Won?t Start GS550T 😕

[Mr.humbucker]

It?s spring time and time to start riding again here in British Columbia. Today I tried to start my GS 550 T but had no luck, it would start, run, but when I went to take the choke off it would die. Trying to troubleshoot this on my amateur own I figured the carbs might be dirty as it?s been probably eight years since they?ve been cleaned. So I pulled the carbs and found that they were spotless. While I had them off I saw a few deficiencies namely One of the choke plunger seals, if that?s what you call them, was missing so I replaced it along with the O-rings that seal off the these plungers.

Unfortunately when I re-assembled and installed the rack I forgot to put on the idle screw. The bike started and ran great but again it wouldn?t run after I had taken the choke off. This was pretty easy to explain, at least in my mind, as by this time I figured out that the idle screw is missing. So, lucky me, I get to remove the carbs once again which for those that are familiar with the GS 550 this is a bit of a chore. Oddly enough I suppose there?s always a positive side of things I?m getting pretty good at taking them out and putting them back in again. So I remove them installed the idle screw and reinstalled them and probably did the best job I?ve done yet ensuring that all of the clamps on the boots were sealed properly.


This this time when I went to fire the bike up I didn?t seem to be getting any fuel into the system. I know I had spark and that the fuel was running into the carburetters but they didn?t seem to want to go past the float bowls and into carbs and the engine.

Any suggestions on what I may have missed would be appreciated.

[Big T]

You can't see the clogged passages
Clean your carbs per the tutorial

[BigD_83]

If stored with fuel in the carbs then there is a really good chance it is as BigT suggests...

I negligently forgot to run my 550 out of fuel when I parked it, thinking I would be riding more, but...you guessed it, it'll fire up and run, but only on #s 3 and 4. Time for a spring cleaning for me.

Strength in solidarity!

[Mr.humbucker]

I took the advice I was given and strip the carburetors down, Put them in my ultrasonic cleaner, Installed new O. rings on the air screws as the old ones were a bit dodgy. After Reinstalling the carbs I fired the bike up and she started with no problems whatsoever, however ... the revs were really really high. After giving it some thought I've come to the conclusion that I have the air screws set too high, I'd set them to the setting that I had recorded when I removed them for cleaning, upwards of 3.5 turns.

I will try again tomorrow and have the screws at two turns out from the bottom and see how it goes. Crossing my fingers thanks for your input!

[Nessism]

How long since you last changed the carb boot O-rings? The pilot screw setting won't cause the issue you mention.

[Mr.humbucker]

About 7 year or so ago I had new boots put on by a guy before I started doing my own maintenance. I have no recollection of whether or not they were changed then or not but I'd like to think they were. If after trying a few things today doesn't work I may take them off (yet again) to see what shape they're in. I am pretty sure I have a new set laying around here somewhere.

I am curious how the carb boot O ring seal here would be a problem now as prior to the initial removal of the carbs a few days back and the their cleaning/overhaul this high reving issue didn't exist. How/why would it come up all of a sudden? For what its worth all of the seal for the mount of the carbs is very tight/snug with with the clamps on on the intake boots and airbox.

[Mr.humbucker]

Ok ... some success and learning all at once .... �� I adjusted the pilot screws to two turns out and as outlined below by Nessism this had no impact. Next, after scratching my head for five minutes starring at the bike I realized that perhaps I had incorrectly adjusted the throttle cable too high where it brackets on to the carb rack. With this in mind I wound the cable screw (my term ... any experts that know the correct name for this feel free to tell what the proper name for it is) and tightened the locking screws. Next I attempted to start the bike and it fired up right away without the high revs! The next task is to likely adjust the throttle cable again as the bike revs too low once I ease off on the choke. With some luck I’ll have this all figured out and be out riding by September ��

[1978GS750E]

Adjust the throttle cable to the desired amount of "free play" that you want in the grip. Adjust the idle by the idle adjustment screw.

[Mr.humbucker]

All good now, took it in for a balancing at the local MC Repair shop GForce in Kamloops - Garth did a great job putting everything right and answered my questions on syncin/balancing the carbs.

Amazing to think the bike is 40 years old now. Bought the same model in 1981 new way back when 😁. My goal is to keep her on the road for the next ten years and hopefully be able to do a 50th anniversary ride.

Now on to the 83 850G ... I will take it in this week and get her on the road too. Spring is finally here and summer isn't far away. Lots of retirement riding on the agenda!

Thanks to all that provided input here.