My Frustrating Boat Purchase, 50 HP JOHNSON

First off, been reading your input on these forums for a while. Terrific responses and very intelligent posters. Now that I've buttered ya up (haha), I am in search for answers.

So, I bought a boat with a 1971 Johnson 50. Ran first day, but not to full potential and sputtered a bit. Didn't seem right. Same day, tried to start but it wouldn't go into gear without stalling.

Ran great on ear muffs. So took it to the shop, and they replaced carburetors. Now the boat at least shifts into gear and runs, but it won't plane out and doesn't go very fast. It's almost as if one cylinder is not quite right.

Did a compression test and it was A-okay. So, what the heck could it be?

Thanks very much for your input..

Also, a side question- if the compression is good, does that mean he shouldn't have to totally rip into the engine itself and that it's likely fuel related?

Have you checked the spark?

i have a 1972 25hp that did the same thing. im not an expert or anything but it sounds like your high speed jet is dirty or clogged. you say they replaced the carbs but were they NEW or rebuilt used carbs? try cleaning entire carbs including the high speed jets (inside the bowl).

sgtmaj83 said:

Have you checked the spark?

Click to expand...

The spark was good before it stopped running, it's been at the mechanic's garage ever since. Are we talking MAJOR bucks if the spark is bad?