Please help with main jet part #'s

[Jeb1971]

Hi.
I have a '79 Evinrude 140. I have added the boyesen reed valves and aquired the low spped jets in 2 sizes bigger.
I was told by a boat mechanic that It might not hurt to go 1 or 2 sizes bigger on the main jets because of the gas we have today, plus for better performance with the new reed.
Problem is that my local Evinrude parts shop cannot find part #'s for larger main jets for that motor.
All he can find is for the stock ones. If I can get him the part #, he can order me the jets.
Right now, my carbs have main jets marked: "65C"
Does anyone have a chart with part numbers and sizes for this type II carburetor?
Thanks, John

 

[Dhadley]

Re: Please help with main jet part #'s

All the jets are listed, by size and part number, in the front of an OE service manual. Guess your E-rude shop hasn't ever looked at one.

What grade fuel are you using?

 

[Jeb1971]

Re: Please help with main jet part #'s

Hi. Thanks for your reply.
I use premium 92 octane fuel from chevron or 76 and omc 2 cycle oil.

Thanks, John

 

[Jeb1971]

Re: Please help with main jet part #'s

I will go to his shop tomorrow and ask to look at his manual (if they have one) and locate the part # for the bigger main jets. Do you think the boyesen reed valves warrant a size up in main jets?
Thanks, John

 

[seahorse5]

Re: Please help with main jet part #'s

I will go to his shop tomorrow and ask to look at his manual (if they have one) and locate the part # for the bigger main jets. Do you think the boyesen reed valves warrant a size up in main jets?
Thanks, John

Be sure to look in a 1997 or earlier manual as '98 and later motors are EPA certified and cannot be legally modified.

 

[Dhadley]

Re: Please help with main jet part #'s

If your motor is modified so you must use 92 octane, yes, I'd go a couple sizes larger on the main. If it's stock (as produced, including spark plugs) with the exception of the reeds you don't need more than 87 and you won't need bigger jets.

 

[Monkaroo]

Re: Please help with main jet part #'s

Try this link . Tashasdaddy sent it to me . It has been a real help on diagrams and part numbers .


http://www.evinrude.com/en-US/Accessories/Literature/Engine.Diagrams.htm

 

[Dhadley]

Re: Please help with main jet part #'s

Remember, stick with "C" jets, not "D" jets. Both, along with idle jets, will be listed. Don't get them confused.

 

[Jeb1971]

Re: Please help with main jet part #'s

Thank you Dhadley for your advice.
My motor is stock with the exception of the Boyesen reed valves, So I will stay with the stock main jets and run the 87 octane fuel.

John

 

[Jeb1971]

Re: Please help with main jet part #'s

Thank you all for your advice,
John

 

[Dhadley]

Re: Please help with main jet part #'s

No problem, that should be a very good running crossflow.