OK - here's a weird one?

So we were out on the lake today (first time on the "big" lake, have been staying on a smaller local lake up until now). We are cruising along at 20mph, 3800 rpm. All of a sudden, out of nowhere, a big impact. I was sure we had hit a tree stump or something. The engine continued to run, but rough. We made it to shore to survey the damage - and found nothing. No nicks, no scratches, no sign whatsoever of an impact. The prop was brand new so I would have know had it been nicked.

I tried to restart the engine and it would start and run in fast idle. But when I moved it to neutral and tried to put it in gear, it stalled. I tried this several times with the same result. I was able to finally get it in gear by revving it in neutral and then slamming it into gear. Once in gear, we were able to motor along back to the dock (about two miles). The engine was running a bit rough but it seemed to be powering us along OK. When we got to to dock, I killed the engine and then tried to fire it again. It fired, idled, went into gear, and ran with no problems!!!! It is running maybe a bit rough but other than that, you wouldn't know that a half hour earlier it wouldn't even idle or go into gear. It has full power and goes onto plane just fine.

I have to admit, I a bit stumped. I went from thinking that I hit something to thinking that perhaps I threw a ring to not having a clue what happened.

Any ideas? The wife and kids won't go back out until I figure this one out (can't blame them) so it might as well be dead in the water

Help!!!!!

1993 Four Winns 180 Freedom with 1993 Evinrude 115TLET

Re: OK - here's a weird one?

start with the basics, compression check all 4, spark check. check lower unit oil.

Re: OK - here's a weird one?

My motor did something like that last season. I think I posted a thread on it. I thought the gear box was going and I bought a parts motor just in case. Turns out the motor wasn't synchronized properly. Once adjusted properly it ran fine with no more banging.
http://forums.iboats.com/showthread.php?t=264250

Re: OK - here's a weird one?

I forgot to add yesterday that after I stopped the motor the first time to check it out and then had all the trouble restarting it, the trim/tilt motor was running constantly for a minute or so. At least I assume it was that motor since there isn't anything else in there that makes an electric motor sound.

I am still leaning towards me hitting something. Perhaps I was lucky and didn't tear up the prop. Would the tilt/trim run weird for a few minutes if it had taken a hit? And would taking a hit make the engine run weird for a while?

I'm going to get a compression tester and check compression first as TD suggested and then go from there.

Still scratching my head on this one.

Re: OK - here's a weird one?

Very well could have bumped something underwater, and the jolt dislodged something in a fuel line or carb and is causing the rough problem. Not sure about that, but it is a possibility. If you hit something hard enough, it could have unknown consequences that will show up down the road. Worst case here is damaged crankshaft. If you hit something and it didn't hurt the prop or lower unit, that force has to go somewhere, and could in the worst case scenario travel up the drive shaft and cause damage in the crankcase. I believe there was a thread on something similar to that happeneing last week.
Don't freak out just yet though, do as TD suggested and start with the basics. Sounds more like something got dislodged and then found it's way into a carb or something and blocked the flow, causing the no-start issue for a while until you "revved it up and threw it in gear," which could have broken whatever it was up some. Just a thought.

Re: OK - here's a weird one?

I talked to a guy at work and he suggested that I probably hit something on with the bullet or leg. That's what saved the prop. He said the motors are designed to kick up when they take a hit and the hydraulics had to re-equalize afterwards which is why I heard the pump running. He also said that when an engine takes hit like that, it causes the fuel in the bowls to go everywhere and jacks the floats up, etc. The engine will run OK as Hybrid said after everything settles back down (or I burn through the piece of gunk that got dislodged). He said I likely fouled the plugs and that is why I am running a little rough now.

That sounds reasonable to me. I am still going to do the basic checks to make sure nothing else got damaged but I am definitely freaking out a little less now.

Thanks everyone for your input!!