9.9 4 Strokes Doing Some Wierd Stuff....

[amsimonsjs]

Hello everyone!

I have a pair of 9.9 Yamaha 4 Strokes that were given to me. I am trying to get one running out of the two.

One is a 1991 and the other is a 1992.

I have one problem with the '91.

When I try and crank it over, be it by hand or with the starter, it only makes about half a turn and then it gets stuck.

What's weird is that it almost feels like a LOT of compression, beacuse I can force it to go a little more by hand.

I pulled the plugs, and I still get the same result.

And here's the strange part: If i turn it the opposite way, It turns over just fine!!!

The lower unit is NOT in gear, as I've triple checked that, so I have no idea what could be going on here.

These motors have been sitting for several years in a garage without running, so who knows what's going on.

Any Ideas??

Thanks in advance,

-Alex

 

[kandil]

Re: 9.9 4 Strokes Doing Some Wierd Stuff....

It sounds like a borking ring to me

 

[99yam40]

Re: 9.9 4 Strokes Doing Some Wierd Stuff....

Maybe the cam is out of time and the pistons are hitting valves or something under flywheel is hitting.
Might try dropping lower unit just to rule out problems with that

 

[amsimonsjs]

Re: 9.9 4 Strokes Doing Some Wierd Stuff....

Not too sure what's going on with this one, but I'm very hesitant to pull it apart as I fear that some bolts may break in the process. These motors have been sitting for a long time, so there may be a good amount of corrosion.

The other motor turns over fine. It needs the shift shaft connected above the lower unit, and a few electronics to be transferred over from the now "seized" motor.

Should I do some more diagnostic work on the stuck motor or move on to the other one?

-Alex

 

[jhosea1979]

Re: 9.9 4 Strokes Doing Some Wierd Stuff....

agree with dropping the lower unit but if it was the cam out of time it would not turn either way would it???

Maybe the cam is out of time and the pistons are hitting valves or something under flywheel is hitting.
Might try dropping lower unit just to rule out problems with that

 

[jhosea1979]

Re: 9.9 4 Strokes Doing Some Wierd Stuff....

i would move on to the one that does not lock up while turning it over

Best Of luck to ya

 

[amsimonsjs]

Re: 9.9 4 Strokes Doing Some Wierd Stuff....

Hi Everyone!

Was able to swap over all of the electronics, and she turns over fine and all, but I get no spark.

Since I have two motors, I can interchange alot of the parts. I tried swapping coils but that did nothing. I also swapped out the rectifier and the cdi unit, and I still get no spark.

Where should I start troubleshooting this problem?

Thanks!

 

[99yam40]

Re: 9.9 4 Strokes Doing Some Wierd Stuff....

pick up a service manual for your motor and it will tell you what to test, how to test , what equipment to use, and what the specs are

 

[Big flop]

Re: 9.9 4 Strokes Doing Some Wierd Stuff....

Is the kill cord (lanyard) hooked up
on the front of the motor?

 

[amsimonsjs]

Re: 9.9 4 Strokes Doing Some Wierd Stuff....

The kill wire is disconnected. I have made sure the kill wire is not receiving ground. All other wires are hooked up properly.

I've tired swapping everything but the stator.

Any other ideas?

-Alex