82 gs850gl running lean: whats the suggested upjet?

[Guest]

my plugs are bone white, and i have symptoms of this bike running lean. i hear they are terribly lean from the factory. as far as i know the stock main jets are 115's. i would think to step a single size up:117 . but maybe you guys have a better suggestion? do you do a single step up or more? stock airbox, cleaned and reoiled, no airleaks, valves adjusted and carbs sync-ed.

thank you.

[chanceafrica]

timing is on as well

[Who Dat?]

Stock exhaust?

I would not say the factory jetting was "terribly lean", but up one size certainly would not hurt much.

Have you cleaned the carbs lately and replaced all the o-rings? Especially the o-rings on the intake tubes. If those are leaking, it almost won't matter what mains you put in, it will run lean anyway.

Where are you? Your username might give a hint, but can't say for sure. If you ARE in africa, I have no idea what fuels you might have available, but if you are in the USA, most of the fuel here has alcohol in it, which leans out the overall mixture, so maybe TWO sizes on the mains and an extra 1/4 to 1/2 turn on the mixture screw would help.

[chanceafrica]

ive read that its hard to not get the plugs to be white on a stock setup. i have not cleaned the carbs, or rubbers, but ive sprayed the carbs and intakes down with carb cleaner and have had no changes in idle (indicating there are no air leaks). i am in philly!

Stock exhaust?

I would not say the factory jetting was "terribly lean", but up one size certainly would not hurt much.

Have you cleaned the carbs lately and replaced all the o-rings? Especially the o-rings on the intake tubes. If those are leaking, it almost won't matter what mains you put in, it will run lean anyway.

Where are you? Your username might give a hint, but can't say for sure. If you ARE in africa, I have no idea what fuels you might have available, but if you are in the USA, most of the fuel here has alcohol in it, which leans out the overall mixture, so maybe TWO sizes on the mains and an extra 1/4 to 1/2 turn on the mixture screw would help.

[Brendan W]

What plug have you got ?

[chanceafrica]

What plug have you got ?

standard ngk b7es gapped

[Brendan W]

What exhaust is on it ?

[Nessism]

There is no need to modify the stock jetting. Do some maintenance like mentioned and the bike won't run lean. Replace all the carb O-rings and especially those on the intake boots. BTW, B8ES is the stock plug. B7's are hotter, which may be why they look cooked. Oh, and spraying crap on the intakes doesn't always show leaks, even when they are present. Most common telling sign is an idle that increases when hot.

[chanceafrica]

maybe they are 8es's.

[chanceafrica]

stock exhaust , ive inspected the air cleaner, b8es plugs, 115 mains. ive done a valve adjustment according to the factory manual and did the carb sync. bike doesnt idle well when hot and cuts out on occasion and is harder to start when hot. what o-rings are you speaking of on the intakes? the sync passage and one that mates with the head? i dont want to just throw jets at it but i dont know what else to do. i will replace all the o rings but i feel that if i had an air leak that was so slight that a spray down with carb cleaner wouldnt detect, then it wouldnt make me run as lean as it seems i am. thanks for the suggestions, also i have not adjusted the mixture screws but that would only affect me at idle, and not cause me to run hot after a long run on the highway, right? there is a SLIGHT popping when decelerating when its hot, possibly losing a cylinder for a second.

[chanceafrica]

pulled intakes, o rings are flat, and theres rtv smeared around the flange,suggesting a previous issue. im weary of carb rebuild kits being cheap and tolerances not being exact,ie....needle tapers,jet sizes. what do you suggest to help me get my bike in order?

[jsandidge]

No need to buy expensive carb rebuild kits. The only parts in them that are useful are the bowl gaskets. Unless yours are torn, you can re-use them anyway. You can buy the gaskets separately if you need them. You should get an o-ring kit from Robert Barr. They fit perfectly and are very inexpensive. All of the brass parts should be fine with a good cleaning. Just follow the carb rebuild tutorial on BassCliff's website. I have the same bike as you, and experienced the same lean issues. New O-rings, new boots (flanges) and thorough cleaning resolved it for me. You probably do need new boots, as indicated by the rtv on them. They are a bit pricey, but hey, you don't need to spend the money on the carb rebuild kits.

[tkent02]

what do you suggest to help me get my bike in order?

Look inside, it's possible some previous bonehead changed jets, put in some aftermarket crap, maybe even took the carbs from a different model and just slapped them on. Different needles, float heights all screwed up, torn diaphragms, partially blocked fuel passages, could be most anything. The fact that there is RTV all over it is a sure sign that someone without a clue got in there and messed with it.

I have seen all kinds of odd ball crap in used motorcycle carburetors.

[chuck hahn]

In the blued areas at the top of this section are STICKYs. Read and do as the CV tuning tutorials says.

[chanceafrica]

so where do i find robert barr o rings, and where do you suggest getting boots? just oem from a local dealer?