90 johnson running hot

[davcr59]

I have recently purchased a 90hp johnson loop charge and it runs hot. I removed the lower unit and flushed the engine with a hose from the tattel tale and comes out of the pipe that connects to the impeller housing and a smaller hole about 3 inches away I do not understand why the water is coming out of this smaller hole and could this be the problem. With the engine running a large amount of water comes out between the midsection and the lower unit. And hardly any from the prop. I would greatly appreciate any help.


Thanks

 

[daselbee]

Re: 90 johnson running hot

From your own words..."With the engine running a large amount of water comes out between the midsection and the lower unit."
This tells me you are ruunning on muffs.
Try it in a garbage can filled deep enough to cover the water pump.
Muffs can add turbulence and air to the input causing impaired WP operation.
Also, if the L/U is still off, you can use a piece of 5/8 in water hose and clamp it directly to the water tube in the midsection. Turn on the water, and see if it overheats then.

 

[tashasdaddy]

Re: 90 johnson running hot

change your impeller if you have not.. check your exhaust housing gasket midsection to lower unit. grommet to water pump to water tube, do not pinch grommet when installing. also could have tried tstats, or deflectors, in the block.

 

[davcr59]

Re: 90 johnson running hot

I just ran the engine with the water hose connected directly to the water tube and it did not overheat it must be the muffs/impeller I will order the impeller kit from iboats and changed it. I let you know how it turns out.


Thanks

 

[daselbee]

Re: 90 johnson running hot

It wouldn't surprise me a bit if you changed the impeller, put it back on the muffs and it still overheated.
Muffs have always given me very different results from different engines.
But submerged, with the WP covered like it is designed to run, is very consistent.

I don't use muffs anymore.