Carb Sync - no reading at idle

hexec · Sep 26, 2010

I have the Carb sync pro and cannot get it to read a vacuum from any carb. I've installed the dampers exactly as noted in the instructions. When I blip the throttle it begins to read then drops down to zero again at idle. This seems like a fairly easy process but I must be missing something because the tools instructions indicate not to sync based on higher rpms. The vmax manual is calling for 170mm Hg at idle.

I followed this thread http://www.vmaxforum.net/showthread.php?t=3959

Note, still can't get the pilot screws to make any sort of difference. I feel like I'm stuck between issues. I want to sync my carbs first to be able to troubleshoot an idle circuit issue. Any suggestions would be greatly appreciated.

PATMAX · Sep 26, 2010

It sounds almost impossible to not get any reading on any carb. Sounds like like yo made up your dampers right. I know it's a stupid question but the lines are on the right spot right? Maybe a picture would help us trouble shoot? I'm at a loss on this one!

65fury · Sep 26, 2010

This might be a stupid question... but did you hook all 4 carb sync hoses to the master carb first? This will make it so all 4 tubes will be drawing from the master carb. Then you set the screws on the carb sync tool to get all the fluid levels reading the same level......... just a thought. after that is done then you hook them up toall four carbs and sync from there.

Just for kicks try pulling a restrictor from a vaccum hose and see if it starts to draw fluid that way... be careful cause it can suck the fluid right outa the gauge, so keep your hand on the kill switch.

Jason

hexec · Sep 26, 2010

Ok, I've got the carbs sync'd but I had to use the choke to keep the bike running at just above idle. I double and triple checked the sync and I'm very comfortable with the adjustment. BTW, I first did a visual sync of the values to make sure I'm in the ball park then I did the fine tuning with the gauge. All went well with the exception of the idle circuit.

hexec · Sep 26, 2010

65fury said:
This might be a stupid question... but did you hook all 4 carb sync hoses to the master carb first? This will make it so all 4 tubes will be drawing from the master carb. Then you set the screws on the carb sync tool to get all the fluid levels reading the same level......... just a thought. after that is done then you hook them up toall four carbs and sync from there.

Just for kicks try pulling a restrictor from a vaccum hose and see if it starts to draw fluid that way... be careful cause it can suck the fluid right outa the gauge, so keep your hand on the kill switch.

Jason

I have the carbsync pro which doesn't use fluid. There are metal rods. Yes, I connected every hose. Not sure why it doesn't draw the rods up when the choke is not used. Again, I have to crack the choke ever so slightly to get a calm idle.