aq151 runs rough after twin carb rebuild Help

[chesapeakeclassic]

OK
I just completely rebuilt both Solex 1bbl carbs on my AQ151. Last year the boat ran okay and started first turn of the key, but had a rough spot in the rpm range around 1500-2000rpm where the boat would backfire and sometimes stall until i gave it more fuel. This was the only problem spot in the rpm range. Figuring this was a carb issue I decided to start this crabbing season with a fresh rebuild and tune up. The rebuild on the twin Solex included New gaskets jets fuel float stop "jet" the whole works. Now I started the boat, set the idle to 850 per manual, but now same problem. Engine wants to die when you give little increase in fuel but runs great when you punch it. Also if i only run off the front carb by placing a rag in the rear, it runs better. Runs bad reversing this scenario. Main venturi jet on front has good flow, rear only when heavy reving. I set timing to factory, dwell and points to factory, and new spark plugs but still same problem

Has anyone had this problem, or can anyone offer new suggestions? I have a very good mechanical background and have had other good mechanics scratch their heads but no solution.

Thanks

 

[sqbtr]

Re: aq151 runs rough after twin carb rebuild Help

Have you checked compression and valve lash? Did you sync the carbs after the rebuild?

 

[chesapeakeclassic]

Re: aq151 runs rough after twin carb rebuild Help

I have not done either. Compression check is next on my list just to make sure I am not dumping money for nothing. The carbs were both set to factory specs before install, but i don't have a UNISYNC tool.

I did do a tune up on the motor today, "the parts were on the way so i figured i would give it another shot". Replaced points, distributor cap, rotor, wireset, and plugs. Motor sounds smoother when its running but still has same issues.