99 225 mercury, can turn flywheel one turn then it stops HELP!

jsmith55 · #1 April 29th, 2003, 06:21 AM

First I thought it was a ground problem but then I tried to turn the flywheel with my hand. It will give one rotation either way and stop. I've droped the lower unit to see if the impeller was hung up, it seems okay. The lower unit seems okay. Nothing seems to be catching under the flywheel. I've taken all of the spark plugs out and checked to see if the pistons were moving, all of them move. The alternator is not stuck. What the heck else could keep it from turning? Please help.

dkondelik · #2 April 29th, 2003, 06:47 AM

mornin' js,

If the fly will go at least 1 full turn, i'd drop the lower and look there.

If she moves less the 1 full turn, might be bent rod. <EDIT> or a chunk of something (broke piston?) in a cylinder.Concentrate on the Power-Head. Can you pull the heads on this motor?

Good Luck

jsmith55 · #3 April 29th, 2003, 07:04 AM

I was hoping I wouldn't have to pull the heads. I would like for that to be the last resort but now I'm running out of options. Thanks

jim dozier · #4 April 29th, 2003, 07:07 AM

What happened the last time it was running? What have you done to it (if anything) since then. Did you just try and start it and it wouldn't start? Have you checked the starter bendix, it might be hung up. Is anything catching under the flywheel like a loose magnet or ignition part? Have you left any tools anywhere? Are there any screws missing near the intake system? Does it seem to move normally until it abruptly stops?

Whatever you do don't force it until you know where the problem lies. This could be something simple or it could be terminal.

It sounds from you initial description like something is catching something. The question is what and where.

1. Check for external obstructions and obvious things.

2. Check the starter drive.

3. Pull the lower unit. You have apparently done that.

4. Pull the flywheel and check underneath.

5. Pull the heads and check the cylinders.

6. Pull the carburetor and check the reeds.

7. Pull the heads and check the cylinders.

8. Pull the reeds and check the crank.

9. Pull your checkbook and check your account.

Good luck I'm hoping its something simple.

jsmith55 · #5 April 29th, 2003, 08:14 AM

I have not checked the intake, I will check that next and look for missing screws, bolts, nuts etc. I have not pulled the flywheel yet, but it doesn't look like there is anything caught. Yes it does come to an abrupt stop, I don't hear any rattling or rubbing noises. I hope I don't have to pull the checkbook!!! Thanks

jsmith55 · #6 April 29th, 2003, 08:24 AM

Oh, I forgot, last time I ran the boat, it ran fine, no problems or noises. Yes, one day it was running fine, the next day it would only make the single turn of the flywheel. (The starboard engine cranks fine.)