HELP ME PLEASE!!!! 1963 75hp, water choke, venturi, spark test...

[MrsFish]

Okay so the issue is a severely bogged down motor. I have had the thing running great one minute, then next time I start it it's a dog. Compression is 76 in 3 and 74 in the cylinder needing an insert. I have yet to check for "consistant" spark cause I had to helicoil one of the plugs (maybe this will solve the problem but I doubt it). Since I had the cylinder cover off the one side I figued may as well clean and re-gasket both sides. Pistons and cyls look good but alot of carbon. Anyway I suspect the following things are problems... First I have a water choke assembly?!?, choke never closes. Second it appears that somebody changed out a venturi once upon a time and the #'s do not match. I would like to know how the venturis are supposed to behave? One of them is a slow drip and the other is about 5x faster of a drip, almost a stream. I eat fuel like you would not believe but I have no frame of refrence since this is my first boat. 1964 16' Glastron Skiflite.

 

[Joe Reeves]

Re: HELP ME PLEASE!!!! 1963 75hp, water choke, venturi, spark test...

The compression psi will vary sometimes between gauges and the speed of which the enfine is cranking over. The fact that the psi numbers are extremely close to each other is a good sign.

The "water" choke should also be an electric choke that shuts when the choke is engaged. It should also be able to be closed manually.

The venturi as you call it, if that item is one of the brass nozzles that is screwed into the bottom portion of the carburetor, in back of those 7/16" hex head bolts, they are not venturis...... those items would be the high speed jets. They are part #328546, are imprinted with the number 72D, with the ID being .072 .