Saimese carbies

[erjeff]

Don't think there are any electrical problems. The ignition and charging systems have always been OK and battery is in good shape. I started out with the pilot needles set at 2.5 turns out because that was the original setting when I removed them. I have since experimented with the adjustment but it doesn't seem to have any effect at all. The needles were in good shape and I did put new O-rings on them. New intake boot O-rings as well.

[Nessism]

Sounds like the pilot jets are plugged. Did you hold them up to the light when you had them out to make sure they were clear?

[erjeff]

Sure did. They were plugged up when I first removed them. They absolutely were open and clear when I reassembled things.

[Nessism]

No idea what could be wrong with the carbs. The igniters are a weak spot on those bikes. Did you check spark?

[erjeff]

Thanks for all the ideas everybody! If you think of anything else to check let me know.

I have the day off on Wed. so I'll probably pull the carbs again and see what I find. Just afraid that after all that I won't find anything. It should be interesting though.

[elrico]

siamese carbies

erjeff,lots of great offerings from the members to dwell upon and check out in your troubleshooting.Hope you can try them out,they may reveal an overlooked cause(s). I will say,having this carb set also to perhaps(up to you):Gently screw down all 4 pilot needle screws(too hard/tight,little o rings can break/split ).I tried best idle senarios etc.Found to my surprise(because it got good results,for bad idle/driveabilty),4.5 to 5 turns up from bottom was the charm to tame unruly dragon.Just another tale in the Siamese Twins story.Work/Ride Safe ,let us know what goes on.

[elrico]

erjeff,GSR community,social groups has GS550 group:has probably for certain crossed paths with the legendary Mikuni BSW30SS aka/Siamese/Carbies you have as possible current concern/project.

[gs550e]

I'm experiencing the same issue on my 83 gs550e. I cleaned the carbs and changed the jetting to correct service manual specs and now sometimes it will start no choke and clean. Then it dies out after going up the street and only starts on choke. Then it dies out for good and I usually kill the battery. I supplemented a gastank for diagnosis with good flow and a paper inline filter. Carb bowls are getting gas when drain plugs are pulled. And slow system on carb has been gone through. How bad is it to be one pilot screw oring short?. And do intake boot orings stick out from bolting surface or do they sit flush in the groove? Mine look to not be sealing.

[JEEPRUSTY]

they stick out a wee but

[erjeff]

Hey Guys, here's an update.

I pulled the carbs again and tore them down. Cleaned everything again and made absolutely sure that all passages were clear. I did discover that the main jets were reversed from the normal position. The 95's are supposed to be on the outboard cylinders and 102.5's on the inboard but they had been switched by the PO. I know it wasn't me because the first time I tore them down I made a scribe mark to be sure everything went back to its original spot. Not sure how much of a difference this would make though.

When I got the carbs re-installed she started up and ran great even with no choke. Synched them as best I could and went for a test drive. Ran better than ever but would still immediately stall when I'd let it idle at stops or in turns, although it would idle just fine when started up in neutral.

I then pulled the valve cover and adjusted the valves. Some of the exhaust valves were too tight and the intakes tended to be too loose. I also turned in the pilot screws a full turn (they had been 3 turns out) synched em again. Now it's running perfect!

[elrico]

.erjeff,celebrate that,taco dinner maybe?I feel your good feeling.

[Steve]

I then pulled the valve cover and adjusted the valves. Some of the exhaust valves were too tight and the intakes tended to be too loose.

Hopefully you let the engine cool COMPLETELY before adjusting the valves.

The manual calls for a COLD engine (not run for 8 hours) before checking clearances.

.

[erjeff]

I let it sit overnight before messing with the valves. Set them all so that a 0.10mm feeler would just slide in but a 0.12 wouldn't go.

[BassCliff]

Hi,

Thank you for reminding us that it's always a good idea to do all of the required maintenance in order to have a well-running motorcycle. Congratulations on your success!


Thank you for your indulgence,

BassCliff

[snicrep5]

wha..what?! whats all this talk about different size main jets on outer and inner carbs? Am i missing something. Admittedly I didnt read all the posts leading up to this one.