johnson cd17 runs a little hot?

[Flyers-R-Diers]

ok. i have had this motor in the shop last year and it had plenty of work done to it. guy says he put a new impeller in it but the motor still runs hot and acts like it is runnin short on power. still pushes my 14' aluminum boat ok but not too fast. is this normal. also it seems to run better with the hood off even though it is water cooled. what could be wrong?

 

[F_R]

Re: johnson cd17 runs a little hot?

The impeller is only part of the water pump. That won't cure a worn pump housing.

Thermostat could be shot

Water passages could be clogged

Is it tight, like about half way froze up? Shock absorber in lower unit could be broken, accounting for lack of power.

Could be running on one cylinder if lack of power is like only half speed.

OR, maybe you are just expecting too much from a 5.5.

 

[Flyers-R-Diers]

Re: johnson cd17 runs a little hot?

that may be. i was watching some videos on youtube of the same motors with new impellers and water pumps runnin and looks the same. but motor does like to run a little higher (sound wise) without the hood. runs fine otherwise.

how fast can a 5.5 be expected to go with a 14' boat and only 200 lbs max to push?

 

[Flyers-R-Diers]

Re: johnson cd17 runs a little hot?

ok i ran the motor out on a lake today on a test run. it ran fine except for every 10 minutes or so it would start to die at full throttle. so i shut it down and re-started it after a minute or less. then it ran for a while just fine. but did the same thing again after another 10 minutes or so. it also still seems to like it better with the hood off. it doest run as long and seems to have less power with the hood on it. what could this be and what can i do to fix it?

or does my motor have a mind of its own?

 

[F_R]

Re: johnson cd17 runs a little hot?

Sorry, I can't relate the stop-running to the hood. An exhaust leak under the hood can affect power though.

10 minutes is a long time to run before trouble appears. And restarting within a minute suggests that you are getting insufficient fuel flow to the carburetor. When it starts to die, can you keep it going by squeezing the primer bulb? Also, try running it with the gas cap loose. It may not be getting air into the tank to replace the gas that is being drawn out.

Just educated guesses.

 

[Flyers-R-Diers]

Re: johnson cd17 runs a little hot?

ok thanks. i'll try that. it didnt stop because of the hood but seemed to slow down and struggle a little more with the hood on vs the hood off. i have a feeling im just expecting it to push too much and that would make it seem to be runnin low on power. its only a 5.5.