351W on '82 Ski Supreme Help

[smiley11]

I have just bought an 82 ski supreme with a 351 windsor. We have got it running, just rebuilt the carb (holley 4160 marine), and now it is backfiring. It idles well, but won't run over about 10 mph. The 4 barrels won't open up all the way. Is this a vacume problem somewhere? Timing? Any ideas...Please help if you have any idea. I really appreciate it..

thanks

[surroundsound64]

RE: 351W on

will it rev up w/ the prop disengaged?

[smiley11]

It will rev up and begin to backfire and sputter when the prop is disengaged. Also the gear switch blocks it from reaching too many rpms while not in gear.

[Andrew]

i've had similar symptoms with a bad battery, but i doubt thats ur problem....

[Fast351]

Check time first. Backfire is almost always an ignition problem. It could be a REALLY bad lean condition, but you'd have to screw something up pretty badly in the carb for it to be that.

[pj]

ya, if the carb just got rebuilt, i'd take a look at the timing too. sounds like the likely culprit. DOUBLE AND TRIPLE CHECK your spark plug wires that they are going to the correct cylinders for your firing order. especially if you have a pro-tec system. (speaking from experience here and a much thinner wallet)

[wristy_j]

I'm no mechanic, but I had a very similar problem that I was able to fix with some help. There's a vaccuum actuated rubber gasket that opens the second two barrels that will allow you to rev up and get to the high end. It's a flat disk looking thing with a metal wire sticking out of the bottom, mounted to the side of the carb body. Take that disk-like cover off and look at the vaccuum diaphragm inside (I think we actually had to detach the whole assembly from the carb body first). There's the main diaphragm, and then a separate little hole for the pressure to get in/out. I had my carb rebuilt by an incompetent mechanic, and he put a screw right through the ring gasket around that little hole, and left it that way. We taped it up with some electrical tape, re-cut the hole for the airway, put it back together, and voila - we were hauling *** all over the lake! Hope that helps!
J

[wristy_j]

"Metal wire" was probably a bad choice of words. It's more of a thin, solid, metal rod.