175 Oceanrunner compression/smoking/carb

[pak_ratt]

What are good compression numbers for for this engine?

I measured the following

Port side Starbord
105 106
104 108
104 104
The engine smokes at idle and after starting I see some fuel from time to time in the water. I have been told it should have compression of 150 140 lbs from what I read this engine was a low compression engine so I think what I am being told is not correct. The engine runs pretty good I a leaning towards decarbing with sea foam and maybe rebuilding the carbs because is see some fuel weeping by the bowl gasket on a couple of them. I also see some fuel in the engine cowling and might be leaking out of a carb when the engine is tilted back? One of the local marine mechanics is telling me the rings are shot because the compression is low?

Please somebody help me with this my daughter is getting married and her wedding is costing more than boat upkeep !!!!!

Thanks
Tim

 

[rcracerx]

Re: 175 Oceanrunner compression/smoking/carb

What year?

Those numbers are darn close to my 93 175 OceanPro. They look fine to me.

Rc

 

[pak_ratt]

Re: 175 Oceanrunner compression/smoking/carb

Thanks for the reply. Sorry the engine is a 1996. Does your engine smoke on startup or at low rpm?

 

[Fl_Richard]

Re: 175 Oceanrunner compression/smoking/carb

Those numbersw are prefect! That motor will run a long time. Sounds to me like the local mechanic needs some work.

Get that girl married and off on her way and GO BOATING!!!

Use synthetic oil, it will help with the smoking. The fuel sheen on the water is probably coming from the motor pan. Clean it out good, fuel will pour out the carbs when you tilt the motor all the way back. It's normal. GO BOATING!

 

[jonesg]

Re: 175 Oceanrunner compression/smoking/carb

I'll swap rpms if you're not happy with yours.!

What counts is they are even, as long as you get good rpm's its great.

tell mechanic to put new rings in his car if he wants some work.

Save the rings for the wedding.

 

[Chiliando]

Re: 175 Oceanrunner compression/smoking/carb

1. Congratulations on your daughter and have a great time at the wedding.
2. Time to get a new mechanic as your compression numbers are great!
3. Enjoy that boat!

 

[Bifflefan]

Re: 175 Oceanrunner compression/smoking/carb

I have been told it should have compression of 150 140 lbs from what I read this engine was a low compression engine

A low compression engine has nothing to do with the compression test.

A high or low compression engine is the "compression ratio"
That is the volume at bottom dead center vs. the volume at top dead center.

A "compression test" is the pressure that the piston can push. Which will tell you if there is a problem or not. there is another test to see what the problems are. its a "cylinder leak down" test.

105 is the very low end of what you want to have for a compression test.

 

[Fl_Richard]

Re: 175 Oceanrunner compression/smoking/carb

Bifflefan - 105 is GREAT for a 175 looper.

Down around 70 is the very low end of what you want to have for a compression test. That engine didnt have 150 coming off the assembly line.

 

[another todd]

Re: 175 Oceanrunner compression/smoking/carb

A low compression engine has nothing to do with the compression test.

A high or low compression engine is the "compression ratio"
That is the volume at bottom dead center vs. the volume at top dead center.

A "compression test" is the pressure that the piston can push. Which will tell you if there is a problem or not. there is another test to see what the problems are. its a "cylinder leak down" test.

105 is the very low end of what you want to have for a compression test.

Excellant point, I hadn't even thought of that till I read your post.

 

[pak_ratt]

Re: 175 Oceanrunner compression/smoking/carb

Thanks for the replys but does anyone really know what the compression numbers were on this engine new? Thanks Tim