XS850 - Monoshock & USD Fork (pics pg 13)

Effing great! That's at least SOMETHING that we can say would have something to do with the pilot circuit!!! NICE FIND!!!

As for the exhaust, I do find it slightly odd that it's the only one that's out of spec AND it's the one giving you troubles. Could be a "perfect storm" kinda thing. Although I'm in agreement with XB that this shouldn't really cause YOUR current troubles :) Once the engine is warm you can do a compression check and see if that lower limit is holding any of the valves open, but I doubt that.

I really really hope that was your issue man! Good luck on the start up! (don't forget to use a new spark plug! ;) )
 
Dammit! Should've bought a new spark plug yesterday while I was at NAPA. Lol

Yeah, I hope that was the issue too. I am more interested in starting it up without doing the valve shim to see if it was really that air jet. If it was, rock and roll and I'll fix the shim at another time. If it's running better but not perfect, I might as well do the shim now.

Either way, yes, I'll check compression and see if that one valve being off is affecting that cylinder at all.
 
PERFECT the valves are fine ;) there is always a large safety factor in valve clearances 'specially on an aircooled machine
having them a thou or 2 undr spec wont burn or leak a valve the only thing it does is allow less room for valve to seat interface wear which can happen over time,this is part of the safety factor as well \
also it is not necassry to do the adj on a"stone cold" motor this is a falacy and another safety factor that mfg's put in service manuals to hopefully get the point across not to do it on a HOT engine once an engine is down to where you can keep your hand on there,on the block without burning it you are good to go for adjustement it all has to do with the coefficient of thermal expansion of metals the valve is the first thing to cool off but the 30-40f degree difference from "room temp" to where you almost burn your hand is not enough head expansion to even be measured at the valve gap
 
treitz said:
Soooo you're saying don't even worry about the exhaust valve on the #1 cyl?
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correct no reason to at this point.. get the goddam thing running and recheck them after a the first thousand or 2 miles the thing hasn't been run hard for a long while and 1-2 thou under spec will absolutely not cause any harm(it still has at least .006" !)
the amount under spec he is is still less than the built in safety factor for long term wear
 
xb33bsa said:
correct no reason to at this point.. get the goddam thing running and recheck them after a the first thousand or 2 miles the thing hasn't been run hard for a long while and 1-2 thou under spec will absolutely not cause any harm
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Rad. I'll post results after I fire it up again!
 
xb33bsa said:
have you ever dun a compression check ?,thread to long me no reed all of it :-X
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Haha this one is getting long. I have done a compression check in the past, but not on this bike.
 
xb33bsa said:
i ment this one git r dun !!
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It's on my list. I don't have a compression tester because I use to live right by an Oreilly who would just let me borrow one whenever I needed. I don't live by one anymore... so I either need to buy one, or drive to the next town over to an Oreilly :)
 
Good advice from XB on the lash. You certainly are running down things one at a time - well done.

I have to think that with that pilot air jet not discovered until this point, you might wish to totally re-think your notion of "cleaning" carbs. A quick and cursory clean - just hitting the high spots so to speak - by myself and I think most others, would have discovered this problem immediately. You really do have to completely disassemble EVERY part, and shoot carb cleaner through EVERY passageway. Boiling your carbs in some miracle solution, or hours in an ultrasonic cleaner are not worth a damn compared to physically testing every passageway for a clean jet of solvent running through it. I also believe that you have to understand how each system is designed so you can be certain you are not missing any pathway for fuel or air. It really is not that complicated as while systems overlap, there generally is only the pilot and main system and they both work the same way. Understand one, and you will understand the other and pretty much have a handle on all carbs in all their various designs. Knowing how it is supposed to work is key to knowing that you have actually tested every passageway. I think I would pretend I hadn't worked on them at all and clean them like I was starting from scratch - should be pretty easy by now!

