2 & 4 cylinders misfiring '82 XJ650

Hi all,

Been soaking in all of the information on here for about a year, slowly working through a $500 bargain buy (that came with a parts bike!) of an '82 XJ 650 Maxim. Cleaned carbs, updated brakes, sawed a fused-on oil filter assembly off, replaced fuse box (it was in HORRIBLE condition so I had my electrician father-in-law help replace it), and we updated some more electrical system connections that were in bad shape, etc.

Just popped the top to check valve clearances. While this is all good to do (I'm told--I'm a newbie to all motorcycle maintenance), what got me started down this path is that I'd noticed a few times after riding or running it in the garage that the exhaust on the 2 & 4 cylinders were only warm to the touch (rather than scalding). I checked the plugs and 2 & 4 were fouled with oil. I knew that the first questions I'd get if I posted on here would be "have you checked valve clearances yet?", so I have. I'm mostly tight all around, and will be getting new shims in as soon as possible. I'm willing to attempt a compression test & re-sync my carbs following getting my clearances into spec, obviously (and will do so regardless of whether it plays into my problem), but I'm posting to see if anyone had other ideas regarding the misfire (they're warm, not cool, which makes me think they fire SOME of the time, at least?). I can't be offended, so please tell me if I'm way off base, have overlooked something obvious, or if my searches didn't point me to the forum topic that already addresses this issue.

Finally, I'm curious: I had quite a bit of engine oil pooled around the cam lobes when I popped the valve cover (towards the kick-stand side of the bike) that started dripping out when the gasket was loosened--enough to nearly submerge the far left shims. Is that normal? Symptomatic of my issues? Just another clue.

Thanks for being such a great community! It's definitely been a great source of information for me this last year.

Grant L.
Northern Indiana

 

Oil pooled up in the head is a good thing; it's not symptomatic of anything bad.

When you cleaned the carbs, did you wet-set the float levels? Remove the pilot mixture screws to clean those passages and replace the tiny o-rings?

Get the valves in spec, then revisit the carbs if you were less than thorough.

 

Have the plugs been replaced? How does the bike run on the open road?

 

Thanks for the responses. I will re-set float levels once I can move on to carbs. I was very thorough with cleaning the carbs (followed the popular cleaning tutorial on here) but that doesn't mean I didn't miss something.

I replaced plugs (that when I noticed the old ones were fouled--pulling them to put new in), and the new plugs fouled up almost immediately. Sounds fine on the open road, but there's a bit of popping and fluctuation on the idle.

 

Grant,

A agree with what Fitz suggest. Get the valves in spec and do a compression test. You need to "know" your bike has a viable plant. Also, do the oil sniff test. If the oil smells of fuel do not run your bike. Hope this helps.

Gary

 

Ok. Had some time to get new shims ordered and valves are all up to spec. Oil does have a strong gas smell, however. I'll be searching around on these forums for next steps! Thanks for the help so far. Onward...

 

Ok... Valves are in spec. Finally stole some time to get my carbs wet set. Hung them up and got the auxilliary fuel tank set up. Turned the valve on and started the gas flowing, and I could literally see the "fuel rail tubes" go from light to dark watching the gas creep along them from the bowl. Didn't have to hold open the throttle or anything. A few of the carbs kept on filling up and then overflowing. Looks like I need new seals, maybe new needles, etc.? Just wanted to throw this out there to make sure I'm not forgetting something stupid before proceeding. I've learned that asking saves me money when I'm doing something I'm not an expert at. Thanks!