I can't find my starter jet "85" GS 550 ES

[Anonymous]

My service manual shows a #55 starter jet. It appears, in the picture, it should be in the bottom of the float bowl. The only thing I can see in the bottom of the bowl, is the pocket for the starter pipe to go down into. There is a very small hole in the bottom of the starter pipe, about the size of a bristle from a paint brush. Is this small hole in the bottom of this starter pipe, what they call a starter jet, or is there an actual jet somewhere that I'm not seeing.

[Anonymous]

If you have those oddball two barrel carbs, it is as follows (if what you call a starter jet is the same as the low speed jet)

holding the carb upside down, this is what you should see:


O o o O



the two outside "O"s are the main jets, the two inside "o"s are the low speed jets, the are down a short way inside those stems. The thing that has the hole about the size of a paintbrush bristle , i think , is an overflow in case the carb should over fill with fuel.

[Anonymous]

no, Those little ones in the center are the pilots #37.5, the big ones on the outsides are the mains # 90 for the 1 & 4 cyl & # 97.5 for the 2 & 3 cyl. Still looking for those dang starter jets

[Anonymous]

Hmmmmm..... Well, I just took another look at my carb blow up, and i don't see anything that is labeled a "starter jet". Then again, it is a Clymer manual, and if you have a factory manual, terminology will be different. There are also four pilot air jets in the back side of the throat (the side that mounts to the intake manifold). On mine, those are labeled 50.....maybe those are what you are looking for?

[KennyJ]

I believe the "starter jet" is actually the whole tube you are seeing. Isn't it brass instead of aluminum? It has been a couple of years since mine were off, but they will be off in a couple of weeks. You could probably remove the tube, but I wouldn't.

Kenny
85 GS550E
85 FJ1100

[KEITH KRAUSE]

The starter jet is inside and at the tip of the starter pipe. This regulates the fuel for the choke circuit. The starter pipe should be a small brass tube. That small hole you're looking at is the starter jet itself. They can be cleaned out with carb spray and compressed air. Is there a problem with yours?

[Anonymous]

Bike won't even try to start, when below 30 degree. Have tried to clean these little holes, without removing the carbs, then saw these starter jets listed and thought I might be missing something. I saw the little hole in the bottom of that tube & it looked like it would be close to a # 55. I'm thinking about drilling it to a # 57 1/2. If I mess it up, how much trouble will the whole tube be to replace, are they just pressed in?

[KEITH KRAUSE]

Bike won't even try to start, when below 30 degree. Have tried to clean these little holes, without removing the carbs, then saw these starter jets listed and thought I might be missing something. I saw the little hole in the bottom of that tube & it looked like it would be close to a # 55. I'm thinking about drilling it to a # 57 1/2. If I mess it up, how much trouble will the whole tube be to replace, are they just pressed in?

I would'nt drill it. The size of the starter jet is not the cause of your problem. I'm sure the carbs are designed well enough. The only way it could be the starter jets/starter pipes is if they're dirty. You have to take the carbs off the bike and spray carb cleaner in there and then blow it out with compressed air. You'll be able to feel the air come through if it's clear.
Clean out the entire choke circuit the same way. Make sure it's operating right. You can only do a good job and verify the circuits are clear with the carbs off.
Does the bike run well otherwise? Any mod's? What color are your plugs?

[Anonymous]

Bike runs great, after it warms up for 5 or 10 minutes. I've seen cold natured bikes before, but this one is rediculus. I'm dreading pulling the carbs, but can see it coming. I used one of those little straws on a can of carb cleaner to spray up thru thie starter jet, hoping I may get lucky, but of course couldn't see if I was doing any good. I guess it was a lot to ask for. Years ago we would put in a size larger pilot jet to get them to start easier, I may just try that. All stock, no mods of any kind. Only plug readings were after riding for a while with engine up to normal temps. Plugs look good, kind of a paper sack color

[KEITH KRAUSE]

I would'nt try to compensate for what sounds like a choke circuit problem, by making changes to the pilot circuit. Two different circuits, operating at different points. The starter circuit, if operating right, will start your bike with the throttle FULLY CLOSED. The pilot circuit is by-passed when you pull up the choke. For cold starting purposes, increasing the pilot jet won't have an effect at closed throttle. Increasing the pilot jet will only make the bike run richer than it should at lower speeds. Then you'll have two problems.
The real fix in this case is taking the carbs off and properly servicing them.

[Anonymous]

Are you sure the idle (pilot) circuit is turned off when choke is on? my understanding is that the starter (choke) circuit "enrichens" the idle circuit by adding a little more fuel to the normal idle mixture. The GS's of the 80"s were known for being cold natured, reason being epa standards for that time. Maybe it was all in our imagination, but everyone around here would put in a size larger pilots to help solve the aggrivation of being so cold natured. It made a noticable difference in the starting & warm-up time. I never remember anyone saying they could not tell a big improvement. I never knew anyone who had one of these 4 cyl. 2 carb 550's, but have heard rumors that they were the cold naturedest of all the GS's. Thought it may be kind of normal not to want to start in cold weather, but maybe they aren't that bad. Maybe someone who owns one of these rascals will tell us how cold natured these things really are. Who knows, maybe a good tear down & cleaning will do the trick, but I do dread getting in to it. Thanks

[KEITH KRAUSE]

I can see what you're saying. The way the carbs are designed, it's the starter circuit that actually gets the motor started. By-passed was not the right word to use since the two circuits do work together.
As the motor cranks with the choke opened and throttle closed, negative pressure will build up at the smallest jet, the starter jet. This extra rich mixture helps cold combustion. Initially it's the starter circuit that delivers fuel, but as you said, the starter circuit is still an aid to the pilot circuit.
I can also see where a larger pilot jet would help warm up the motor faster, which would help a cold-blooded motor. But the richer pilot circuit will make the motor run richer all the time, which is'nt good.
I just think a larger pilot jet as compensation for a partially blocked starter circuit, is not the best fix. The best fix, with no consequences, is to clean the choke circuit so it works like it's supposed to.
If there's a possibility that this model's carbs were inadequate, then you would have no choice. We've all seen poorly designed parts before.

[KennyJ]

OK, from a 19 year owner of a 1985 GS550EF I know a few things about the bike, and regretfully, about the carbs.

The 550 is the coldest blooded bike I have ever had the pleasure of riding. I usually ride from spring late into the fall in Spokane WA (temps below freezing). In the heat of summer, the bike still needs the enricher circuit to start, and has to run it for a minute or two until it can maintain idle. On the coldest mornings, it can easily be 10 minutes before it can run without the circuit. It is one of the few quircks about the bike.

As for the circuit, it actually draws its own air through the CV chamber. If you look closely, the switch/cable controls a small slide and needle assembly (not really a needle per se, but does stop/reduce fuel flow). The air for the circuit totally bypasses the butterflys and carb throats.

I would venture to guess that the pilot jet does have a small effect on cold running, but with the circuit fully on (open) the effect is probably nill, and with it almost off (closed) it has a major effect.

Just my .02
Kenny