Re: hard starting when cold

[lrburke]

Hey Guys, this is just a new discovery since my post yesterday! I went out this morning and tried to start this GS550 again. I full choked it and cranked the heck out of it but nothing. I pulled one of the plugs out and it was absolutely dry as a bone. So now I know the reason for the hard starting! The choke isn't supplying enough fuel. What could be the reason or reasons for this? I know for a fact that all 4 of the starter jet tubes are clear and so are the passage ways in the float bowls. I actually have another set of rebuilt carbs on the shelf that I might try. Any suggestions would be awesome!

[hampshirehog]

No necessarily what you think. Could be a dodgy petcock, sticking floats, wrong valve clearances amongst other things. There are no short cuts to getting these bikes set up. If you follow everything on Basscliff's welcome you'll get the thing sorted properly.

[Nessism]

Yup, no short cuts. Basic maintenance includes: rebuilding the carbs with fresh O-rings, new intake boot O-rings, adjust the valves, etc. Build a sold base if you want to reduce the tenancy toward break downs.

[azr]

Just a thought, and only due to my personal experience, is there gas??

[lrburke]

Ha Ha! I have a clear fuel line and the carbs are full of gas. Could the float height cause it?

[azr]

Ha Ha! I have a clear fuel line and the carbs are full of gas. Could the float height cause it?

I suppose, but they would have to be very 'out'. There's really not that many reasons for fuel not getting to the cylinders. No fuel reaching the carbs (clear fuel line shows it is, so not a petcock problem or out of fuel). Plugged carbs (you've cleaned them and are sure they are clear, although it's funny with these carbs, sometimes 3rd time around gets them right, but not usually for no fuel to the plugs only for a bad throttle response) Floats wayyyyy out of adjustment (the very best way is to adjust with a clear hose from the bowl drain screw, but measuring does work as well), float needles stuck closed (try tapping the float bowl covers to unstick). Are all four dry as a bone? if you have another rack go over those with a fine tooth comb and throw them in, who know. Check the simple things first though, again due to my own experience, it's amazing how many times a lot of work is done only to find out it was the simplest thing to begin with! best of luck, let us know what you find.

[lrburke]

I just got finished removing the carbs again, checked every starter orifice(even the passage in the float bowl) pilot jets etc! Could find nothing blocked. I raised the float levels about 1 mm just for ****s and giggles! Bike started up after but it was a little warm from running it a little earlier. Won't know until tomorrow morning I guess!

[Nessism]

I just got finished removing the carbs again, checked every starter orifice(even the passage in the float bowl) pilot jets etc! Could find nothing blocked. I raised the float levels about 1 mm just for ****s and giggles! Bike started up after but it was a little warm from running it a little earlier. Won't know until tomorrow morning I guess!

Have you ever replaced the O-rings in the carbs and adjusted the valves?

[tom203]

Well, you are making progress! Some folks might have missed your previous post where you said it ran well once warm- idled well, etc... It has to be the enrichment system ( " choke" ). With a closed throttle, cranking engine vacuum should pull up enough fuel thru the tiny tubes- you say they are clear- did you blow air or gumout thru them? Doublecheck "choke" cable at carbs to make sure jets are all sliding open.

[Steve]

The choke isn't supplying enough fuel. What could be the reason or reasons for this? I know for a fact that all 4 of the starter jet tubes are clear and so are the passage ways in the float bowls.

OK, so you know that the passages in the bowls are clear, how about the ones in the carb bodies?

Please remember that "cleaning the carbs" involves a LOT more than just dropping the bowls and spritzing some cleaner around.

.

[lrburke]

Hey again guys, I have rebuilt a lot of Suzuki carbs and have had nothing but great results. That's why this one stumps me so badly! I separate all four carbs from the rails and soak each one in heated solution. I then use 1 can of spray cleaner on each carb to verify everything is clear i.e. pilot passages, bypass ports, starter passages and air jet passages. I then get all my o-rings from Robert Barr and reassemble. I also always replace the intake o-rings when applicable. As far as the float bowls I only soak the #2 and 3 because of the coating on the 1 and 4 bowls. I make sure that all the starter passages shoot a healthy stream out before calling them really clean. I put 4 brand new float valves from Suzuki in as well. All 4 of the choke plungers are opening all the way and closing really smooth. I will try to start it tomorrow morning and see if I helped anything this morning.

[Steve]

OK, thanks for the details. I have not seen any of your posts to note how well you do the carbs, it's just that too many think they can do a short cut.
Well, you know the rest of the story, because you know how to do it right.

One of your posts said you "raised the float levels 1 mm". Did you do that by setting them to a smaller number?
Remember, you are working upside down when you set the float levels.

I think it has been asked, I don't remember seeing an answer, ... have you checked the valve clearances?

.

[lrburke]

I did in fact set the floats to a smaller number which raises the level of fuel in the bowl. I set them to 21.4 instead of 22.4 like the factory manual says. I use digital calipers to do this. I have not checked the valve clearances as of yet since the bike carries 140 psi of compressioin across the board when cold. I can't imagine a tight valve would yield that kind of number. I will also do a leakdown test eventually which is my favorite test!! I am thinking about putting the set of carbs I have from a GS750 on there just to see if the choke works any better. The bike they came from was easy to start! It would kick right on fast idle. Thanks for your interest!

[crazy canuck]

fuel lines?

My bike developed the same problem a few days ago. Really hard to start in the mornings . I cranked it over this morning for 3 or 4 minutes with no luck. So when I got home from work , of to the garage I go. From my experiences an engine needs two elements to fire. Spark and fuel. After checking to see I had good spark at the plug ,which I had, it was obviously a fuel problem. First on the list was the petcock. I stuck a new hose on and sucked on it to see if I could get a flow of fuel going and noticed how hard it was to actually get some fuel from the tank with suction. After inspecting my line to the carb I noticed the end was split a little bit where it goes onto the petcock and wasn't all that tight where it connected to the carbs. Replaced it all with new line and clamps and the bike fired right up.It's very important that the fuel line has a good seal on the fittings. Hope it's nothing major..Good luck

[lrburke]

thanks for the reply! I do have a clear fuel line on the bike and it is definitely full when I am trying to start it however that is a good point about the vacuum line between the petcock and the carb! Mine really isn't that tight on the carb come to think of it! I will sure that up! It could be sucking a little air there I guess.