Low compression in one cylinder

[csdsriggs]

I did a search through the archives but I'd like to get some opinions. I have a 1991 115 Evinrude, it has been running bad for a while,hard to start, loss of top end speed and stalling on takeoff. anyway we ran a compression test on it this weekend two cylinders tested at 100 one of them was 110, but the last cylinder tested at 60. I am going to decarb the motor, but do you think it is salvageable? what are the chances that the compression will come back up? <br /><br /> Thanks in advance<br /> Chris

 

[Dhadley]

Re: Low compression in one cylinder

Welcome!!<br /><br />If the low cylinder is on the starboard side, it may need more than a decarb. Try it and see if there is an improvement. We'll go from there.<br /><br />Good luck!

 

[csdsriggs]

Re: Low compression in one cylinder

I'm afraid it is. The top cylinder on the starboard side.

 

[Dhadley]

Re: Low compression in one cylinder

If you haven't changed the deflectors in a while I'd just pull that head to take a peek. If it broke the rings we really dont want to run it anyway. If nothings broke then we can repalce the little rubber deflectors and install a new head gasket.

 

[Hotrods]

Re: Low compression in one cylinder

I have the same problem on my 93.<br />Pull the head you will be glad you did.<br />I have a... broken ring,damaged piston/head and was getting 75psi. and she ran great...<br />Am pulling power head for full rebuild

 

[procraftmark]

Re: Low compression in one cylinder

hotrod are you going to do the rebuild yourself? i have a 1984 rude 90hp with the "exact" same problem<br />but since i am no mechanic it was gonna cost me at least $2000.00 for a full rebuild! that is way out of my price range , so there my boat sits. How much do you figure it will cost ya?<br /><br /><br />mark

 

[Hotrods]

Re: Low compression in one cylinder

http://www.boatpartstore.com/powerhead.asp <br /><br />Im sending it here.. Im not wasting the 8 hours to get the PH off to do a /@zz job. you should check this out.. Norm prise for rebuild is arounf 2600...Get a repair manual, follow the directions to remove the Power Head. It's really not that bad..

 

[csdsriggs]

Re: Low compression in one cylinder

Well I finally got down to where I keep my boat. I did a decarb but like I figured the compression went down from 60psi to 30 psi. I pulled the head off and found 1 mangled piston. Obviously it had spit out a ring a while ago because the top edge of the piston was curled over.The heads and the cylinder walls don't appear damaged. I have been thinking about getting a new four-stroke motor. I have found a good deal on a suzuki and a honda.What is everyones opinions on the four-strokes? and opinions between the two? The suzuki is a 115 like my evinrude, but a fourstroke, my question is whether I can use my SS prop on the suzuki? since they are both 115's. And should the dealer give me something for the evinrude since it does have some good parts.

 

[Hotrods]

Re: Low compression in one cylinder

I am in the procees of rebuilding mine. I damaged the block a tad pulling it out and without that.. all new pistons rings fresh bore. 800$ It's really not that hard.