Evinrude 90 questions

**jorgeinmiami** · 01-02-2022, 12:38 PM

I purchased a Checkmate that came with a Evinrude 90 that the prior owner says runs and that he rebuilt it with all kinds of high performance parts.
I'm not interested in the engine as a new one is on the way.

Is this something of interest or just junk?

Here is what he told me he did to the engine.

That engine has been bored out 30 over . And re sleeved. It has forged Wiseco racing Pistons. The block has been ported 4 high flow. The heads are milled for high-compression. Polished and balanced racing crank. Exhaust tube has been shortened and opened up. The lower unit has been drilled out to let the exhaust out before it goes through the prop. For higher acceleration at lower speeds. Bigger carburetors with bigger Jets. Advanced timing. The engine runs just fine on 90 tes pump gas. It does have more power if you use 115 leaded racing gas. But it's not necessary

**perfmarine1** · 01-04-2022, 01:07 PM

A couple things wrong with his statement. although you can re-sleeve a crossflow, why would you to just bore .030 over? You can not mill stock heads enough to get hi compression. You need different year heads. Would love to know where he got a polished, balanced, racing crank, lol Advanced timing

that would be the wrong way to go. And if motor ran fine on 90 pump gas, 115 race fuel will not help, in fact it may hurt performance,
Why anyone would do all that to a 90 when you could sell it and get a 140 crossflow, same block size, for next to nothing now days is beyond me.

**FMP** · 01-04-2022, 02:28 PM

It must be true, 1st post in how many years....

**FMP** · 01-04-2022, 08:35 PM

Originally Posted by perfmarine1

A couple things wrong with his statement. although you can re-sleeve a crossflow, why would you to just bore .030 over? You can not mill stock heads enough to get hi compression. You need different year heads. Would love to know where he got a polished, balanced, racing crank, lol Advanced timing

that would be the wrong way to go. And if motor ran fine on 90 pump gas, 115 race fuel will not help, in fact it may hurt performance,
Why anyone would do all that to a 90 when you could sell it and get a 140 crossflow, same block size, for next to nothing now days is beyond me.

How many years did they build the 90hp v4 looper

**racervboat** · 01-05-2022, 11:40 AM

Must be one of those ficht hi-perf racing motas.

**perfmarine1** · 01-05-2022, 01:38 PM

Originally Posted by FMP

How many years did they build the 90hp v4 looper

True that could be a looper, he did not say, even though would still go 140 hp.

**racervboat** · 01-05-2022, 01:51 PM

Like this mod 140 13 inch i just built.

**FMP** · 01-05-2022, 01:53 PM

It has my curiosity if cut, hogged out, which pistons and sleeves, might be worth keeping?

**FMP** · 01-05-2022, 02:03 PM

Originally Posted by racervboat

Like this mod 140 13 inch i just built.

Remember seeing drawings the R&D did with a twin tuner setup, each 180° pair side had its own tuner in the leg, the chest still common to also have port to port signal.