WARNING!! 550 Main jets

[REDDY]

I am currently trying to get an 80' model 550 L to run right. I have everything according to the manual. I am convinced the book is is dangerously wrong about the main jet size. From 7 k to redline it will hardly run at all. If anyone has experience with 550's carbs I would like to hear what works. I posted this on the CARB SPECS thread also. Would a air leak at the top of the airbox lean it out this much?

[brveagle]

how do your plugs look??

any mods?

stock intake/filter?

airbox lid on?

[Tarbash 27]

I just struggled getting my 550 to run. I ended up geting some new used intake boots and new o rings. Definately make sure the float height is to spec and the carbs are perfectly clean. I had problems with cleaning the pilots because there stuck in the carbs. But It runs fine now after taking the carbs on and off like 5 times.

[REDDY]

I have new intake boots and o- rings. These are the cleanest carbs on the planet. The plugs are white after plug chop. There no intake leaks that I can find. The floats were set by fuel level. All new o-rings. Everything is stock as far as I can see. I am at my wits end (short distance). If this has anything to do with the carb fairies, I will , with great glee, KILL! the first little SOB I see. As to removing and replacing these bastages (nine times), I am becoming far too proficient to suit me.

Seriously, does anyone have 92.5's (main jets) in carbs that are working properly?

[first timer]

i did for a little while, and it wasn't easy but evently they kind of worked out, yes i thing the 550 w/ cv's runs a tad lean. I think the 550 is prone to carb fairy infestation. I ended up going with a jet kit and k and n 550 pods. which helped but is still very touchy. I could ride the bike all season and it's fine (except i need to clean the filters every 2000 miles or they get to dirty and then i get some flat spots. but thats a story for another day.) but if i pull the carbs and not change a thing just spray them out they will go out of wack and the fairies come back.

What i have found that has worked pretty good for me is to turn out the air/fuel mix screw, try turning it to 2.5 maybe 3, i think 5 is max, see if that helps. You can also try to shim the stock needles up (put them under the c clip to raise and richen) go to radio shack and find the tiny washers they have. try that see if it helps the mid range. if you are still having issues, put needles back to stock and try steeping up to 95 mains or 1 size bigger. see if that helps.

so try the fuel mix screw first see how that works, no results, put back to about 2. then try shimming the needles, see how that works. no good results back to oem, then try the mains, no good results back to oem. then try the the needles shimmed with bigger jets. basically you need to try each thing methodically so you can eliminate what doesn't work. also make sure the carbs are synced at least once during this process, that will make a difference too.

-ryan

[REDDY]

Thanks for the suggestions. My main concern is THIS bike but I think SUZUKI leaned the 550 out as far as they could get away with because of fuel mileage and possibly EPA. There are Probably some people out there who have burnt their engine up thinking " if its stock it must be good ". I have 4 sets of carbs and only one set had 92.5's and it looks almost new. I am wondering if the number of used carbs is an indication of a "model specific" problem. The rest have 110's or 115's and I suspect they had the same problem as I do. If this is the case, it might be good to change, or at least put a warning in the carb specs thread about this. There doesn't seem to be a lot of info on this because most people don't know what size their jets are or even how their engine is running.

[Dave8338]

If you're having problems and think that you've done everything by the book, try this link. It is the best way to ensure that all the guess work has been removed.

http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html

[Road_Clam]

I am currently trying to get an 80' model 550 L to run right. I have everything according to the manual. I am convinced the book is is dangerously wrong about the main jet size. From 7 k to redline it will hardly run at all. If anyone has experience with 550's carbs I would like to hear what works. I posted this on the CARB SPECS thread also. Would a air leak at the top of the airbox lean it out this much?

Can you better explain ""hardly run at all" after 7000 rpm's. If your bike is completely stock, including stock main jet size, you bike should be correctly jetted. Do you have a vaccume operated petcock? (they are prone to malfunctioning). Do you have rust in the tank? (you could be getting "sediment blockage" inside the fuel tank). The internal fuel screen gets clogged with rust sediment, choking off fuel flow). You also might have a rusted fuel cap, which causes the vent to not function properly, which also chokes off fuel flow.

[Nerobro]

My bike ran on 92.5's for the first 20 years of it's life. :-) The plugs were slightly white, but that didn't seem to be a problem.

However, without the airbox on it, it wouldn't run very well at all. Are the boots going to the airbox ok? and define a "slight airbox leak" :-) ARe you talking a completely missing airfilter? or a 1/16" drilled hole.