Water circulation issue 1983 9.9hp Johnson, Long Shaft outboard

[stuarth]

I have a 1983 9.9hp Johnson, Long Shaft outboard (J10B1LCTR)
The peehole sprays lots of water when running and it is not much warmer than the water in the lake so I trust my water pump is OK.
The other hole (overboard?) which is at the top of the propeller shaft pumps out exhaust gas and some hot water after a short while running but I also have hot water dripping into the motor housing and dripping out underneath the housing.
I can't see where it is coming from but I suspect a pipe is split.
Any pointers or ideas please?

thanks

[boats.net]

Could be a leaking gasket, a hole in water hose, its hard to say. Remove cowling and check for leaks with engine running.

[stuarth]

I suspect a gasket since I can see no water leaking from the pipe going from the block to the peehole so I think I will remove the thermostat housing and also change the thermostat. Are there any nasties I need to be aware of when I do this?
thanks

[boats.net]

No, thermostat is easy to change.

[stuarth]

Thank you. I am a bit concerned the bolts wimm be seized or shear so I will give them a gentle heating with a blowlamp and some WD40 or brake fluid

[boats.net]

That's a good idea.

[stuarth]

Anybody know where I can find part numbers for the thermostat and the joint to the cylinder block?

[stuarth]

Turns out that the bolts were not tight at all and came out with no effort. Getting the thermostat housing out was another matter though it can be done without removing the case catch - you just need to press hard to compress the spring.
Finding the joint I need is proving difficult. Is it OK to just use jointing compound (the blue silicone stuff)? The thermostat is hard to find too

[stuarth]

can I post pictures here?

[boats.net]

Yes silicone sealant is ok to use. Click on the camera icon on top your post to add pictures or click on add attachment icon..

[stuarth]

OK; Gasket changed and indeed it seems it was leaking and now doesn't.
However, whoever designed the catch for the top cover should be sacked. It is impossible to refit even though logically if you can get it out you can get it in. ANnd why is the cover such a weird shape with bolts all over except on one corner?
It runs ok but I don't seem to be able to rev it up as much as before and I also suspect a fuel leak. The pipe which runs from the fuel connector to the carburettor is some tough looking rubber. Can this be replaced with, say, clear plastic or would it melt?
thanks

[stuarth]

The motor starts easily and runs OK but there are two odd signs. After about 5-8 minutes the motor slows down temporarily and after a minute will run up to speed again but in any event it does not rev very high.
If I put the engine in gear however, it revs much better and much higher!
Any ideas please??

Thanks

[boats.net]

It has a throttle stop when in neutral to keep engine from over revving, when in forward gear it would be able to run at wide open throttle. If rpm's increase and slow down at same throttle position then may have dirty carb. may need to remove and clean carb.

[stuarth]

Excellent! Thank you very much for the reply!