That said, I would also double check the chokes (technically enrichers). The critical point is for the path to be completely blocked by the plungers. The vacuum there is pretty high at low revs, and a little leak could do a lot. So be critical in assessing the seal off position. Also, make sure the operating bar is adjusted so that plunger is not being held open a tiny bit. The plungers could seal perfectly individually on the bench, but once assembled on the bike the one could possibly be held a tiny bit open.
 
Totally. And to clarify, this is about the 4th or 5th rack of carbs I have cleaned in the last 1 - 2 years and first one I've had an issue like this with. Believe me, every single part came off of these carbs and had air/wire/fluid run through it to ensure it was clear. Honestly I will be baffled (thought very happy) if that air jet was the issue all along. At the same time, I was wrapping up this process while going through a state-to-state move and would be lying if I didn't admit that I was in a bit of a hurry to get it to the point that I could assemble it before the move. So it's possible I missed that one damn jet.

Anyway... my carb cleaning procedure stems from this discussion: http://yamaha-triples.org/forums/thread-view.asp?tid=13863&posts=31&start=1 and includes a complete disassembly and a 3 - 5 day bath in Pine-Sol mixture. I suppose it could be argued that this isn't the best solution, but it has worked in the past. Then I remove all of the parts and individually clean them before reassembly.
 
if you have any doubt about the enrichener plungers after prefoaming morbidally's checks then while the bike is idling you can physically plug the air paths for the enrichener by acces at the bell-mouth ,a golf tee should do it mahvoh-lus-lee ;)
any change in idle when plugging or unplugging this air path diktates a faulty plunger rubber seal which is embedded with a rolled over edge at the bottom of the brass piston look at it under a glass check that it is still pliable not cracked out etc
 
treitz said:
Totally. And to clarify, this is about the 4th or 5th rack of carbs I have cleaned in the last 1 - 2 years and first one I've had an issue like this with. Believe me, every single part came off of these carbs and had air/wire/fluid run through it to ensure it was clear. Honestly I will be baffled (thought very happy) if that air jet was the issue all along. At the same time, I was wrapping up this process while going through a state-to-state move and would be lying if I didn't admit that I was in a bit of a hurry to get it to the point that I could assemble it before the move. So it's possible I missed that one damn jet.

Anyway... my carb cleaning procedure stems from this discussion: http://yamaha-triples.org/forums/thread-view.asp?tid=13863&posts=31&start=1 and includes a complete disassembly and a 3 - 5 day bath in Pine-Sol mixture. I suppose it could be argued that this isn't the best solution, but it has worked in the past. Then I remove all of the parts and individually clean them before reassembly.
Click to expand...

Sounds good to me! Didn't mean to badmouth soaking the carbs (or your obviously more thorough than I thought process!) - just emphasizing it's no substitute for proving it's clean with a jet of solvent! Of course you know you are the only one in the known universe to have overlooked something! GOT to be closing in on the solution - looking forward to seeing you find it!
 
Thanks guys. I'm on the west coast, so still a few more hours till I get to it.


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Alright... I'm hesitant to celebrate too much, but I think we're REALLY close. Fired her up and she immediately sounded a ton better. Still a little popping from #1 at idle, but I haven't done a full sync yet. Slightly off idle, sounded great!! It's late, so out of courtesy to my neighbors (I know I'm too nice) I didn't run it for long, or take it down the street. I'll spend some more time on it this weekend.


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Definitely a change. Took it around the block a few times today. Running PRETTY good. Going to give it a full carb sync tonight and see how it does. Still a little popping at that #1 cylinder for SOME reason.

NEW problem... Now that's it's running better, and I stepped the needle up a clip and can actually give it throttle without it just completely bogging out, I think I might have a clutch issue. Anything above low-mid throttle and the engine revs, but the bike accelerates very little. Sounds consistent with a sticky clutch, or bad trans? I dunno. I haven't experience this before.

Clutch and clutch cable externally are adjusted. Brand new cable.

Thoughts?
 
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