Help!!!

[The Outcast]

Hey guys, a good friend of mine went to start his 2000 115HP Merc today and he could only get it to turn over if he took the plugs out. He even put a rope on it and it would still only turn over if the plugs were out, any ideas before he gets a big shop bill and loses prime fishing time? Oil injected with carbs, new batteries... The motor will only turn over with the plugs out!

Say ya to da U.P., eh?

[Beave]

Can you back-drive the motor by spinning the prop? With the plugs out you should be able to get the motor to turn over pretty easily just by spinning the prop. (You'd have to be in-gear)

Two possibilities that I can think of assuming they are indeed new batteries that're fully charged...

1) The starter is going out. I'm not sure if it's a brushless starter or what, but if the starter isn't healthy it won't generate the torque required.

2) Corroded or loose wires somewhere. Your starter may not be getting enough juice if the connections aren't sound. Wires have a way of vibrating loose on boats.

I'd start by checking all the connections under the lid, then seeing if you can find a place that can test the starter. I'm not sure if an autozone is capable of testing boat starters.

[The Outcast]

Thanks for the reply, and I will have him try this, but even if he uses the rope it wont turn unless plugs are pulled???

[Beave]

That could be serious then. Sounds like there might be something wrong with the engine. Crankshaft bearings, push rods, a piston ring dragging maybe...? It sounds like there's something causing extra friction then.

THere are better here at diagnosing such problems than me, but if it's not happily turning over you could damage it worse by forcing it.

[The Outcast]

Thanks Beave for the info, I will pass it on. He said the motor will not turn at all with the plugs in, but turns with ease with them out. I am not a mechanic, but this is baffling.....

[Beave]

Turns with ease is what should happen. It shouldn't turn with the plugs in because you're compressing air in the cylinders.

I thought you meant it wasn't turning over easily even with the plugs out, and only then could you even get it to turn.

From what you described I'd go back to my first comments. Probably something with the starter or the battery.

[The Outcast]

Hey Beave, but shouldn't he be able to pull it with rope? Even if it just flips over once?

[Beave]

Again, I'm not an expert on boat motors. I'm handy around a car, motorcycle, or truck engine, but boats are a little different animal. I'd think a rope around the prop may not be enough to turn it over. Even without combustion you're compressing the air to over 100psi. That's a lot of pressure.

Wait for TONGA to come around. I defer to whatever he says.

[The Outcast]

Thanks again Beave, but what I meant was that on a lot of outboards they give you a pull rope for emergency manual starting. When he purchased the boat, he tried to start it like this, just in case he ever had to he wanted to see how hard it would be, and it started right up. Yesterday when it would not crank over with the electric starter, he put the rope on the flywheel and could not get it to turn over that way either.So what he did was pull the plugs and try it, and with both the electric starter and the manual pull and the engine turns freely. But put the plugs back in and the compression, I guess, is to much to overcome with the electric starter or the manual pull rope. The only thing different about the motor than when he put it away last fall is that he fogged the motor. This boat is garage kept and we are baffled. He pulled and cleaned the starter, it engages just fine and everything, but the motor just rocks once and stops, electric or manual start....ANYBODY?

[TONGA]

when he pulls the plugs,,what do they look like? any sing of contact?

[The Outcast]

I do not know, but I will ask him and get back to you.

[The Outcast]

Talked to my buddy and he said he finally got his outboard to crank. What he thinks was wrong was that theexhaust valves were stuck shut, possibly from fogging last fall.He ran a can of carb cleaner thru it and was finally able to free it up enough to start it. Unfortunately, he fried his starter in the process, and is looking at three bills for a new one. Thanks Beave and Tonga for your replies.


Say ya to da U.P., eh?

[TONGA]

is it a 4 stroke?,,,because if it's a 2 stroke the piston is the valve!

[The Outcast]

It is a 2-stroke, so I guess it wasn't a sticky valve. I don't know what it was but he said it is purring at idle speed anyway...?

Say ya to da U.P., eh?