Yamaha 9.9 overheat problem

[stevegardner]

I have a 2001 9.9 long shaft. Late last year I noticed the water wasn't peeing out as good as it should. I took it in to the shop and had the motor winterized, serviced and impeller changed out. When I got it back, the old impeller looked pretty good but they said it doesn't take much to screw them up. After I fitted the motor back on to the boat, the water circulation wasn't any better than before. I opened up all the lines and stuck a weedeater thread down and didn't find any blockages and could blow air down OK. I finally pulled the motor up and put the muffs on. I could see water pushing out around the flange where the leg bolts on to the lower unit. Its probably about 1/3 of total flow, this is why the pisser isn't looking right. Is there a gasket that they missed when they put the motor back together, or some alignment problem with the water tubes?

 

[n6rfm]

Re: Yamaha 9.9 overheat problem

many possibilities come to mind including
- lower unit not properly mated
- impeller vanes in pump set in wrong direction
- leak in water pump housing
- leak in gaskets for water pump housing
- poorly aligned or cracked tube which mates to top of water pump and delivers water to head/block. this needs to be lined up correctly before re-assembly.

It is not hard to examine/repair yourself. IMO, the repair manual is a must.
or take it back and insist they fix it properly; that's why credit card bills can be disputed.

mine had poor flow for the reasons three and five.

bob

 

[Mas]

Re: Yamaha 9.9 overheat problem

On muffs, you're going to get water blowing out in all different directions. Hose pressure is usually too much. To really test, you gotta submerge the leg in water and let the pump pump and monitor head temp.

MAS

 

[stevegardner]

Re: Yamaha 9.9 overheat problem

Bob: Thanks for the info; I got the motor off the boat and am going to take it back in to the shop.