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View Full Version : 2 Problems, Need Advice, 78' Hondo, 427`



Fool Throttle
07-15-2006, 06:20 AM
Ive got 2 probs and needed some help.
1. i have the 427 chevy, Vitor jr intake, 830 Holley race carb. MSD dist w/ vac advance (but its unhooked). boat turns 5100 rpm at full throttle.
the problem is every time i go full speed for more than a few seconds and back off to an idle, the boat runs extremely rough and shakes like its only running off 7 cylinders??? it wont even idle below 2k and if it dies, I have to hold the pedal to the floor for at least 5 sec until it starts. If i keep it about 2k and then take off, it runs great just like normal, but below 2k, its like a plug wire comes off or something. If i let the boat sit for 30 min, or if i run the boat for 30 min around 3k, it fixes itself?
Could this be a problem with the vac advance dist? As stated above it is unhooked but i wonder if air could be blowing into the vac advance nipple and changing things? All plug wires and plugs look good.
2nd Problem. also after doing a full throttle run, there is a lot of oil that has sprayed out of my breather. The PCV valve is good and hooked up correctly. The filiter in the breather is a K&N billet and is good too.
Thanks,
Jay

Duane HTP
07-15-2006, 06:30 AM
Sounds possibly like a carb flooding problem from heat. Do you have an insulating spacer between the manifold and the carburetor? Are the heat risers blocked in the manifold? The gas could be getting hot and boiling over in the carb. Also possibly weak valve springs letting the lifters pump up at high rpm. Check your valve spring pressures. Just a couple of ideas to eliminate.

Cas
07-15-2006, 06:46 AM
I'm assuming you just got the boat? do you know much history of it, engine wise?
I had a 69 Chevelle that had a similar problem and it turned out to be a bad lifter......had a pin hole in the bottom of it. If the engine has a lot of hours on it, you could be getting some blow by that is causing the oil mist. If the engine is fairly new, maybe the rings aren't seated yet?

Fool Throttle
07-15-2006, 08:50 AM
the engine was rebuilt not long ago. i has an aluminum 1" spacer and i do notice water on it once in a while.