needle jet - ugh

[psycoreefer]

still rich, and a stumble at 3k

I'm going to keep going in this thread because It has the most history of my bike.

Well I put the carbs back on it, synched and adjusted pilot screws and it seems to rev easily and starts easier then before but It is still rich at idle/low speed. I mean really rich like black as night on the plugs.

I also have a stumble at around 3k, only under load like taking off from a stop light, and today on the way to work I went over some rail road tracks and lost 2 cylinders for about 10 seconds.

Do you all think that the stumble is carb related, do to the rich idle, or more likely a pickup coil issue? I was thinking pickup coils because of the way it cut out going over the railroad tracks. I don't think any of the other connections would cause that because I just went through and cleaned/dielectric greased/tightened all of the ignition connectors.

I did check the pick up coil wires and one tested bad so I replaced it, should I assume that if one is bad that they all are?

I couldn't get 3 of the pilot jets out but did clean them with carb spray and compressed air, so maybe my float height is to high causing the rich idle? I didn't mess with the float height when I cleaned the carbs, just looked across to check that they were all even.

How much does float height affect high RPM mixture? Above 4K it is on the lean side, mostly white with just a touch of tan on one side of the plugs, however I do have an aftermarket 4 into 2 exhaust so I'd expect it to be leaner.

I was hoping to get this bike to where I was comfortable riding it so I can tear my honda shadow apart to fix the fork seals and not have to drive my truck.

[DiverRay]

The float height has A LOT to do with idle!! Pull the carbs, flip them over, pull the float bowls and RESET the height! They need to be about 25.5mm, IIRC. I would put them at 26mm if you are rich. I am running my '79 at about 27mm. The higher the float hight, the LESS fuel in the bowl. Don't forget to verify that BOTH floats are the same on each carb, and all 4 carbs are the same.

[psycoreefer]

well I pulled the carbs and measured the float height. The highest (lowest fuel) was #4 at 27mm. I adjusted the rest to match, although they were all just slightly lower, like about 26-ish. Would anyone recommend going higher, like 28 - 29 if I'm still rich?

[DiverRay]

I would only go .5mm at a time after this adjustment!!! you are getting into the "touchy" range, and VERY LITTLE is needed to go into the "problem" stage.

[psycoreefer]

Thanks Diver, you've been a big help. The plugs after letting it idle and a short ride between 2k and 4k seem to be about perfect so I don't think I want to adjust the floats again.

The stumble is a lot better now but not compleatly gone. Is it possible that the stumble is now a "lean" stumble because I know if it was lean at high RPM before its going to be more so now. It also seems to have moved up a little bit from 3 to about 3.5k. The bike also has considerably less pull from 4K up. What do you think?

I've also ordered a set of rebuld kits from georgefix on ebay with 140 mains, hopefully that will take care of it.

On the positive side I can take the carbs off in like 15min and 20 to put em back. Not sure why eveyone complains about the stock air box.

[ross]

lifestyles of the poor and unfortunate.....

hey there psycoreefer....nice 2 c another michigander here....i swear after reading your thread, this carb problem must come from the water....anywho, just wanted to say "howdy" and tell you "may the force be with you"...i currently am in carb h*ll and hope 2 be figuring it out this weekend....check out "the $64,000 question...." thread i started....sorry i didn't see you sooner, but i actually do have a job here in michigan....go figure....talk 2 ya later....ross

[egsols]

Here's a full set of carb parts for under $100

http://cgi.ebay.com/ebaymotors/79-81...QQcmdZViewItem

Seller say off an '80 but they sure like 79's to me.