1981 bagger help

[ossjughead]

Ok so i am ready to pull hair out my 81 xs 11 bagger keeps going lean i have 170 to 180 psi comp carbs have been all redone 3 times to check them wont rev over 7500 idles great starts great runs down the road ok as long as you dont go near 7000 rpm have checked wires wiring front to back have no leaks anywhere intake boots new. Drove it 50 km stopped checked the plugs 1 was black 234 where great drove back home checked plugs ALL F&^%#@$%^#@^*$**$* white LEAN as ****. PLEASE HELP i am all out of ideas i am missing somthing but i have no idea what so any ideas would be great.


thanks Jim

[tarzan]

You say it runs great till 7000 rpm?Maybe your mains are a little small.
Did it used to work right?Or have you upgraded exhaust or aircleaner?

[ossjughead]

everything is stock

[motoman]

Could be several culprits. Stock mains should be 110's with stock pipes and stock air box. That's just a start, but will eliminate one culprit.

[John]

Per haps one size up on the mains, and raise the jet needle up a little. On your carbs they aren't adjustable per se, but there is a trick of using a thin washer under the c clip on the needle to raise it. If you do a search you should find a few posts pertaining to this matter.

[Big Daddy Funk]

Slow and easy does it

Just to narrow it down a bit. Check the ignition timing with a strobe(Fmark). Clean the spark plugs. Take the bike for a short ride and accelerate rpms up to 7000. Shut the bike off and pull in the clutch and coast(brake) to a stop. Check the plugs again. The differences in reading a plug can be subtle. White or light grey on the insulator with blueing on the electrode is hot (lean) A light tan or grey (with no blueing on the electrode) is normal.
This does sound like a fuel related issue. Checking the plugs at the point the engine is misfiring is a good place to start diagnosing.
There are lots of posts with guys having the same frustration. With a methodical approach and patience we'll get it running tip top.
Let us know what you find. Thx Rick

[dbeardslee]

Might try it with the gas cap cracked open. Sometimes the vent gets plugged up and won't let the gas flow through like it's supposed to, and the problem usually makes itself known at higher rpms. Easy enough to check and fix. JAT

[ossjughead]

OK so i knew it was not a fuel problem and started to check all the wirring and after looking and looking i noticed that i had oil on the floor under the bike well after looking where it came from i thought it was not right cause it sure looked like it was coming from the mag cover so i tookk it off and well oil ran out of it so i think i found out what was the problem with not being able to rev cause ev erything was soaked in oil and am hoping that that would have caused the leaning problem cause it not getting the correct spark. Let me know what you guys think

thanks Jim

[dbeardslee]

If it was coming out from under the mag cover it's probably a leaking o-ring on the galley plug. DO NOT RUN with the cover off - it'll blow that plug clean across the room. That being said, I doubt it's the problem for not getting past 7k. Have you done the pickup coil wire fix?

[ossjughead]

No its the seal in behind the pick up coils and soaked everything in there with oil

[dbeardslee]

Sorry - thought by mag cover you meant magnito cover - on the other side.

[ossjughead]

no it was my fault thats what i put but ment the pick up coil

[dbeardslee]

As far as the oil is concerned, it could be coming from the seal, but it could also be coming from the galley plug on that side. It looks different than the other one - a flange-type bolt that sits just under and to the rear of the timing cover. The timing cover itself keeps it more or less in place - you can't get it out without removing the timing cover. It too has an o-ring that can leak. If you check it make sure not to apply too much torque putting it back in - it's made out of pot metal and it doesnt' take much to snap it in two. Also, if you take it out with the crankcase full of oil, your going to get a pretty big mess. It's not a good thing to have it squirting oil all over the place, but I'm sceptical that it would cause the problem you describe.

[79XS11F]

That's the crank end seal and it can be changed without splitting the cases. The original factory seal had a lip on it so the trick it getting the original seal out without damaging the sealing surfaces. Once the original seal is out a new lip less seal can be pressed into place.
So she's still running lean. if the carbs are CLEAN so all fuel supply channels are clear you can confirm the float levels and if they are all good then perhaps move up 1 or 2 sizes on the main jets. the originally released 78 model came with larger main jets and the jets were the same across the board. things changed quickly to keep the bikes within EPA specs and they started leaning them out. More so on the outer cylinders then on the inner cylinders. Also note that if the engine is starved for fuel it will not rev as it should because there's just not enough fuel for it to run any faster. if your getting white plugs and still not reving over 7K then she is in deed lean.
Rob

[dbeardslee]

The plug I was talking about is part #43 in this diagram -





The fiche just calls it 'plug, straight screw'. I thought the crank seal was up higher, but I've been wrong before. Might be where the oil is coming from, but I agree with Rob - your 7k problem is probably in the carbs.