Carb surging

[davidon]

When syncing carbs using Carbtune I'm finding one of the carbs is stable and then surges slightly which makes it hard to get an even reading. Can this be caused by a misfire or something else and how can misfires be corrected?

 

[maleko89]

I would check spark plug and the condition of the plug wire first. Then, clean the idle circuits of that carb. You mixture screw might need to be adjusted a tad.

 

[davidon]

By checking plug wire do you mean physical condition or is there a way to tell if a wire is suspect?

 

[shawn kloker]

I would check all the rubber boots first for loose or cracked then check the diaphram for holes or tears.If that looks good shot gun it or peashooter it.

 

[firefly]

are you adjusting per service manual instructions or just trying to get all carbs leveled?
read the service manual for proper synchronizing procedure.

When syncing carbs using Carbtune I'm finding one of the carbs is stable and then surges slightly which makes it hard to get an even reading. Can this be caused by a misfire or something else and how can misfires be corrected?

 

[mikemax04]

When syncing carbs using Carbtune I'm finding one of the carbs is stable and then surges slightly which makes it hard to get an even reading. Can this be caused by a misfire or something else and how can misfires be corrected?

Surging usually indicates a lean carb mixture which can be caused (as already stated) by either a mis-adjustment, partially clogged circuit or air leak after the carb. These carbs are very touchy and hard to keep perfectly in tune. If it idles OK and runs good, I wouldn't spend a whole lot of energy tearing into it (unless it's really noticeable by ear). Back out the idle mixture screw 1/2 turn. If that doesn't help, do what Shawn and Mark suggested. If in doubt of a procedure, ASK, that's what we're here for.

 

[maleko89]

To check plug wire, check continuity. You can also stick multimeter lead up in plug boot and ground the (-) lead. Should read 18.5 to 24 KOhms.

 

[davidon]

Did'nt mention these are flatslides so syncing procedure is different but the principals will be the same. Will try adjusting mixture screws and check for air leaks as these seem most likely. Also will check wires and resistance

 

[shawn kloker]

flatslides are totally different animals than cv carbs.

 

[Robbarrie]

Not sure if this applies to the Max, But I have a flatslide on my RM - these carbs don't have a air mixture screw. I wasn't aware that they had flats on a Max. My bike is a 93 and doesn't have flatslide carbs. This is not to say it is written in stone, its more that I was unaware.
P.S I took the damm thing off, these carbs just suck. Bike wouldn't idle at all (unless your rev are up around 3 ) so I put on a real carb, not as responsive as the flats. But flats are for racing anyways.