Compression

[BJ Laster]

Today I was supposed to sell my Ranger. It has a 1985 Evinrude outboard on it. The people who looked at it decided not to get it for two reasons. First compression was 90 on all 6 cylinders. What is normal for this engine? Secondly when they checked the electrical stuff on the motor..can't remember what those spark cables are called. It showed no spark on both sides and they said it would need two new power packs. The engine will start when I hook it up to a water hose and all just fine. If all six of those spark plug cables were out would the engine still start? I offered to start it for them but they didn't want to.

Thanks

BJ

 

[gone bye bye]

did you check the kill switch?



mini

 

[Staci Matheis]

BJ -



In my mind, the most important thing with the compression is that it be relatively even all the way around. I don't know what the original compression was supposed to be - I would think about 120 to 140; so 90 is low. But what do they expect from a 20 year old motor anyway!



They're just being cheap! Let 'em keep looking!



me!

 

[BJ Laster]

UH OH! When they checked the compression they unhooked the kill switch. That was probably why it showed no spark!

BJ

 

[gone bye bye]

I knew it....have them try again!



Mini

 

[Staci Matheis]

Sounds like THEY don't know what they're doing.....

 

[Rob LaMoy]

Ditto on what everyone said. As long as the compression is even, (within a lb or two of each other) across all cylinders, you're fine. Without a ring job you won't have the original compression. And mini hit the spark issue dead on. Let 'em move on. They don't know what they're doing and like "me" said, what do they expect from a 20 year old motor. If it starts and runs, has equal compression and the lower unit is in good order, that's about all you can ask for. Spring is coming, it will sell.

 

[Chris Hines]

BJ

I had that motor on a ranger and when I had it rebuild the compression was 100 in all cylinders. That motar is still holding good compression. It sounds to me like they might be testing you out. Is that motor an XP? If it is and they pulled all plugs out to check it they should have taken the fuse out to the elecrtal desplacement unit ( box under the the fly wheel on top of carbs). If not it will sometimes blown as soon as it senses lack oc spark. This is to prevent it from burning it. the fuse is loacated above the inline fuel filter. It lookes like a red tube about 1 inch long. It tkes a small fuse. I am not for sure the size though, sorry. I hope this helps.

 

[Staci Matheis]

It sounds to me like you've got one heck of a good boat there, BJ..... Post it on our "Swap & Sell" board! With a picture!







(And then "ttt" it every once and a while like Mac and Tox do!)