rising idle

[villageidiot]

my idle is set to 1200 ish when cold, but when it gets hot it goes up to anywhere from 3 - 4000. it also seems to get hot quite quick.

im thinking theres an air leak in the carb rubbers somewhere causing it to run a bit lean, therefore hot.

am i guessing right? like to have a second opinion before i buy some new rubbers.
cheers
justin

[sailfish]

It sounds like your choke circuit isn't closing. Check the choke cable and linkage for it's full range of operation.

[Berniebikes]

When I had an open vacum hose my idle would rise like that to say 2000 to 2500 or so when the engine was warmed up, and then wander around a bit. Check your vacum hoses and connections.

[Dittos3]

start your bike cold and spray the carb rubbers with carb cleaner. If idle shoots up, then a hole (or holes) in the rubber let some of the cleaner through.

Ditto

[screene]

I have exactly the same problem since removing and reinstalling the carbs on my 91 Trident. I replaced the fuel lines while I was in there, but put the old vacuum line back on. (I re-routed one of my fuel lines to run round the back of the frame - it just seemed an easier way to do it.)

I will follow this post with interest.

[matt.speedtriple]

If you`ve not done any work on your bike then it certainly sounds like you`ve an air leak somewhere between your carbs and cylinder head and yes this would cause the bike to run lean and heat up far faster than normal.

If revs fluctuate after the carbs had been removed from the bike this will more than likely be sorted out by balancing the carbs.

Cheers, Matt

[villageidiot]

changed the rubbers either side of the carbs, one of the carb/airbox rubbers had been pinched slightly, and two of the carb/head rubbers were perished. also found that one of the vacuum cap/cover things had a small hole in it, which i have sealed for the time being until i get a new set.

seems to have done the trick, idle is still a wee bit lumpy so will get the carbs balanced which should sort that out.

justin