I have read thru every thread on the HAMB about 6x2 setups.I know what the problem is, don't know how to fix it. All carbs have been rebuilt, idle circuits blocked on the secondarys, new throttle shafts, 5 degrees plates in primarys,12 degree plates in the secondary. Setup to carbs by blocking off five hole with plates. Set each primary carb one at the time. Once these were setup I removed one middle plate bolted the second primary carb on and used a Uni-sync to balance the carbs. The pair idles great, starts great,Hell I even drove it down the road, it ran great.Then I bolted on the secondary bases, no tops, so that I could be sure all the throttle plates were closed and that the linkage was correct. When it starts it revs to about 2000 rpm and runs like crap. I know it is a vacuum leak, but all plates and shafts are new. Bases do not appear to be leaking at the manifold. The throttle plate fit is not as good as i would like, you can see some light around some of the plates, but they will hold water for about a minute before they leak. Where do I go from here. Any suggestions Thanks Robbie
I'm thinking that if you have a vacumm advanced dizzy, that could be the problem..when you open all the carbs your vacumm will drop and the dizzy can't respond..Try a machanical dizzy..Just a thought.. Duane.
I think with that much available venturi you need to find the vacuum leak.With 6 carbs I think you have a lot of areas that can leak.Just a little bit on a couple can add up.I would try to block off every one but the primary.IF it runs ok then unblock just one more at a time to see if it is the culprit.My 2 cents......
could also spray WD-40 at the base of each carb and throttle shaft while engine is running and it will momentaraly seal the leaking area, dropping the idle and telling you where the problem is.....works on my '34 Vicky 6x2's issue's when they screw up....mostly because we don't drive our rod's enough...my 2 cents