relatively easy to maintain and work on and parts are pretty much readily available. If your shop is blowing smoke up your a$$ just ask questions here. This site is a treasure trove of information and help.

 

+1 on the above.
Have your clearances checked BEFORE carb synching. Ask them to see their YICS blocking tool. Deer in the headlights look=DANGER! You CAN'T properly sync a YICS engine without having the YICS port blocked. (That is, if yours is a YICS engine.....as noted by the covers on both sides of the engine "YICS"...
(as noted in the picture below)

IMAG0375 by buellosaurusrex, on Flickr

 

+1 on the above.
Have your clearances checked BEFORE carb synching. Ask them to see their YICS blocking tool. Deer in the headlights look=DANGER! You CAN'T properly sync a YICS engine without having the YICS port blocked. (That is, if yours is a YICS engine.....as noted by the covers on both sides of the engine "YICS"...
(as noted in the picture below)

IMAG0375 by buellosaurusrex, on Flickr

Oh yeah, and welcome!

 

I've read up on the importance of checking the valve clearances and such. It's very detailed in shop manual that I have. I think I can tackle that one, since I was a proper auto mechanic for 6 years. Where do I find the shims, for the adjustment ? I found out form the previous owner that the rear brakes are new and the front brakes don't look bad, I must take a closer look at the bits of the antiquated hydraulic system to make sure it passes PA state inspection. As far of the the YICS system, is that on all Maxim 650's or just ones with the YICS printed in the engine ?

 

welcome !!

 

Welcome, from Western NY state!

 

You can get shims at a Yamaha dealer (expect to pay around $25 each) or from XJ Forever at around $8 each for the aftermarket shims. Click on the link at the upper right corner.

The Motion Pro valve tool can be found here.

Disconnect you battery first. Here's why.

I believe your '81 model is non-YICS. If the crankshaft cover doesn't have the YICS badge then it's not.

 

Also I believe hogfiddles has a shim pool. PM him with any questions as to how the pool works.

 

Definitely check out xj4ever for parts. There's a lot of good advice and data in there amongst the parts list.

 

I took it for a ride to get some gas today. Didn't go as planned, It was running strange, I had to jump it to get it started and ran like rubbish. I was riding back and got the speed wobbles as my front tire went flat close to home. I'm thinking I need to put some generator brushes in it, get the valves checked and or adjusted, carbs synced and a new front tire. Otherwise, very pleases in the bad ass look of the old XJ, I plan on keeping it for a while.

 

Sounds like a plan.

Read this: http://xjbikes.com/Forums/viewtopic/t=41400.html