#2 Piston Isn't Even Moving...

Hi guys... I've been reading this site for quite a while now... But I just now got a reason to post... So here we go...

I have a 1960 Evinrude 5.5HP... The guy I got the motor from, told me that it only runs on one cylinder... I checked the compression, and NOTHING on the #2 cylinder... I then noticed, that the piston isn't even moving up and down when the motor is being turned over...

Wanna hear something even wierder than that? Well... The motor runs... SMOOTH too... No rattle, nothing... Like the rod may have actually been taken off the crank...

Any ideas on where to start? lol :/

Re: #2 Piston Isn't Even Moving...

These small engines use bushings instead of roller bearing's on the crank, and rods. I would guess the rod has to be broke, or the rod cap came off, if the piston is'nt moving at all.

Re: #2 Piston Isn't Even Moving...

An ex boss of mine once bought a tractor with a two cylinder pup start.
No compression on one.
Pull head, piston and rod missing.

Re: #2 Piston Isn't Even Moving...

Hi WC,
Sounds like the motor has to come apart. The rod has let go - I'm guessing the top one as that is the one that usually goes. Often happens for one of two reasons – Either the motor was really stressed (like trying to power a big tin boat full of guys and gear) or was run on 50:1 oil mix.
I once drove a 1955 Evinrude 7.5hp for about an hour after a rod let go. The motor NEVER let us down and even with daylight showing through the top crankcase, it kept on going on the bottom cylinder and got us home.
If you're lucky, the rod didn't hole the crankcase or the block, in which case a new rod and crankshaft may fix it up again. It's rare that the bad rod doesn't scorch the crankshaft in the process. These motors are fairly easy to take apart and rebuild as there are no little needle bearings to lose or account for. In my opinion, they are worth the effort, as they are in the top five best motors OMC ever made. Crankshafts, rods and even powerheads turn up on eBay fairly regularly. Also worth a look through your local marina graveyards as you never know what you'll find... Good luck!
- Scott

Re: #2 Piston Isn't Even Moving...

Thanks guys for all the insight... I'll probably tear it down once I get my 3HP back up and running...

Guess in a way, I'm somewhat lucky... The piston was fully extended when whatever happened, happened... Like I said, it runs so smooth, and if I hadn't been tuning it up at the time, I wouldn't have ever known what was going on with it...

Does any one know a good place that caters to these older engines? I'd like to use a reputable place, and try to use Ebay as a last resort...

Again, thanks guys for all the insight!