1968 Evenrude Fastwin 18 horse hick-ups

[redneck egbert]

I recently acquired this motor so I don't have a lot of history on it. I did take it fishing and for a test drive on Saturday. When running this motor, all sounded good until I opened it up and ran a little faster. The motor put my little 14 footer aluminum on a plane very quick, then it began to hick-up. This is the best I can describe it. The motor had a thump, then it would pick right up and keep going. If I stayed at high speed the thump became more frequent, as I slowed so did the thump. There was a speed that i could run that it never happened at all. Any help or suggestions would be great. Thanks

 

[bgbass.1]

Re: 1968 Evenrude Fastwin 18 horse hick-ups

possible dirty carb. should rebuild high speed jet dirty

 

[samo_ott]

Re: 1968 Evenrude Fastwin 18 horse hick-ups

I have the '66 Fastwin that I run daily in the summer... Bgbass is correct, it's probably a dirty carb... especially if you know nothing about the history of the engine... pull it and drop a kit in, they're cheap and easy to do... the high speed jet is a tad harder to get out this model as it's fixed... check the forum on making the tool for it... Also, if you do not know the engine, change the impeller asap... and finally check the coils, if they're original, change em... it's possible that it is an intermittant short that is causing the hiccup, but it's more likely the carb...

 

[redneck egbert]

Re: 1968 Evenrude Fastwin 18 horse hick-ups

Thanks for the help guys. I am going to find and install a carb kit. I also have plans for an impeller before it goes out again. I am fairly new to boat motors, but this is more than a stall, it is a hard thud. There is no stall in the motor. Its almost as if you were to take a hammer and whack the motor with it. It vibrates the whole boat and keeps going. Not doubting anyone with more knowledge or information than me, just want to make sure and describe it clearly. Thanks again guys.

 

[samo_ott]

Re: 1968 Evenrude Fastwin 18 horse hick-ups

Oh, that doesn't sound good. It sounds like the clutch dog is slipping and the engine is popping in and out of gear. This is a bad scererio and will trash your LU gears if you keep it up. Ensure the shifter is adjusted properly and if so then you'll need to open up the LU and see what the issue is. You might need a new clutch dog or worse, you might need gears.

 

[tashasdaddy]

Re: 1968 Evenrude Fastwin 18 horse hick-ups

agree with samo