66 Evinrude 100hp Fuel

[jbrow0723]

Hi all,

I have a 66 Evinrude 100 hp (model 100639) that I am trying to get running. I checked the compression, it is around 65lbs straight across all four cylinders, and I have spark to all the plugs...so my next guess is a fuel issue. I am having a hard time locating a rebuild kit for the carb on line. Does anyone happen to know where I might be able to find one? I tried looking for it in the iboats parts area, but no luck. Any help you can give would be greatly appreciated.

also, the motor is backfiring through the water intake down by the propeller...is this something to be concerned with?

Thanks!

 

[jimmbo]

Re: 66 Evinrude 100hp Fuel

From what I understand, the gasket set for this carb is not to be found on this or any other planet. You might be able to make new ones using the proper material and a steady hand with an exacto knife. As for the backfire through the water intake. Do you mean the exhaust snout? the water inlet is in the front of it. Are the plug wires going to the correct cylinders? Your compression sounds a bit low but it could be the gauge as all cylinders are the same

 

[boobie]

Re: 66 Evinrude 100hp Fuel

How did you check your spark.? If you're just grounding out the plugs it tells you nothing. Spark should jump 1/4" on an open air gap tester. If the spark does this, then squirt some premix fuel in the carb throats and see if it will fire.

 

[tx1961whaler]

Re: 66 Evinrude 100hp Fuel

The carb gaskets are all available individually at places like marineengine.com. They are quite expensive, so it would be wise to take care if you plan on taking that carb apart.
Sometimes a backfire out the exhaust indicates a timing issue.

 

[F_R]

Re: 66 Evinrude 100hp Fuel

Don't be taking that carburetor apart unless you absolutely have to. As said, gaskets are dear and nearly impossible to make.

Belt timing correct?????
Plug wires on correct plugs????
Belt timing correct?????
Plug wires in correct distributor cap towers?????
Belt timing correct????
Breaker points gapped correctly????
Er......(belt timing?????)