compression question

[junior1113]

1993 200 hp evinrude ocean pro 90 90 87 94 94 90 good or dont buy boat thanx in advance

 

[JB]

Re: compression question

Good

 

[junior1113]

Re: compression question

is this a decent motor?? what is comp when new???

 

[crb478]

Re: compression question

Ideally you would like over a 100psi and fairly even. They are fairly even, and actually may be over 100psi. Unless you have had your compression gauge calculated it can easily be out 10-30 psi. Even if it is not reading accurately it likely is reading consistantly so I would not have any problem with that motor.

 

[rsimmons42]

Re: compression question

I agree, you are pretty consistent between all cylinders. which tells me that your gauge could be giving you a faulty reading.

 

[junior1113]

Re: compression question

my evinrude 140 comp was 130 on the same guages so this 200 must be in the 90,s ???????? thanks for any help

 

[jonesg]

Re: compression question

If you get the factory manual and look up the compression readings you'll not find any specific numbers, what the manual does say is they should be within 10% of each other. I'll swap your readings for mine and mine runs good.

 

[coolguy147]

Re: compression question

decarb

 

[crb478]

Re: compression question

decarb

Yep that would be the next step. You might easily gain 10 psi.

 

[5150abf]

Re: compression question

If those readings were taken on a cold engine you are okay if it was hot they are probably on the low side of acceptable, with the engine hot they should go up a good bit, mine is 110 cold and 135 hot.( '81 50)

You are looking for +- 10% so you are good there and yes a decarb could bring them up and probably needs done anyhow, can't hurt.

If the guy you are buying the boat from doesn't know alot about engines you could use those numbers a negotiation tool.

 

[JB]

Re: compression question

Those big V6s often read in the 90psi range when in excellent shape.

 

[junior1113]

Re: compression question

motor was cold and throttle was at idle when test was done dont know a whole lot about it