hey guys just picked up a 96 f3 and the idle won't stay. sometimes it stays but most of the time it will slowly drop untul it stalls out. i can keep it from stalling out by revving it but don't know the problem. carberateurs are clean so i have no idea. any suggestions?

 

Could be any number of things, but I'd check the plugs 1st, have a look at them to see wot sort of condition their in. Good indicator for your carbs. Tan around electrode is good, dark sooty colour can mean an over rich mix or badly synced carbs, Black & oily may mean your up for a set of rings, (although not typical unless the bike has done heaps of miles or been badly negleted), white deposits can mean plugs are old or wrong heat range.

A lot of guys who are going to sell their bikes usually don't worry to much about servicing them before they do & bike shops don't worry to much about em either (cept maybe make them look pretty). So plugs could may be just old and replacement may fix the problem, but at least by looking at them is a good starting point. Also check your air filter, A blocked, dirty air filter combined with an after market can, may cause this as well.

 

sounds like a vacuum leak.

 

what about turning the idle up?

 

I was thinking the same thing...

 

that depends on what the idle is set at when it DOES idle. if it is around 1250 then turning the idle up is just wasting gas. Something is definitely wrong with the bike.

In my experience (which I will admit is more car based than bike when it comes to engines) a vacuum leak will allow the engine to run under throttle but when it attempts to settle to idle the lack of vacuum caused by the leak will cause the engine to stall. This is especially true in old bikes like ours where the petcock is vacuum operated.

 

it only seems to happen when i am stunting with it. i rode it on the street and it idles fine. we have the idle set at 2500 and when it stalls it starts dropping real slow and it only happens sometimes. not that big of a deal just wondering what it might be. thanks for all the replies.

 

It honestly sounds like you're running out of gas. Once the fuel level in the carb float bowls drops below a certain line, not enough gas is getting to the engine and it begins to slow down and not as receptive to throttle. When it does stall, once you crank it back up again and run it for about 10-20 seconds does it run fine again?

 

it will shut off and i just start it back up. i don't think i am getting it high enough for it to do that because i can't get it to the balance point yet. not a huge deal though still fun to mess around with.