82 xj650 running problems

I can get my bike to start with the choke on. As soon as I try to take the bike off choke it will run fine after warming up and then eaither 1- the bike will start to idle way high, or 2- the bike will drop below 1500 rpm and just die. I adjust the idle control after warm up and it tries to die to around 1200-1500 rpm. It will stay there while sitting still but once I take it out for a ride and get from point a to b it is idled way up to about 2 to 3000 rpm. I dont know what is going on. If anyone could give me some pointers or maybe the cause of this it would greatly help alot. Id just like to have a good running bike. Thanks and would like to hear from you guys.

 

Your problem sounds like carbs to me. Check the boots that join the carbs to the engine and see if there are any cracks in the rubber also check the rubber caps on the top of these boots as they will get old and crack.
If there is any air leaking in from these areas your idle will increase. This will lean out your air/fuel mixture and that is not good.
I have been fighting with carb problems myself lately and this winter just completly rebuilt mine.
I found the throttle shaft and fuel pipe seals were completly cracked and needing replaced. If carbs leak air they will give you problems.
I am about to put my bike back together and see if I got it.
Good luck with yours man.

 

The problem is the carbs, or a vacuum leak, or a combination of both.

You're going to need to pull and clean the carbs, and ensure there are no vacuum leaks, as posted above. You'll need to bench-sync them afterward, and check and adjust the float levels if necessary. Once back on the bike, you'll need to do a running vacuum sync. AFTER you've checked the valve clearances and adjusted any that were out of spec.

If you do all of this as spelled out, your bike will start and run fine. You are simply seeing the effects of a lack of proper maintenance over the years.

Do a forum search on "carb cleaning;" get yourself a service manual, and do everything in the "maintenance" section, leaving nothing out. And it'll run great. Skip steps, try to find quick fixes, take shortcuts, and you'll be at it a while, until you decide to wade in and do it right.

Between a service manual and this forum, all the necessary info is available. You just have to do the work.

 

Well I've done checked the carbs and they are fine. Come to find out the rubber boots leading from the block to the carbs are all dry rotted and cracked. and is drawing in air real bad. I believe I've found the problem. The only thing to do now is to try and to find those boots to replace mine unless anyone knows of an little rigging trick to continue using mine and try to eliminate the air intake of the cracks.

 

A lot of times the cracks don't go all the way through, and can be packed with RTV or painted with Liquid Electrical Tape.

If they're truly cracked all the way through, the best bet is of course to replace them; however be forewarned: The manifold bolts are prone to breaking so it has to be done very carefully.

Finding the parts should be no issue; our resident parts source, XJ4Ever carries them. PM member chacal, or click the logo/link in the banner at upper right on this page.