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1978 Evinrude 70 HP dies when given throttle in gear but not when in neutral.

S

shtimb

New member
I'm trying to resurrect an old 78 Evinrude 70 hp (model 70873C) for our first family boat. It starts up and idles great when in neutral, but when put in gear and given any throttle at all, it bogs down and dies. I can however throttle it up in neutral as well. Can anyone give me any ideas of where to start?

Thank you
 
Simple steps to do / report on first.-------Post the compression numbers.-----And see if you have spark that jumps a gap of 3/8" or more on a test device.----If those are good there are other simple steps to do.
 
Make sure the spark advance (timer base) isn't sticking. If it doesn't advance before the carbs open much at all, It'll conk out.
 
85 Top, 90 Middle, 90 bottom.

Referencing your comment, I realized that I never gapped the spark plugs out of the box. I did that with no precision (just took a flathead to them), took it back out and was able to get it up to plane, until I shut it off in the middle of the lake and couldn't get all cylindars to fire again and had to limp back.

Progress and thank you!
 
Compression is way , way too low.-----Perhaps test with another gauge.-----Or take cylinder head off to inspect for scored cylinders.
 
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