'67 Evinrude 40 STILL w/ no power

[swierczt]

Hello,<br /><br />I have a '67 Evinrude Big Twin (Mod# 40703E SER# E01637) with little power at full throttle. I got some suggestions with my last post (see '67 evinrude 40HP w/ no power posted last week) I checked the spark on both cylinders, both are bight blue. On the water, I unplugged and grounded each cylinder one at a time an started the engine...and it ran, poorly, but it did run on one cylinder. I reset the high speed needle also about 3/8 of a turn out...anymore and the engine floods and stops running. I checked the compression and both cylinders read 97/98 lbs. I am at full spark advance, the plate rotates all the way to the stop, but I still can't seem to get more than 1800 rpms out of it. It seems to burn lots of fuel...too much I think actually...so that's where I'm at. any help is appreciated!

 

[The Marine Doctor]

Re: '67 Evinrude 40 STILL w/ no power

Unlike most other engines...the low speed needle does affect high speed with this particualar carb. Along with the high speed jet<---of course.<br /><br />Check the setting of the low speed jet as well.<br /><br />What I would do though is pull the carb off...rebuild it and then retry a lake run.<br /><br />TMD

 

[swierczt]

Re: '67 Evinrude 40 STILL w/ no power

Thanks, I'll try reseting the low speed too...could it be open too much? It starts very easly and idles well...as slow as I want to go. I just rebuilt the carb...everything is new inside, except for the needles, but they look fine. What about the reeds? Most people have told me not to bother with those though.<br /><br />Thanks!