Need help on big twin 40hp link and sync

[jake22si]

I have a manual but I cannot locate it at the moment, I have searched too long for it. Can anybody send some info on the link and sync for an 1969 evinrude Bigtwin 40hp? The outboard hasn't been run in almost 20 years, I got it running and took it out and it seemed like it would not reach top speed. I checked the points, cleaned the carb, and new plugs. thanks.

 

[lindy46]

Re: Need help on big twin 40hp link and sync

Probably running on one cylinder - check spark first.

 

[jake22si]

Re: Need help on big twin 40hp link and sync

Think I fixed the problem. Shift cable needed a little adjustment, wouldn't allow much more than half throttle if linkage wasn't fully engaged.

 

[jake22si]

Re: Need help on big twin 40hp link and sync

Has been off and on lately, not getting full power. It will go good for 20 seconds then bog down again almost like on 1 cylinder or not getting proper fuel. Carb kit rebuild and ignition tuneup on order. Checked compression first and is good at 115 psi each. Just the other day I was getting 22 mph on my boat with about 1000lbs total boat weight. Is that good for this motor? Hard to test at home because I have to trailer to the lake.

 

[jake22si]

Re: Need help on big twin 40hp link and sync

still can't locate my manual from all the books I have. could somebody send me the pages for the link and sync for this motor?

 

[jake22si]

Re: Need help on big twin 40hp link and sync

rebuilt the carb and found the problem. The 2 starter bracket bolts that go through the intake have stripped threads in the block. I carefully tapped for a larger bolt and sealed them up good. So it was sucking air the whole time. Musta been forcing too much air through the carb because I did spray starting fluid to see if I could find a leak but no luck. weird. But it runs great now. still questioning the 22mph though. And the shifting is kinda stiff.