1999 Johnson 9.9 went from WOT to Half throttle to dead any ideas?

[putzee52]

My 1999 Johnson 9.9 ran great and trolled for about 3 hours. Then on the way back to dock it was running full throttle out of no where it choked down to half throttle, then close to the dock when i slowed it down the motor died and would not restart.
Took it home it started in the driveway then died and would restart.

Any ideas? It seems wierd the motor would die like that.

The primer ball was hard.
I just swapped out the lower unit seals and waterpump before this trip.

Any help would be great.

 

[nwcove]

Re: 1999 Johnson 9.9 went from WOT to Half throttle to dead any ideas?

how was the tell tale looking at wot ? sounds like the symptoms of an over heat or ignition problems.

 

[Daviet]

Re: 1999 Johnson 9.9 went from WOT to Half throttle to dead any ideas?

I would start by checking the spark and compression.

 

[putzee52]

Re: 1999 Johnson 9.9 went from WOT to Half throttle to dead any ideas?

I took it to the shop. The overheat alarm went off a few times in the past at idle which is why I did the water pump change. While dropping it off I noticed a brown oils coming from the exhaust in the prop. I also remember when on the water Friday the volt meter on my dash spiking near 16volts which usually rides around 14v

 

[putzee52]

Re: 1999 Johnson 9.9 went from WOT to Half throttle to dead any ideas?

The shop just called. Apparently one of the reed valves has broken.

 

[Rudemen]

Re: 1999 Johnson 9.9 went from WOT to Half throttle to dead any ideas?

Oops, hope one of the cylinders didn't get trashed. I have my fingers crossed for ya!!!

 

[putzee52]

Re: 1999 Johnson 9.9 went from WOT to Half throttle to dead any ideas?

Yeah big opps. LOL explains the extra oil out of the prop.
I too hope the cyinder is still in good shape, i guess there is a chance it is fouled up though. I was on the water when the motor went to half power and still had a bit to get to the dock. My fingers are crossed.

 

[putzee52]

Re: 1999 Johnson 9.9 went from WOT to Half throttle to dead any ideas?

Turns out the reed never broke there was debris preventing it from functioning. $350 for new manifold gaskets and out the door.

 

[mchrist809]

Re: 1999 Johnson 9.9 went from WOT to Half throttle to dead any ideas?

My 1999 Johnson 9.9 ran great and trolled for about 3 hours. Then on the way back to dock it was running full throttle out of no where it choked down to half throttle, then close to the dock when i slowed it down the motor died and would not restart.
Took it home it started in the driveway then died and would restart.

Any ideas? It seems wierd the motor would die like that.

The primer ball was hard.
I just swapped out the lower unit seals and waterpump before this trip.

Any help would be great.

Resolved thread here, I know, but for the next guy looking at this...

I experienced something very similar recently on my '96 9.9. Turned out it was just an old emergency shut-off key, which wasn't seating properly. Jiggle this way, spark. Jiggle that way, no spark. 25 cent fix. Something to check first if anyone experiences sudden/intermitent loss of power. (And brown leakage was merely unspent fuel-oil draining out after sudden power loss.)