How to tell if power head was changed

[Thatoneguy904]

I recently purchased a 1988 Evinrude outboard the model number says it’s 100 hp the guy told me he did change the powerhead from a 140. I got a deal on the motor but I would love to know how I can tell if I have 100hp or 140 hp .

 

[racerone]

Is the serial # the same between powerhead and sticker in picture #2 ??----Does exhaust cover have a bubble or is it flat.-----Post picture of exhaust cover.

 

[Thatoneguy904]

Is the serial # the same between powerhead and sticker in picture #2 ??----Does exhaust cover have a bubble or is it flat.-----Post picture of exhaust cover.

 

[Thatoneguy904]

I can’t seem to locate the numbers on the powerhead

 

[racerone]

That would be a 140 powerhead as I clearly stated it appears to be a 1979 powerhead rated 140 HP at the powerhead.----Would be around 120 HP at the prop.----Post your compression test numbers.

 

[Thatoneguy904]

That would be a 140 powerhead as I clearly stated it appears to be a 1979 powerhead rated 140 HP at the powerhead.----Would be around 120 HP at the prop.----Post your compression test numbers.

Ok thank you. How can you tell for future reference? I was getting mixed information from Google.
so it is a 140 power head someone put onto a 100 bottom end?

 

[racerone]

I thought I made it clear 1979 or older powerhead , but I guess not.