1970 350 cheys problems

[chuck mac donald]

" I have a 28' alglass wit

" I have a 28' alglass with two rebuilt 350 cheys. and and having troube getting moe then 2200 rpm from the engines. this has been a project boat with motors out and no wiring at all in the boat. The motors had be rebuilt by the old owner.The motors run fine at low rpms but i can't get more then 2200 rpms. have checked the props,they are fine. Have adjusted timing it with in spec,s have checked volteage at coil and have jump 12 volts from battery to coil no change in rpms have tryed adjusing timing under a load no help and gone back and justed valevs no help, have i missed any thing? any and all help wouild be greatfull. "

 

[croozertoo]

"When both engines exhibit the

"When both engines exhibit the same problem, it's best to zero in on things the engines share, like fuel, air, common mechanical items and the boat itself. This assumes the props are the proper size and pitch for the engines to reach normal red line and that the engines don't have any other symptoms like smoking, missing or backfiring and can reach red line when not under load.

First, the boat itself. Are weight, balance and the bottom condition all normal? Next, mechanical stuff. Are the throttles opening the carb butterflies all the way? Are the chokes releasing after warmup? Is clean fuel reaching the carbs in enough quantity? Are filters and fuel lines clean and open? Are flame arrestors clean? Are exhaust manifolds, elbows and hoses all open and unrestricted? Are the transmissions and reduction gears okay?

Yes to all these would then point the fickle finger at the rebuilt engines. Is compression normal in all cylinders? Are the distributors advancing the spark curve properly? Are temps, sounds, and oil consumption normal? Do you know if these engines were "built down" with low compression ratios and very mild cams?

I may have missed something, but these should help with your detective work.

"