Why does idle speed increase as engine warms up?

[Adam E.]

Hello everyone,

First I have to say it's great there is a forum dedicated to the old wings. I have been a regular at WOTI for a while now but they seem to be much more interested in the new ones.

Here is my problem. I have a 1978 GL1000 and for some reason every time I ride it the idle speed increases from around 1000rpm to as high as 2300rpm when the engine has warmed up. I can't for the life of me figure out why this is happening.

Anyone out there have any ideas about what could be wrong or what I should look for?

Thanks, in advance, for any assistance.

Ride safe.

[BIG T]

hey adam,
the problem may be a vacuum leak between two metal to metal surfaces such as,intake elbow to head surface,even though they have o ring seals.
or.....it could be that the exhaust to head connections need to be retorqued to factory spec. if you can, run it up to temp., then pull the plugs,one at a time, look for a lean burn . if one plug,it's on the intake side of the flow,if all are the same, try the exhaust retorque.(recomend penetrating oil at least 24 hrs. before tighting).
good luck................"T"

[Adam E.]

Hi T,

Thanks for the help. I will take a look and see what I find. I'll post my findings later.

Adam

[Try]

Hello everyone,

First I have to say it's great there is a forum dedicated to the old wings. I have been a regular at WOTI for a while now but they seem to be much more interested in the new ones.

Welcome to our message boards Adam.

Here is my problem. I have a 1978 GL1000 and for some reason every time I ride it the idle speed increases from around 1000rpm to as high as 2300rpm when the engine has warmed up. I can't for the life of me figure out why this is happening.

Anyone out there have any ideas about what could be wrong or what I should look for?.

It can be:

Overheating
The ignition timing may be set wrong
a vacuum leak
The alternator may not be working properly
you could be looking at a sticky/dirty throttle
plate or a misadjusted throttle stop screw or throttle cable

A way to test for intake leaks is to spray flammable brake cleaner
onto the suspected parts. If the idle changes when you do this
- goes up or comes down- then there's your leak.

Check each of carb slides to be sure they are all dropping down