balancing carbs

[mortation]

Anyone have any tips on how to do this right? I am going to order a couple of different "adjusting" tools from motion pro when I get paid because the #2 adjuster nut is a major bitch to get to and I can never get it right.

Aside from the my motion pro "economy" tuner sucks. The damn mercury never stays still or at the same level. Would vacuum gauges be better?

[Nessism]

I bought that long handled Motion Pro tool and had to mod it by opening up the hole in the center of the socket - where the screwdriver pokes through - before it would sit down on the adjuster screw/nut. Even at that, the adjuster between #1 and #2 is blocked by the frame and hard to reach.

Regarding the mercury not staying still, it's true but all the columns should be moving more or less the same amount so just get them close. No need to split hairs and get them perfect, it doesn't matter. You are just looking to get them within 1 cm or so of each other. And don't forget to put a fan in front of the engine and check the sync at 2500 rpm or so - above idle.

Good luck.

[tkent02]

Just curious, about the fan...
How long do you guys run the engine trying to synch?
I run it less time than sitting at a red light, usually don't even bother hooking up the little gas can.
Certainly a couple minutes is enough?
Are you being perfectionists?

And if your mercury is bouncing too much, try a smaller restrictor in the lines...

[BassCliff]

Fancy tool vs. vacuum gauges

Hi Mr. mortation,

I went over to Mr. rapidray's house yesterday so that he could balance my carbs. I was a little surprised to see him pull out a set of 4 vacuum gauges. There were tubes with o-rings that screwed into the vacuum ports on the 4 intake boots. The vacuum lines from the gauges were connected to these tubes. The vacuum gauges bounced at idle but if you balance your carbs at about 2000rpm they are very stable. Didn't I read where you have to calibrate the Carbtune and MotionPro tools to the #3 carb? This wasn't necessary for the vacuum gauges. It took me longer to remove and replace the seat and tank than it did for Mr. rapidray to balance my carbs. Thanks Ray! :-D

I found out I am going to need new intake boots and O-rings. Not that there's any leaks, but a previous mechanic slammed a slightly larger phillips head screw in the #4 vacuum port instead of the correct size allen head bolt. I never noticed it until yesterday. Drat and bother. I might as well replace them all with fresh stuff while I'm in there.

Thank you for your indulgence,

BassCliff

[Nessism]

Just curious, about the fan...
How long do you guys run the engine trying to synch?
I run it less time than sitting at a red light, usually don't even bother hooking up the little gas can.
Certainly a couple minutes is enough?
Are you being perfectionists?

VM carb bikes are EASY to sync and only take a few minuets for me. CV carbs on the other hand are a real pain because the adjusters are hard to reach and tweaking one adjuster seems to effect the others sometimes. Plus, the idle needs to be set higher than normal - engine will heat up pretty fast.

You are right maybe about being too anal about getting the adjustment just right - no real benifit in this.

[tkent02]

VM carb bikes are EASY to sync and only take a few minuets for me. CV carbs on the other hand are a real pain because the adjusters are hard to reach and tweaking one adjuster seems to effect the others sometimes. Plus, the idle needs to be set higher than normal - engine will heat up pretty fast.

You are right maybe about being too anal about getting the adjustment just right - no real benifit in this.

I forgot about the CVs being more difficult, haven't synched them in a while. and when I did it was on a perfectly running bike.

[doctorgonzo]

My Carbtune comes out of the shrink wrap today. CV carbs, hope I can fumble my way through it.

[GSJohn]

I had to disconnect the throttle linkage to get at that middle adjuster. Then the problem is tightening the lock nuts without affecting sync. I am going to try to make a custom tool to tighten the lock nuts while holding the setting before I attempt to get mine better synced. It would also be nice if those vacuum port screws were aimed up instead of down!