Johnson 150hp 1999 J150PXEES

[khorton2911]

I have a boat and it does not seem to have the correct prop on it. I am only running 4200rpm and this is going with the wind. The boat is a 22' Bay Stealth center console. I think I should be running around 5000-5200 rpm. If I troll around at 4 mph it has gotten the engine hot a time or two. So I am assuming the engine is working too hard to turn the prop. Currently, it has a 19 pitch 14.50 prop on it. Any suggestions? Boat weight is about 2200lbs.

 

[racerone]

Have you looked at / replaced the water pump impeller ?-----Top RPM will change if there is something wrong with the motor.----Seeing it has overheated at idle ( warning sign ) it is now time to do a compression test.----Mixing at 50:1 or is oil injection in service ?----If in service has oil injection system been tested and inspected.----How did this machine run for you last season ?

 

[khorton2911]

Have you looked at / replaced the water pump impeller ?-----Top RPM will change if there is something wrong with the motor.----Seeing it has overheated at idle ( warning sign ) it is now time to do a compression test.----Mixing at 50:1 or is oil injection in service ?----If in service has oil injection system been tested and inspected.----How did this machine run for you last season ?

Since I have had the boat it has not reached the correct RPM. I had some steering repairs done and the mechanic put this 21 pitch prop on because I was only getting 3800 rpm when I bought it. I can get a new impeller put in. It seems that I am getting a good stream of water. I am mixing at 50:1. I will have to get a compression test done since I don't have the tool to do it. I have never had it get hot when running wide open or even at a moderate clip. It has only happened when running 4 mph or less.

 

[racerone]

Why would a mechanic put on a prop with that much pitch if you were only getting 3800 RPM ??-----There is something wrong with the motor.----Compression test and spark test.-----Could be running on 4 or 5 cylinders !

 

[khorton2911]

Why would a mechanic put on a prop with that much pitch if you were only getting 3800 RPM ??-----There is something wrong with the motor.----Compression test and spark test.-----Could be running on 4 or 5 cylinders !

In his defense, I brought the boat in to have the steering cables replaced since they were bad when I bought it. It was a bit of a project boat. He noticed the prop was a bit chewed up and he asked what RPM I was getting and I told him only 3800. He had the 19 put it on and asked me to tell him the RPM next time I used it. I did, but since the boat was not in front of him he hasn't gotten back to me.

I have now ordered a compression tester and should have it tomorrow. I will test the compression and let you know.

 

[khorton2911]

Ok, did my compression test tonight. I am getting 68 - 72 psi. This is after about a 5-8 minute idle.

 

[racerone]

Test with another gauge.----You have a bad gauge or something is wrong with the motor.

 

[Schinner36]

I bought a johnson 9.5HP outboard, for $175 and am excited to put it in the water next week. The person I bought it from started it right up and My step-dad (who knows a little about motors) took a look at it and said he believed it was good to go. I am trying to find an owners manual or service manual for it and am having trouble. the model number appeared to be MO or MQ -13M. all I have been able to get from that it is probably a '67 the serial number I read is J2726111 I haven't found anything useful based on that. Additionally are there any issues I should be aware of for this motor. Finally this is a 2-stroke 50:1 what brand/type of oil would you recommend? Thank you all for all your help

 

[khorton2911]

Test with another gauge.----You have a bad gauge or something is wrong with the motor.

Ok, finally got another gauge and yes I had a bad gauge. All cylinders tested between 88 and 90 psi. Which according to the motor spec should be correct.

 

[khorton2911]

@racerone did you have a prop suggestion?

 

[Ray74]

Do a spark test as suggested. Doesnt sound like its running on all 6 cylinders. Start it up and let it idle. Pull one plug wire off at a time and listen for a change in the rpms. If you pull a wire off and sound doest change thats a dead cylinder. Could be the carb or the coil.

 

[gbigfish]

Am running

Johnson 150hp 1999 J150PXEES i am turning a 15x17 aluminum three blade prop, 21 foot boat WOT am turning around 5300 RPM with the boat trimmed out, 43 MPH​

 

[Ray74]

Mercury enertia 15.5x17