B6 idle/running problem

[originalsin]

ok so so i bought this bike off a friend, its a 97 600s. about 2.5 yrs ago he put a holeshot pipe on it rode it for a few months and then it sat in his garage until now. he had the holeshot stage 2 jet kit for it but never put any of it on. i pulled the carbs off yesterday and cleaned them, one of the buckets had alot of junk in it the others werent to bad but i cleaned all fo them anyways (only pulled the buckets off no that top cover, maybe this was where i went wrong?) in doing so i swaped out the jets. only problem is i didnt notice there were two sizes of jets in the carbs (this is my first bike) but i didnt notice the one that was gummed up that had ben on the end was smaller (98) so i figured smaller jets on the outside, larger on the inside. so i put the 108's on the outside and the 110 on the inside. buttoned it all back up, put in new plugs, changed the oil, some fresh gas (only 89) and fired it up after a few attempts.

now the problem is it will not run unless the choke is off, even after it has been warmed up, and it idles at like 3000-3500rpms, i can back the choke off just a bit and it will come down to some but once i get like halfway closed idle gets like below 1000 and the bike dies.

when it is running and it is at 3000 it is smooth, not breaking up or anything but when i give it gas it will rev up sometimes and other times it will sputter and break up, im guessing because of too much fuel?

other thing im thinking is maybe its a vacume line somewhere or something and its not letting enough air in, becuase when i hit the throttle those little aluminum gate things that are like vacume actuated seem to flutter but not open fully. i also realize my carbs may need to be sync, idk. the only lines i have running to the carbs are the gas line (obv not vacume, and i have all 4 nipples on top of the carbs blocked off. there are those 2 larger nipples inbetween carbs 1 and 2  / 3 and 4 but i believe those are just fuel overflow lines correct?

also, when the carbs were off i did check to make sure the floats were working properly.

and i never installed any needle spacers that came with the kit, because im not sure what they do or anything. didnt install the timing advance thing either.

but yea, i know that is alot but i figured the more info a supply the easier it will be to help me out

thanks in advance

[Red01]

Did you get the instructions that came with the kit? If so, go back and follow the instructions, they'll tell you how to finish the job in the top half of the carbs. If not, contact Dale @ Holeshot and either have him tell you what you need to do or send you the instructions. (It'd be handy to have them in case you need them for a future reference.)
Holeshot's kits are designed to work their best with a 5* advancer, so you should go ahead and install that, too - though that shouldn't be a part of any of your current problems.

You can either install same size jets across the board, or a size smaller on the outboard cyliders, like stock.

You said it's a Stage II kit, so I assume you ditched the airbox and installed the K&N pod filters, right?

[pmackie]

It sounds to me like you idle circuit is your problem. This would mean the idle mixture screws, pilot jet and pilot air supply.

I assume you mean that it won't idle or run at low rpm's unless the choke is ON, right? If this is correct, I would start with the following:

1. Adjust the idle mixture screws OUT 1/2 turn at a time. You will want to carefully screw them in until they bottom and then turn them out. If they have never been set (except by the factory) they may not even be the same. If so, start a 2-1/2 turns out, then try 3 turns out, then try 3-1/2 turns out.

2. If the bike won't idle without the choke and you are at 3-1/2 turns, you likely have other problems. Take the carbs apart and ensure that the pilot jets are not blocked. Blow air through all the supply holes, etc.

3. Look for any air leaks. Ensure all vaccum tubes are blocked or connected to something and that all connections between the carbs and head are tight, no cracks, etc.

[originalsin]

yes i have the k&n filters installed, and ill go ahead and install the timing advancer.

i feel dumb asking this but where are the mixture adjustment screws? lol iv been looking for them and cant seem to find them anywhere.

and yes, choke ON

ill contact holeshot and get the instructions tonight.


also, a sidenote.

i noticed a slight knocking noise, is this regular on a bike? im a car guy and to me it doesnt seems right but idk, its seems to be happening all the time, and i know with most autos youll only start to notice rod knock on decel.

[originalsin]

update: i pulled the carbs again and cleaned them again and it is running a bit better, i can get it to idle with the choke off sometimes, but its touchy. i still can find the mixture adjustment screws lol

i think i just need to get the carbs sync'd, or do it myself, it doesnt seem that hard


btw, what should i be idleing at? 1500ish?

[pmackie]

I'm not completely familiar with the 1st Gen 600...If you don't have a manual, try to download one, or look at for some pictures on other threads.

The Mixure screws are under the carbs, near the intake side. They are often covered with factory "plugs" that need to be drilled out before you can see them.

If you really have a "knock" I'd be concerned. These bikes do have a little tappet noise (slight "clatter"), but if you have a steady "knock", something is amiss.

[originalsin]

yea a friend stopped over and said it prolly just needs a valve adjustment

[Red01]

These are pics of the bottom of a 2G B12's Mikuni carb, so your B6's Keihin will look different (especially the float bowl's internals), but the screw you're looking for will be in pretty much the same place.

With the plug still installed:
See "A/F Plug -->" at the bottom of the pic.



With the plug removed to access the screw:

[originalsin]

thanks alot