vintage evinrude boat engine trouble

[jmagic]

I recently bought a 1964 Evinrude boat with the 88 hp sterndrive. I've been through the ignition system, replace both sets of points, condenser, cap & rotor. coil. The wires which are solid core all checked with ohm meter. Firing order checked and corresponds to numbers on cap and cylinder heads. Everything correct in the respect to the proper parts for a 12 volt battery ignition. Checked timing, flywheel mark lines with TDC and distributor mark. The fuel lines and fuel pump replaced, no garbage in the system and working properly. The four barrel carb. removed,every jet and port blown clean, new needle and seats, floats checked for adj., reeds checked and new gaskets installed. Compression test, 100 psi all cylinders. The engine has an oil injection system. Thermostat and water pump replaced.
With that all done, engine starts and take for test ride. Sounds O.K run it to speed. Goes to full throttle for a bit but then begins to loose power and the boat drops off plane. Rechecked all systems, everything checks out. Boat looses more power to the point where it can no longer handle the load while in gear. Hard starting without the choke, can throttle up in neutral, but once in gear stalls. Check the plugs, look very oily, also a good slick in the water. The engine is equipped with the vintage oil injection system which runs off the back of the distributor
It is my guess that either the carb. is shot or the oil injection system is not regulating the oil properly. Anyone had any experience with this type of unit. Any help would be appreciated

 

[R.Johnson]

Re: vintage evinrude boat engine trouble

It's been a long time since I've seen one of those. Are you running on the built in fuel tank. Hook it up to a remote tank on pre-mix, and see what you get.

 

[freddyray21]

Re: vintage evinrude boat engine trouble

agree. I would disconnect the injection system and run it on premix and see.

 

[freddyray21]

Re: vintage evinrude boat engine trouble

I would also check the vent on the tank. Might be air lock.

 

[tx1961whaler]

Re: vintage evinrude boat engine trouble

..and could you post some pictures? I've never seen one of those....

 

[F_R]

Re: vintage evinrude boat engine trouble

It is the 100hp outboard modified to run horizontally.

EDIT: Or rather it's the 90hp, modified

 

[tx1961whaler]

Re: vintage evinrude boat engine trouble

Found some pics here:
http://www.ultimate.com/omc-boats/gallery/sweet.html
...about halfway down the page

 

[R.Johnson]

Re: vintage evinrude boat engine trouble

What condition is the out drive in, both gearcase, and intermediate housing?

 

[jmagic]

Re: vintage evinrude boat engine trouble

Thanks for replies, definite avenues that I have not investigated. Will disconnect oil injection system and run on pre mix aux. tank. The engine is the modified 90 hp designed to run on its side. Also the sterndrive has been dis assembled and check, everything looked good. As for pics, a story of the boat and pic have been directed to the Evinrude OMC boat website, but aren't posted as of yet. I will put a posting up as soon as I try all suggestions to report all results

 

[jmagic]

Re: vintage evinrude boat engine trouble

O.K. I've disabled the oil injecting system, checked the gas tank for proper vent, fuel delivery and cleanliness. Fuel pump checks out (new). Double checked ignition system, installed a temporary gas tank with oil mix. Oh compression check 100 all four cylinders.

Took the boat for a ride, started a little hard but started. Put in gear got about 100 foot of dock, engine starts to loose power and stalls. Won't restart without choke, then only go for a minute and stall.

Finally got back to the dock. Engine running at high idle I adjusted the low speed needle valves to try and get the engine to run smooth. #3 cylinder missing and adjusting the jet makes no difference. Though the carb has been off and rebuilt, I'm think it's the problem. Any thoughts?