Sudden low compression

[2mate]

My 1998 25 evinrude be25elece has lost its compression by sitting for a week. It's now 100psi on both instead of 135. It was fine last week now won't even fire, have spark and fuel. Changed the head gasket today and still no better. Confused.....
Any ideas????

 

[nwcove]

Re: Sudden low compression

has to be more to it than just the compression loss as it should run quite well at 100 psi per hole. ( did you check the head for warpage when it was apart? )

 

[2mate]

Re: Sudden low compression

has to be more to it than just the compression loss as it should run quite well at 100 psi per hole. ( did you check the head for warpage when it was apart? )

head seemed fine, it wont fire at all and petrol seems to be coming out the prop.

 

[Mengwalton]

Re: Sudden low compression

head seemed fine, it wont fire at all and petrol seems to be coming out the prop.

PETROL SEEMS TO BE COMING OUT OF THE PROP ? :O I can only think of one way that can happen is there any obvious leakage from the lines into the cowl and then down into the leg? It seems strange that something has gone wrong whilst sitting a week I might be new to outboards but as a marine engineer I can tell you there shouldn't be petrol coming from your prop haha good luck i shall keep a eye on the thread be interesting to find out.

 

[Lyle29464]

Re: Sudden low compression

When you pump the bulb does it fill the carbs and get hard or can you keep pumping?

 

[Tim Frank]

Re: Sudden low compression

My 1998 25 evinrude be25elece has lost its compression by sitting for a week. It's now 100psi on both instead of 135. It was fine last week now won't even fire, have spark and fuel. Changed the head gasket today and still no better. Confused.....
Any ideas????

????
Posts like this always make me think we are getting less than 1/2 the story. :facepalm:
I may need to get out more often, but i have never met (or heard of) anyone who checked their compression weekly "just because".

If there is a ROOT CAUSE why you are checking your compression this often, sharing it with the forum will only help....honest...

 

[sutor623]

Re: Sudden low compression

????
Posts like this always make me think we are getting less than 1/2 the story. :facepalm:
I may need to get out more often, but i have never met (or heard of) anyone who checked their compression weekly "just because".

If there is a ROOT CAUSE why you are checking your compression this often, sharing it with the forum will only help....honest...

Maybe he just checked it cause it wouldnt start.

 

[oldman570]

Re: Sudden low compression

Have you hit anything with the motor while out the last time? Check the flywheel key.
Oldman570

 

[Tim Frank]

Re: Sudden low compression

My 1998 25 evinrude be25elece has lost its compression by sitting for a week. It's now 100psi on both instead of 135. It was fine last week now won't even fire, have spark and fuel. Changed the head gasket today and still no better. Confused.....
Any ideas????

Maybe he just checked it cause it wouldnt start.

But why was he checking it last week ....if he says it was fine???

 

[sutor623]

Re: Sudden low compression

But why was he checking it last week ....if he says it was fine???

Maybe he figures that his motor suddenly stopped working correctly because of the compression issue. I dont think that he meant that he checked it last week, just that last time he checked it, it was fine, and after he started having issues he checked it again. But who knows.