i am an idiot... please help!

gintree wrote:

:woohoo: :woohoo: :woohoo:

That's what I needed! Thanks loudhvx, Gane and George! The bike is a chain LTD and the carbs have the non-adjustable needles.

That's a lot of info so let me know if I got this straight:

-First I'll do a more in-depth attempt at setting the air screws.

-If I'm still having trouble, try drilling out the pilot jets.

-If I'm still having trouble, get adjustable needles and set the needles up a clip position from 2 from the top to 3 from the top.

I'll keep yall posted.

loudhvx - once I get these tuned up, I'll give the choke mod a go.

Thanks again

gintree

Yes, that's the plan I would take. Learn how to do the "lean drop" method for setting mixture screws. For that you have to use a more accurate tach than the one on the bike. I use a cheap actron tach, and can give pointers on that if you need.

Also, It was probably mentioned, but make sure the ignition is 100% correct before making any irreversible carb changes. That means veryify the timing at idle and full advance (sometimes it advances too much if the rubber pads are missing on the advancer arms). Also, a very common problem on the 550 advancers is that the springs get weak. You need a strobe timing light and accurate tach to verify when the advance begins and when it is all in. With weak springs, the idle can be unstable since the advance can jump in occasionally. You can't get new springs, but you can slightly squeeze the loop on one end of the spring and that is usually enough to restore it. Using a timing light will also show if you are getting misfires.

If you get a halfway decent idle, That would be the time to do a synchroniztion on the carbs before drilling. You'll need a

YAAAARRRRGGGGG! More problems!!!

I got the air mixture screws set richer and the bike seems like it's running pretty smooth off the line, but the mid-range of the throttle seems lean. It kinda sputters some around half throttle, so I figure this is time to adjust the needles.

Yesterday, a buddy of mine comes over to check out the bike and help with the tune and he takes it for a spin to get a feel for the carbs. When he was riding he noticed that it's only running on 3 cylinders. I'm really new to bikes, so I don't know if it had only been running on 3 cylinders and I hadn't noticed, or if the symptom was new. We pulled the plug and squirted gas into the cylinder and started it back up. This seemed to jump start that cylinder as the header started warming up at that point, but I don't know if it was firing intermittently or what.

So I guess my question is if this could be related to the carb tuning issues or if this is something unrelated. I imagine I can get the carbs running right until I figure out what the problem with this cylinder is. Any suggestions? I'm jonesin' to ride this thing!!!!

Well, all electrical issues should be resolved before doing any carb tuning, but you should at least make sure the #3 carb is getting fuel. Do the fuel level check I mentioned.

manual

OK... so here's the update. Upon reflecting all the events leading up to the non-firing 4th cylinder, I decided to pull the carbs again and really dig into them to make sure there was nothing blocking fuel to the 4th cylinder. I tore down and cleaned the carbs again. While the jets and stuff were soaking in carb cleaner, I decided to run cleaner through the fuel rail. Well it turns out there was some major blockage and corrosion in the rail between carb 3 and 4. I let it soak and tried to blow it out, but wasn't having much luck. These replacement carbs I bought to replace the original set that I screwed up were in pretty bad shape all around it seems.

So I'm getting frustrated and decide to pull out the old carbs that I had stripped the air mixture screw threads on to see if maybe I can swap out the fuel rail or something. Then I notice that the new air mixture screw that came in a rebuild kit was NOT the same as the ones I was pulling out of the carbs to clean. I go and grab a air screw out of the carb cleaner and it SCREWS RIGHT IN to the original carbs! Turns out that I didn't mess up the threads on the original carbs, I was just using the wrong f-ing screw!!!

Normally I would feel like a moron for all this, but I'm so stoked that my original clean carbs are operational that I don't care and I'm just stoked!:laugh:

Since I had the carbs off and apart, I shimmed the needles to help with the lean mid-throttle it was experiencing. I put it all back together and it fires up and runs like a champ (kinda) on all 4 cylinders! :laugh:

I take it around the block and it runs pretty good, well at least way better than it ever has before! The only things that I'm finding is that

a) there is a lot of popping when I release the throttle in gear

b) it sounds like it backfires when I shift

c) once it warms up the engine doesn't want to come down to idle. I have to disengage the clutch some with the bike in 1st gear to "pull" the engine back down to idle when I come to a stop. At that point, it seems to idle just fine.

I haven't had time to make any adjustments to the air screws on these carbs, but that's my next move. Do you guys have any other tips for the above ailments?

Thanks again for the help so far and thanks in advance for any more advice,

gintree

Problems sound like an air leak somewhere. Carb boots, orings, etc...

cool, I'll check those out. I thought my boots looked OK, but from some of the other posts on here, it looks like it can be hard to diagnose or see little hairline cracks, bad seals, etc.

wg - When you say orings, are you talking about all the little o-rings on the carbs that come in carb rebuild kits?