Weird idle issue

[CorradoG60]

Well I got my 81 finally running earlier in the week. But some issue with the idle at times. The motor is stock, I rebuild the carbs and cleaned them out and put pods on. I know I have to re jet them for the filters and the straight pipes I put on. The bike will sit at idle and idle fine then start to rev on its own really high. Sometimes crack the throttle and let go then goes back to idle. When my buddy rode the bike it'll rev again, squeeze the clutch, let go and idle down. I think I may have and air leak coming from the carb holders. I don't know. I have to get some carb cleaner from work and spray around to find something. I started it up the other day and went right to a high idle. Anyone have this happen?

 

[tx650]

It sounds like U may have a fuel supply problem.
Some of them are caused by a blocked vent in the fuel cap
needle and seat sticking
partially blocked in line filters
The filter above the petcock that is in the tank
Incorrect air filter
Air leak from carb manifold
There is more

 

[CorradoG60]

I just let it idle for some time and waited until the idle started to rise. Shut it down and put it in the garage. I could hear gurgling coming from the gas cap when I was pushing it in. I know when my brother had his harley at work he tried to start his and fuel was pissing outta the carb from the gas cap vent being blocked. The flow throught the inline filter is good. I have no in tank filter. I was thinking the needle may be sticking. Here is a pic of the tank and petchicken and the filters.

You can kinda see the filters here. They are the right size.

 

[CorradoG60]

Well I ruled the gas cap out. Kicked it over, took the gas cap off all the way. The engine got hot and then the rpms just climbed. I ordered new jets last night. So I guess I'll have to see when I get those in.

 

[weekendrider]

You have a vacuum leak. Not a case of a blocked gas cap vent.
IF the vent was blocked it would create a suction, not pressure
A simple anology would be fill a milk carton with water. Poke a small hole in the bottom.
Now when you put the cap on does the flow slow or increase?

If you haven't modified those particular filters they cause problems with stock carbs.

With all this idling do you have a fan on the motor? They are air cooled.

 

[5twins]

The way that throttle cable is routed, it wouldn't surprise me if that's hanging up too. Tie it in a knot why don't you, lol.

 

[CorradoG60]

You have a vacuum leak. Not a case of a blocked gas cap vent.
IF the vent was blocked it would create a suction, not pressure
A simple anology would be fill a milk carton with water. Poke a small hole in the bottom.
Now when you put the cap on does the flow slow or increase?

If you haven't modified those particular filters they cause problems with stock carbs.

With all this idling do you have a fan on the motor? They are air cooled.

I know what the blocked gas cap does from seeing it happen to my brother's harley. Gas everywhere out of the carbs. Until you open the cap and release the pressure. It pops like a SOB even cold.....running very lean. I totally forgot about the fan.

The way that throttle cable is routed, it wouldn't surprise me if that's hanging up too. Tie it in a knot why don't you, lol.

The throttle cable moves back and forth very smoothly and isn't binding at all.

I just have to wait til Thursday when the new main and idle jets arrive

 

[CorradoG60]

All set, jets came today and threw em in. Problem solved. Thanks guys