need info on drilling out jets/install larger jets

[roonie]

after much research i still am unable to find any info on how to drill out jets on this 1977 70hp evinrude. Model 70EL77S.
I have heard that some earlier evinrudes had to have the jets drilled and resized but have yet to find any info on this particular yr. and model of motor. thanks

 

[boobie]

Re: need info on drilling out jets/install larger jets

The only 70 hp mtr that I know of that needed jet drilling was the '76 models. There was a service bulletin out on it that was 3 pages long. Never heard of anything for '77 tho'. I've done the '76 ones and it worked.

 

[Monte1961]

Re: need info on drilling out jets/install larger jets

after much research i still am unable to find any info on how to drill out jets on this 1977 70hp evinrude. Model 70EL77S.
I have heard that some earlier evinrudes had to have the jets drilled and resized but have yet to find any info on this particular yr. and model of motor. thanks

Holley Carburetor makes a hand drill kit that does just that. It's hand operated. You might want to check harbor freight. Just remember, you can take it off, but you can't put it back on. Good luck

 

[boobie]

Re: need info on drilling out jets/install larger jets

The way I've been fetched up is you don't drill out jets 'cause it will screw up the fuel/air supply. Proper way is to replace them. The drilling can leave burrs in them.

 

[Monte1961]

Re: need info on drilling out jets/install larger jets

boobie that is the reason why it's done by hand. The hand bits come in like .006 up to If I remember,! to like .050". There designed for this kind of thing. They start about the size of human hair and go up. Check into it!

 

[boobie]

Re: need info on drilling out jets/install larger jets

From my old OMC service school days 40 yrs ago and up they told us never to drill out jets for the reasons I mentioned above. But then again what do I know, just following OMC service school instructors and engineering advice. And yes, I've drilled out jets the way you do, but Never a fuel jet.