ST1100 won't idle-Shame on me

curtspivey

curtspivey

Joined
Mar 11, 2008
Messages
83
Location
Nampa, Idaho
Bike
'09 1300
I must confess my sins among the brethren. The gas in my ST is about a year old. And it's been about that long since my wife and I have ridden. At first they wouldn't start unless you ran with the choke full on. And as much as I hated it I siphoned over 10 gallons of gas out of both bikes. Changed the fuel filters and put in new gas and they run fine. Problem is when you let off the throttle it drops below 500 rpm's and the engine dies. The idle "knob" is adjusted as far out as it will go.
I've never done a valve adjustment or carburetor balance/rebuild. So, this may be the root of the problem. Any other ideas?

BTW, Sorry we have been away so long
 
You should run some SeaFoam through your fuel system also as I am sure the old fuel gummed up your system. Give that a try and things should get better. Good luck!

:usflag1:
 
If the sea foam doesn't do it, you'll need to pull the carbs and clean the low-speed jets. Not that hard to do but it is time consuming.
 
I was considering pulling the carbs to deal with the dreaded antifreeze leak. I've never heard of "sea foam". I have run some regular STP fuel cleaner thru it.
 
curtspivey said:
I've never heard of "sea foam".
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SeaFoam.jpg
 
Sounds like plugged up pilot jets. Classic scenario of poor idle, otherwise runs well. Does a little choke make it idle?
 
curtspivey said:
Sounds a lot like Marvels Mystery Oil. Kind of a cure-all for what ales ya.
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Don't rag on MMO. The FAA approves it for use in aircraft piston engines. It sure doesn't hurt anything when used as directed. I only add it to the fuel, not the oil in wet clutch applications. I use it all my gasoline engines. I don't own any diesels or turbines.
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itsbent said:
Don't rag on MMO. The FAA approves it for use in aircraft piston engines. It sure doesn't hurt anything when used as directed. I only add it to the fuel, not the oil in wet clutch applications. I use it all my gasoline engines. I don't own any diesels or turbines.
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Nope, not picking on MMO. I actually bought a bottle of it when I drained the tanks. It's the first thing I put in the gas. Just hadn't heard of Sea Foam.
 
curtspivey said:
Nope, not picking on MMO. I actually bought a bottle of it when I drained the tanks. It's the first thing I put in the gas. Just hadn't heard of Sea Foam.
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I never heard of it either till I joined this forum. From what I read, it gets high marks. Just hope things don't get so bad that I need it.
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I am a firm believer in Sea Foam. I run it in my outboard motor, motorcycle and autos. In my experience Sea Foam is a better prevent-er, than immediate cleaner. Berryman's B12 Chemtool is stronger. you can pour it or spray on a varnished carb and watch the varnish run off. Best part it's about 1/3 the price of Sea Foam.

Ralph Sims
 
I have used both Seafoam and B-12 and agree with BuddingGeezer, especially with the part of being a firm believer.
If that doesn't clear it up, I would certainly follow George's advice.
Glad you're both back.
 
I think I'm going to go ahead and rebuild the carburetors. Any advice on a supplier for a rebuild kit? It would be a pain in the butt to try and order all the individual parts.
 
Based on your original post that bike runs fine, except won't idle, I wouldn't think you need any new parts. Maybe the bowl o-rings, maybe not. Again based on the OP the needle seats, floats and diaphragms sounds good. Pilot jets are what's stopped up.

Ralph Sims
 
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BuddingGeezer said:
I am a firm believer in Sea Foam. I run it in my outboard motor, motorcycle and autos. In my experience Sea Foam is a better prevent-er, than immediate cleaner. Berryman's B12 Chemtool is stronger. you can pour it or spray on a varnished carb and watch the varnish run off. Best part it's about 1/3 the price of Sea Foam.

Ralph Sims
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Agree on the sea foam is likely not that agressive in diluted form - how about pure form in a gummed up jet? Evidence to this would set an expectation for diluted in fuel 64:1.

