Pull cord goes 6" and stops HARD - '94 Yamaha 15hp

[gettin'wet]

Hey guys, been lurking here for a long time, but first post. Tried searching and feel like I need more specific help...

On my '94 Yamaha 15hp (15MSHS) 2-stroke, pull-start - when I pull the cord it will pull out about 6 inches very freely and the I can see the flywheel turning. However, it then comes to an abrupt stop, as if the wheel is being stopped mechanically by some mechanism that I can't see. Also, when it does hit that stopping point it makes a metal on metal clanging sound.

The last time this motor ran was three weeks ago in a fresh water 55 gallon drum and it ran fine and pumped water. I don't know what could have happened since.

I can confirm that the engine IS in neutral, and I've even tried it systematically in every throttle position to see if that was the matter... no luck.

There is a pin that engages the teeth of the flywheel to stop it from starting which is connected to the gear selector (i.e. safety mech. to not start in reverse). I have observed that this is NOT the problem.

Does anyone have experience with this? Any advice is welcomed. I'm a novice at outboards, but comfortable with mechanics, just need to know what I'm dealing with!

Please help! ...and thanks for reading

 

[cousinabe]

Re: Pull cord goes 6" and stops HARD - '94 Yamaha 15hp

Take put the spark plug and see what happens.

 

[robert graham]

Re: Pull cord goes 6" and stops HARD - '94 Yamaha 15hp

Try it with the spark plug out, then if that doesn't change it, pull the recoil starter mechanism off motor to inspect for operation. Try turning flywheel with a wrench on that top flywheel nut just to see if it'll move. If a nut or piece of metal has come lose under the flywheel it will stick on the magnets and interfere and stop the rotation, so you may look under there, or even have to remove flywheel to inspect. There are a few nuts under flywheel that may vibrate off and cause this. Good luck!

 

[gettin'wet]

Re: Pull cord goes 6" and stops HARD - '94 Yamaha 15hp

Try it with the spark plug out, then if that doesn't change it, pull the recoil starter mechanism off motor to inspect for operation. Try turning flywheel with a wrench on that top flywheel nut just to see if it'll move. If a nut or piece of metal has come lose under the flywheel it will stick on the magnets and interfere and stop the rotation, so you may look under there, or even have to remove flywheel to inspect. There are a few nuts under flywheel that may vibrate off and cause this. Good luck!

Thanks for the great advice guys. I removed the recoil starter mechanism and it works smoothly and actually looks brand new under there. So that has been ruled out.

I removed the spark plugs and turned the motor over manually using the large bolt in the center of the flywheel. I was able to turn it, and I observed that the propeller spins along with the flywheel/crank in either direction I turn it. I also can see the pistons moving back and forth when I look through the plug holes. So that's all good progress.

BUT... it's still very hard to crank. I put the flywheel back on and cranked it over a couple times with the pull rope... it's still very difficult and I wonder why. Should I pour some sort of lube into the plug holes and let it penetrate for a while and try again?

It feels like it wants to turn over but there's just too much resistance.

 

[99yam40]

Re: Pull cord goes 6" and stops HARD - '94 Yamaha 15hp

I would open it up to see the cylinder walls and see what is happening. If it ran fine 3 weeks ago maybe there was water getting into it and caused some rust to form.

First drop lower unit just to make sure the drive shaft or lower unit is not the problem.

 

[kahuner]

Re: Pull cord goes 6" and stops HARD - '94 Yamaha 15hp

Could you be a little more specific when you say: "I can turn the motor with the large bolt in the center of the flywheel"?

Don't want to scare you but you could've siezed the engine when it was tested 3 weeks ago. You did put oil in the gas didn't you?

If you had to put ANY effort into to turning the motor over with a wrench with the plugs out, then it'll be VERY hard to turn over with the recoil starter. There's not much mechanical advantage.

With the plugs out, the motor should turn over without any effort.

Again, not trying to add any drama to your situation. Just want to rule out one of the possible causes.

 

[gettin'wet]

Re: Pull cord goes 6" and stops HARD - '94 Yamaha 15hp

Hey guys, again thanks for the attention. I've got it sorted out now. Took a better look and noticed one of the cylinders was clean as a whistle... probably steam cleaned by water in the cylinder. Further inspection revealed a ton of water in the carb and fuel system. It must have rusted up a bit inside the cylinders - exactly like you mentioned 99Yam40. I checked the gas tank and sure enough there was a lot of water in there too.

Sprayed a little penetrating fluid into the cylinders, loosened it all up. Drained the water out and flushed the carb and fuel lines with fresh gas. Emptied the tank and filled with fresh gas (yes blended with oil).

Started it up with a little starter fluid and let it run for 5 minutes in a tank. She's back to humming along as usual. Running great... and a good lesson learned... if you buy a used motor flush out the fuel system and dump the old gas FIRST THING.

Thanks again for all of your help guys!

 

[robert graham]

Re: Pull cord goes 6" and stops HARD - '94 Yamaha 15hp

Sounds like you got real lucky that the motor's running and not a whole lot of damage, apparently! Corrosion could have ruined that motor. Good Luck!