I have a 1995 Evinrude 150 Intruder that I recently purchased that also had the leaking carb problem.
My carbs were leaking from around the float bowl gaskets and from the steel ball that was pressed into the float bowl (to close off a drilled passage).
The leaking apparently had been going on for a long time, because of the amount of oily residue that had collected inside the engine and on the garage floor. Fuel mix was literally dripping from the trim tab anode...
After much investigation in on-line forums, I decided to remove the carbs to check two things:
* are the float bowls warped?
I used a straight edge and quickly determined that each of the 6 float bowls was warped - some some more than others, but all were warped beyond the gasket's ability to seal them to the carb body. Rather than purchasing new bowls, I decided to try to sand the sealing surface to remove the warp. I used a sheet of 100 grit sandpaper, fastened to a flat surface and began to carefully 'polish' each float bowl. I stopped when I saw sanding marks across the entire sealing surface. I then rechecked each bowl with the straight edge and resanded, if I saw warpage. Some of the bowls took several passes to finish.
Next, I thoroughly cleaned each bowl using spray electronics cleaner (will not attack the plastic used in the bowls) and blew each out thoroughly with compressed air.
Next step:
* reseal the steel balls with ?
After cleaning each of the recesses where the steel balls are (again using electronics cleaner and compressed air), I mixed up a small amount of epoxy (I used JB Weld) and applied liberally to the orifices where the steel ball sits. I made sure to force the epoxy as deeply as possible into the cavity and also made sure that there was a slightly domed area left over the cavity when done. I left the float bowls sit overnight to fully cure.
After 24 hours, I reassembled all 6 carbs, and did not use new gaskets, since the old ones felt very pliable. I did use a torque wrench to make sure I did not over tighten the bowl to the carb body (I believe 25 in/lb) and the carb flange to the engine (45 in/lb). I did use the recommended "special" Phillips-like bit to tighten the screws. After assembling, I let the engine sit for another 24 hours, just to be sure the epoxy had fully cured.
Finally, I reattached the fuel line to the pump and filled the float bowls, using the bulb.
Viola - NO LEAKS.
I then let the motor sit again overnight and checked for leaks - NO LEAKS.
I trimmed the motor up to create a worst-case situation and NO LEAKS.
6 weeks later and several trips to the lake later, NO LEAKS.
Total cost of this repair was ZERO, since I already had the electronics cleaner and epoxy on hand. Actual labor time was about 4 hours over the course of 3 days. I work very methodically.
As to why the float bowls were warped, I think they were overtightened at some point. The leaking steel ball issue looks like an incorrect adhesive / sealant was used initially from the factory. I can't say if Ethanol or carb cleaner use contributed to this failure.
This method may not work for everyone, but it sure did for me and saved me a lot of $$$ and provided great satisfaction with a motor that runs fantastic with NO LEAKS.
Bannister