What concentration on Berryman's is specified. Does it harm rubber fuel lines or plastic parts like the float bowl?

Does the Berrymans disolve fuel varnish in diluted form?

I think we should do an experiment - any one have some gummed carbs and a whole bunch of time to do a before / aft visual comparison at different concentrations.

Paul
 
Oldschool1 said:
Agree on the sea foam is likely not that agressive in diluted form - how about pure form in a gummed up jet? Evidence to this would set an expectation for diluted in fuel 64:1.

What concentration on Berryman's is specified. Does it harm rubber fuel lines or plastic parts like the float bowl?

Does the Berrymans disolve fuel varnish in diluted form?

I think we should do an experiment - any one have some gummed carbs and a whole bunch of time to do a before / aft visual comparison at different concentrations.

Paul
Click to expand...

I have filled carb bowls with SeaFoam prior to tear down. Did it help?? I do know that Seafoam doesn't disolve the varnish on the outside of carbs immediately like Berryman's does. Based on my experience with Berryman's, it would be better tham SeaFoam in that application. 1oz per gallon of fuel is dilution. Berryman's also comes in a spray can. Doesn't harm rubber or plastic and I guess it disolves varnish in a diluted form, it cleans the fuel system.

I think Seafoam may work better for carbon cutting. At least it is marketed as such and Berryman's only mention is "cleans intake valves". I'm not looking at a can of Seafoam, but Berryman's says not to use in diesel engines and I think Seafoam is diesel safe?? Again working from memory Seafoam is 1oz per gallon and 2oz per gallon in a really carboned engine, but an oil change is need after a tank at that dilution.

SeaFoam is also a good fuel stabilizer.

Ralph Sims
 
I've known folks running MMO in their high-time aircraft engines to prevent sticking valves. I knew an instructor when I was training for my private license who was running a high-time (TBO was 2000 hrs. and he was a good bit above that) Lycoming in his Piper Cherokee Archer II and he swore by it. He was putting it in the oil.
 
Regarding the carbon cutter w/ Sea Foam. I had a sprark plug out that was black with carbon (not thick just a black insulator and tip - so I dunked the tip in sea foam (undilluted) overnight and the next day the sea foarm was just as clear as when i poured it in the glass. The plug tip appeared to be unphased by the sea foam as it didn't scratch off any easier or look any different.

So unless sea foam removes carbon by creating expecptionally high combustion temperatures - I don't know of another mechanism it would rely upon for carbon removal.

If it does remove carbon by high temperatures I'm not sure what to think about that as high temps are usually an enemy of engine longevity - at least i'd want to know that the temp range is safe for the duration.

I've never seen anything on the Sea foam sight about the mechanism by which it accomplishes anything.

Thanks for the information I'm anxious to do some experimentation with Berryman's.




BuddingGeezer said:
I have filled carb bowls with SeaFoam prior to tear down. Did it help?? I do know that Seafoam doesn't disolve the varnish on the outside of carbs immediately like Berryman's does. Based on my experience with Berryman's, it would be better tham SeaFoam in that application. 1oz per gallon of fuel is dilution. Berryman's also comes in a spray can. Doesn't harm rubber or plastic and I guess it disolves varnish in a diluted form, it cleans the fuel system.

I think Seafoam may work better for carbon cutting. At least it is marketed as such and Berryman's only mention is "cleans intake valves". I'm not looking at a can of Seafoam, but Berryman's says not to use in diesel engines and I think Seafoam is diesel safe?? Again working from memory Seafoam is 1oz per gallon and 2oz per gallon in a really carboned engine, but an oil change is need after a tank at that dilution.

SeaFoam is also a good fuel stabilizer.

Ralph Sims
Click to expand...
 
My wifes ST won't idle or run unless I keep the choke full-on and keep spraying carb cleaner in it. So somthing is plugged up. My ST runs fine except it won't idle. I wonder if I can get to the problem without pulling the carbs? I'm sure I could do it but it looks like a pain in the butt.
 
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