Compression Test on Evinrude Outboard

[RitcheyRch]

What is the process for doing a compression test on an Evinrude V6 outboard???

 

[ONE-A-DAY]

Should be warm but if not it's not a deal breaker, readings will be a little low. Pull all the plugs and test the compression, throttle should be open while cranking the motor, all should be within 10 percent of each other. Find the factory specs for the motor so you can compare to your readings.

 

[RitcheyRch]

Thanks for the information.

Should I have water going to the impeller to not damage it?

Should be warm but if not it's not a deal breaker, readings will be a little low. Pull all the plugs and test the compression, throttle should be open while cranking the motor, all should be within 10 percent of each other. Find the factory specs for the motor so you can compare to your readings.

 

[ONE-A-DAY]

No need, your not starting it, just cranking it over to get a reading on each cylinder. Remove all the plugs then put the tester gauge in each hole, crank the motor for 5 seconds, note the reading and then repeat the process for each cylinder

 

[RitcheyRch]

Thanks. I've done compression tests on 4-cycle engines before but never on a 2-cycle. So, wanted to make sure there were no special procedures and find out about damaging the impeller.

No need, your not starting it, just cranking it over to get a reading on each cylinder. Remove all the plugs then put the tester gauge in each hole, crank the motor for 5 seconds, note the reading and then repeat the process for each cylinder

 

[ONE-A-DAY]

Thanks. I've done compression tests on 4-cycle engines before but never on a 2-cycle. So, wanted to make sure there were no special procedures and find out about damaging the impeller.

Same process, there is enough residual water in the impeller housing and water passages to prevent any damage to the impeller, plus your just blipping it for a few seconds anyway

 

[RitcheyRch]

Exactly what I wanted to hear. Thank you. :tbi

Same process, there is enough residual water in the impeller housing and water passages to prevent any damage to the impeller, plus your just blipping it for a few seconds anyway

 

[STV_Keith]

When I run my compression checks, I try to be consistent. Walt said 5 seconds of cranking. Since only one cylinder will have compression (the one with the gauge in it), it should be easy to hear when it comes around to that cylinder while on the starter. I generally want to hear it hit that cylinder 6 times, or as many as it takes until that cylinder hits it's peak value. Then do the rest for the same amount of hits, for consistency.

 

[DLow]

You may have a problem with the starter bendix kicking out with only one plug in on the Evinrudes. I typically have to leave all six plugs in and spin it. I agree with 5-6 seconds. Evinrudes have a wide range of compressions depending on year and HP. Like 85-125, so you are really looking for consistence without knowing what year/hp you are working on.

 

[RitcheyRch]

Thaks and will keep that in mind.

When I run my compression checks, I try to be consistent. Walt said 5 seconds of cranking. Since only one cylinder will have compression (the one with the gauge in it), it should be easy to hear when it comes around to that cylinder while on the starter. I generally want to hear it hit that cylinder 6 times, or as many as it takes until that cylinder hits it's peak value. Then do the rest for the same amount of hits, for consistency.

Thanks. This is for a '88 XP200.

You may have a problem with the starter bendix kicking out with only one plug in on the Evinrudes. I typically have to leave all six plugs in and spin it. I agree with 5-6 seconds. Evinrudes have a wide range of compressions depending on year and HP. Like 85-125, so you are really looking for consistence without knowing what year/hp you are working on.

 

[ONE-A-DAY]

Thaks and will keep that in mind.



Thanks. This is for a '88 XP200.

It's going to be low, most older omc's were low compression, I thinking like 90 or so.

If you want to do a leak down test on it let me know I have one and can help.

 

[RitcheyRch]

I remember the numbers being low once before when I did the compression test on it. I cannot remember and didn't save the information. I don't plan on doing a leak down test on it at the moment but if I decide I will let you know.

It's going to be low, most older omc's were low compression, I thinking like 90 or so.

If you want to do a leak down test on it let me know I have one and can help.

 

[outboardrick]

It's going to be low, most older omc's were low compression, I thinking like 90 or so.

If you want to do a leak down test on it let me know I have one and can help.

I don't think the compression got as low as 90 until later, probably 1990 and above. If I remember correctly my 88 V8 was 120 when stock. Also make sure your battery is completely charged and have a charger on it while testing, the OMC starters tended to turn slow and a low battery will effect the readings.

 

[RitcheyRch]

Thanks and thankfully the battery is fully charged.

I don't think the compression got as low as 90 until later, probably 1990 and above. If I remember correctly my 88 V8 was 120 when stock. Also make sure your battery is completely charged and have a charger on it while testing, the OMC starters tended to turn slow and a low battery will effect the readings.

 

[DLow]

So? Done yet? How is everything looking?

 

[RitcheyRch]

Will be doing it this morning

So? Done yet? How is everything looking?

 

[J.P.]

At some point OMC put small relief holes right above the exhaust port so if yours has those the compression probably is 90 to 100.

 

[sprintcvx]

Will be doing it this morning

It will be interesting to see the results. I have the same engine, that's never been apart, and want to test it this year as well.

 

[RitcheyRch]

I will let you know

At some point OMC put small relief holes right above the exhaust port so if yours has those the compression probably is 90 to 100.

It will be interesting to see the results. I have the same engine, that's never been apart, and want to test it this year as well.

 

[RitcheyRch]

Ran the compression last weekend. Port side was from 106-110 and starboard side was from 94-96. Spoke with my mechanic, Al Stoker and also Al's Outboard in Lake Havasu. All said that those numbers are good and nothing to worry about. I was worried that with one side being lower than the other there might be an issue. They all advised to not compare port to starboard. They said they are more concerned with being within 5psi per bank.

They also said those numbers might come up if I ran the boat longer than I did but still nothing to worry about.

 

[sprintcvx]

Ran the compression last weekend. Port side was from 106-110 and starboard side was from 94-96. Spoke with my mechanic, Al Stoker and also Al's Outboard in Lake Havasu. All said that those numbers are good and nothing to worry about. I was worried that with one side being lower than the other there might be an issue. They all advised to not compare port to starboard. They said they are more concerned with being within 5psi per bank.

They also said those numbers might come up if I ran the boat longer than I did but still nothing to worry about.

Thanks Richey:thumbup: Now I have number to look for. Good luck with the sale of your boat.. It looks badass:thumbup:

 

[RitcheyRch]

No worries and thanks.

Thanks Richey:thumbup: Now I have number to look for. Good luck with the sale of your boat.. It looks badass:thumbup: