Low vacuum readings in carb sync

There are nine different ways to measure vacuum.
24cmhg = 9.4 inhg.I have new 10.5-1 pistons and
300 duration cams.1100 rpm is about as slow as it
will idle so I set them at about 10 inhg.If you
have a bad cylinder the gauge needle will probably
jump around alot.

why are you wanting to pull the head? check the cams and the valves, run a quick compression check.
just a thought, did you make sure all the gauges are reading equal, hook all of them to one source and see if they read the same

just did the sync on my 650, my reading were right around 10.5 in at 1500 rpms. i really do not know if the gauges are accurate and really do not care as long as they are even.

I also sync'd mine to about 10 on the guages.

Alrighty thennnn! I meant the cylinder head to check the valve clearance and cams.. My bad.. Well, it looks like #2 and #4 @ 12 inhg(i think) look pretty good.. I'll try and match #1 that's @ 5 inhg and #3 that's @ 10 inhg to 2 and 4 and see how I come out.. Ahhh.. Closer and closer. It has been 8 long years since I've ridden my bike.. Owned it for 17 years.. I took it for a spin and man.... Do I miss it! I can't ride it back from Indiana until I get it safe and reliable though, so it seem like it's takin FOREVER.. Soon my pretty, soon..:blink:

flht1997 wrote:

just did the sync on my 650, my reading were right around 10.5 in at 1500 rpms. i really do not know if the gauges are accurate and really do not care as long as they are even.

aint no way its gonna run right with those H!#$@da gauges

hey! those buggers were .99 on ebay and i could pick them up so no shipping, and the work real good on a kawi.

Thes are the ones I just bought from ebay.. vgauge1.jpg[img size=500]

I don't know how to post 2 pics at the same time..:pinch: This is a closeup of under 10 inhg..