1990 Evinrude 20 HP - Add Electric start / charging & maybe bump to 25 HP ???

ZigZaggin

Seaman
Joined
Apr 11, 2009
Messages
64
MODEL # E20CRESB

I'm going to look at a 20HP ourboard tonight and plan on checking compression and spark and doing a crackle test on the lower unit fluid. The motor supposedly has sat for the last four years in a guys basement so any tips on things to look for would be much appreciated. It's a pull start and I plan on converting it to electric start if I get it so here's my questions...

1) I'm interested in adding electric start and charging. What will I need to do this?
2) Is it just the carb that needs changed for the bump to 25HP or is porting different on the 25 HP as well? If it's only the carb i will probably do this.

3) Lastly, for this motor what would be considered "good" compression? I know you don't want much variance between the 2 cylinders but how low is "too low"

thanks in advance for your info - I will post results if I decide to get it and do the modifications.
 

jasper60103

Commander
Joined
Sep 18, 2008
Messages
2,055
Re: 1990 Evinrude 20 HP - Add Electric start / charging & maybe bump to 25 HP ???

MODEL # E20CRESB

I'm going to look at a 20HP ourboard tonight and plan on checking compression and spark and doing a crackle test on the lower unit fluid. The motor supposedly has sat for the last four years in a guys basement so any tips on things to look for would be much appreciated. It's a pull start and I plan on converting it to electric start if I get it so here's my questions...

1) I'm interested in adding electric start and charging. What will I need to do this?
2) Is it just the carb that needs changed for the bump to 25HP or is porting different on the 25 HP as well? If it's only the carb i will probably do this.

3) Lastly, for this motor what would be considered "good" compression? I know you don't want much variance between the 2 cylinders but how low is "too low"

thanks in advance for your info - I will post results if I decide to get it and do the modifications.

Zigzag,
it would be cheaper and less trouble to buy a 25.
Adding electric start is easy enough to do, but it will cost $100-150 if you
get lucky on ebay. More if you bought the kit from BRP.
I'm not sure about the carb thing. I've heard debates on this forum.
I would think 100+ on compression is good.
Good luck.
 

blimp

Petty Officer 1st Class
Joined
Sep 30, 2009
Messages
237
Re: 1990 Evinrude 20 HP - Add Electric start / charging & maybe bump to 25 HP ???

For adding electric start, you will need starter, bracket, solenoid, wiring, switch, and likely a new flywheel with teeth on it ($$).

You can actually get a post-'85 30HP carb and get a decent power boost out of those.

not sure about compression. Better than 100psi is good, but you may not even be able to get that with a rope start motor, even if the 'true' compression is great.
 

jasper60103

Commander
Joined
Sep 18, 2008
Messages
2,055
Re: 1990 Evinrude 20 HP - Add Electric start / charging & maybe bump to 25 HP ???

For adding electric start, you will need starter, bracket, solenoid, wiring, switch, and likely a new flywheel with teeth on it ($$).

You can actually get a post-'85 30HP carb and get a decent power boost out of those.

not sure about compression. Better than 100psi is good, but you may not even be able to get that with a rope start motor, even if the 'true' compression is great.

Good point, blimp. I forgot about the flywheel ($$).
 

ZigZaggin

Seaman
Joined
Apr 11, 2009
Messages
64
Re: 1990 Evinrude 20 HP - Add Electric start / charging & maybe bump to 25 HP ???

Hey thanks for the info! Good point on the pull rope and seeing accurate compression vs electric starter. 25's are evidently hard to come by. Every one i've found on craigslist seems to be gone by the time I call so I decided to look for a 20 and sure enough the guy still had it. It's real clean and the skeg looks pretty much like new. If I get it, I'll probably just leave it "as-is" unless I break an arm or something.
 
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dew2

Senior Chief Petty Officer
Joined
May 6, 2010
Messages
674
Re: 1990 Evinrude 20 HP - Add Electric start / charging & maybe bump to 25 HP ???

zigzaggin where you located,
 

ZigZaggin

Seaman
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Apr 11, 2009
Messages
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Re: 1990 Evinrude 20 HP - Add Electric start / charging & maybe bump to 25 HP ???

I'm in the quad cities (Davenport, IA)
 

78 mckee

Seaman
Joined
Feb 9, 2009
Messages
59
Re: 1990 Evinrude 20 HP - Add Electric start / charging & maybe bump to 25 HP ???

If you're patient, you can find complete electric start upgrades on Ebay. I purchased one before Christmas that included the flywheel, starter, bracket, rectifier, and everything else I needed for $150. But you need time to find them. There are lots of carbs that can work to increase output on these motors but you will also need to change the intake to use the larger carbs. The same powerhead was used on these motors from 20-35 HP. I have done this on my motors with excellent results.
 

ZigZaggin

Seaman
Joined
Apr 11, 2009
Messages
64
Re: 1990 Evinrude 20 HP - Add Electric start / charging & maybe bump to 25 HP ???

Final followup... Just wanted to say thanks to all the replies and great info. Long story short I went to look at that 20HP and it was literally like new. Not a mark on the prop or the skeg. Started first pull. I bought it for $700 used it for a season, and realized I wanted my Walleye boat back. Sold it in the spring of 2013 for a profit.
 
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