1991 ST1100 Honda with 21k miles. Starts throttle kills engine. Turning choke off ki

1991 ST1100 Honda with 21k miles. Starts and using throttle kills engine. Turning choke off kills engine.

I need some help. Juddspaintballs helped redo the carbs a few years ago and bike ran fine. bike has 21k and is in great shape otherwise.

My prob is it starts on choke but does not idle high on choke like it used to, maybe 2k rpm.
If i give it throttle it dies. If I turn choke off (even with warm engine) it dies.

I have lots of fuel before and after the fuel filter and i dont know what to do. its been running crappy for awhile. My cell is 2028703214. Can you help me....

Craig, now in Wilmington NC

Re: 1991 ST1100 Honda with 21k miles. Starts throttle kills engine. Turning choke of

Clogged jets.
You'll have to either run a *whole* lot of seafoam/techron through or you'll have to pull the carbs and clean the jets manually.

Re: 1991 ST1100 Honda with 21k miles. Starts throttle kills engine. Turning choke of

Craig_st1100 said:

1991 ST1100 Honda with 21k miles. Starts and using throttle kills engine. Turning choke off kills engine.

I need some help. Juddspaintballs helped redo the carbs a few years ago and bike ran fine. bike has 21k and is in great shape otherwise.

My prob is it starts on choke but does not idle high on choke like it used to, maybe 2k rpm.
If i give it throttle it dies. If I turn choke off (even with warm engine) it dies.

I have lots of fuel before and after the fuel filter and i dont know what to do. its been running crappy for awhile. My cell is 2028703214. Can you help me....

Craig, now in Wilmington NC

Click to expand...

I suggest pulling the left Tupperware cover over the valve cover and check that the hold-down clamp for cable housing hasn't come loose. If that housing hold-down comes loose, the cable housing will slip and move instead of the cable itself working the choke. I just know this as I had it happen on my 92ST, giving the same scenario your having.

Re: 1991 ST1100 Honda with 21k miles. Starts throttle kills engine. Turning choke of

i pulled stuff off to see the choke cable and it is moving like it should. Accelerator cable is also working as it should. If the carbs are the only answer i will run some seafoam and pray

Re: 1991 ST1100 Honda with 21k miles. Starts throttle kills engine. Turning choke of

Just a thought...be sure your idle adjustment cable is secure and the setting should be 1100 rpm and yea, run some Seafoam or Techron. HTH

Re: 1991 ST1100 Honda with 21k miles. Starts throttle kills engine. Turning choke of

If you have to pull the carbs, it's really no big deal. It's a little scary at first and they are really on there solid with the boots, but now having done it 3x (2 on the 2000, once for carb jet cleaning and once for the under carb hoses replacement as well as on the 94 for the hoses), it's pretty straightforward, just some work. Body wise, side covers, engine sides, tank shelter, and gray compartment panels all need to come off (so ~30 minutes). If the jets are really gunked up with varnish, Seafoam may not help. I used compressed air when I cleaned the jets on the 2000 (the idle jets) and I used a cheap air tank/ compressor combo and the needle valve you would use for inflating a basketball which fits the jets very well. If you have to go this route, get new carb boots (they're $8 each on Partzilla.com) and when reinstalling the carbs, use a little Wd-40 on the boots to get the carbs to slide back on (some don't like WD-40 for rubber, but use a minimal amount and it'll be fine). There's a lot of good info on this site on how to pop the carbs off (basically, loosen the clamps from the sides- little tough to see but once you see them, not too bad), then lever them off the boots. Some folks take the gas tank out...I never did. I used a tire iron in between the carb bank and the rubber where the gas filler is and just levered back and forth until they loosened enough to pop off. I would do the Seafoam or Regane, etc. to see if you can clean it that way. I just know in my case it didn't work and it was from the bike sitting unused for quite a while one year (back in 2008 I think). After it's all sorted, use a fuel stabilizer if the bike has to sit for a few months and be sure it gets run through the carbs as well.

Good luck.

P.S. If you have to yank the carbs, be sure to stuff the intake holes with a paper towel to keep foreign objects out of the intake and get a flexible magnetic pickup for the screws that invariably fall into the under the carb area- it's a VERY useful tool to have in the arsenal. Magnetic screwdrivers are a good idea as well.

Kind of late to the party here - but I had exactly the same symptoms with my '91 and the problem was the carb vent tube in the smog system was clogged. The solution was so simple - just unplug the vent tube and put an air cleaner on it. Done! I never went through the trouble of taking the whole smog assembly apart to find the actual problem. Obviously - that would be the right thing to do. There is a hub behind the radiator cap - next to the petcock where the smog tubes connect (at least I think this is all part of the smog system - I could be wrong?). It will be the one on the left. By the way - this was the dealer solution - not mine!

Pilot jets are plugged most likely. I don't know about that Seafoam stuff but it most likely will need a manual cleaning of the pilot jets.