I've got one of the best vacume sync tools out there (Morgan made in england) that I use on bikes. I've used it to verify sync on sled carbs that I tuned "the old way", and found "the old way" to be spot on or close enough, so I don't even use it anymore. I do use it sometimes to to "see" the effect of an intake mod.

The old way= set the slides the same on the idle stops gauging them with a drill bit. rig the throttle wide open and adjust the slides flush with the top of the throttle bore. If any adjustment needs to made for cable freeplay I simply count the amount of turns the same on each adjuster. If the carbs are synced at idle and at WOT, good enough for me.

 

I haven't used one of those gauges, I use the one that snowmobile-online has on their tech pages, using some tubing from a pet supply store (about $5 worth), and a piece of plywood with some lines drawn on it.

I sync'd them using the gauge I built, then checked them mechanically. They were dead nuts on with the gauge I built. I also tried synching other's sleds mechanically, and then using the gauge, and they were perfect, too.

Mechanically, I set them all the same at idle, using a drill bit that I can just fit under a slide, adjust them all the same. Then use a larger drill bit and put under 1 slide, and then clip the throttle cable so that I can just fit the drill bit under that slide. Adjust others so that they are all the same. Then double check full throttle operation. Re-adjust if necessary.

I have done my sled this way for years, and also quite a few friends of mine.

 

I do take a drill bit to get a start point and finish the job by vaccum. I was never able to have my adjustment spot on with drill bit. There is always some difference with the drill bit that your eyes wont see but the vac will.

 

i just use my fingers and make sure both slides come up at once.

 

i would have to agree with Paul on this one.,

 

A 'syncing' tool can be built very cheaply, all you need is some tubing, a board and some anti-freeze

Easier starting, crisper throttle response, all around better performance...you can sign me up!

 

On the new TM's with connector between the slides, you just have to verify that they're both the same at idle (drill bit works). Then just do Paul's method and if you're a perfectionist like me, you'll get them synced better than a gauge (I've never seen a difference when compared).

Gauges are a waste of cash and/or time.

G MAN