2001 johnson 150 ocean pro bogging down at 4400 rpm

[ahmincha]

As stated I have a 01 johnson 150 that has a little hiccup miss at idle. runs strong thru 4400 rpm then bogs down to nothing never actually stalls then will recoup and run strong again. has all new fuel lines and water separator, also has a electric fuel primer

 

[hunter200524]

I'm horrible at remembering which years have which, but I'm pretty sure this uses plastic carbs. If so first thing I would check is to make sure the main jets havnt come loose. You can remover the drain plug and put a flathead screwdriver in the hole and see if you can turn the jet in any more turns. If not they could have warped float bowls. Of course thats just a place to start after you check spark and compression.

 

[Chris1956]

Check the fuel tank vent as well. At high RPM you need more air venting the tank. Loosening the tank cap is an effective test.

My '98 Johnny 150HP has those plastic carbs, but I have not had any issue with them. The motor runs terrific. It used to idle a bit poorly, but I was able to clean the idle orifices with a bit of carb spray cleaner. That helped a bit.,

If that doesn't fix it, you may need to rebuild the carbs.

 

[bob johnson]

they made some ocean pros that were FICHT, they even made some Johnson motors in FICHT!!!!!!!

so does this motor in fact have carbs???

bob

 

[ahmincha]

Thanks guy's for the replies Yes this is a carbed motor I did change the small inlet filter today as it was pretty dirty. I was not able to test it today lake was to rough I will update. I did ck spark and all cylinders and at idle they all have spark

 

[ahmincha]

I also realized that 4400 rpm is max I'm getting. I have not ck my prop size yet . but I do know motor is small for boat.

 

[Chris1956]

OK, what size and type of boat, and what prop do you have?

 

[ahmincha]

Its a 1992 stratos 2250 wa weighs 3000 pounds I have to get the prop size

 

[ahmincha]

Prop is 15x17

 

[Chris1956]

Gee, I would think that prop is OK for that boat/motor combo. I run a 19P prop on my setup which is similar to yours, and it is a bit overpropped. I would think the 17P prop you have should be very close to correct.

Check your compression, and see if you can fix whatever fuel issue you have. I think you have a supply problem. You might remove the anti-siphon valve and open the fuel tank vent to eliminate those two fuel restriction issues. Make sure the main strainer under the airbox is clean and the gasket and O ring seals well.

 

[ahmincha]

Cyl 1. 110
Cyl 2. 108
Cyl 3. 107
Cyl 4. 113
Cyl 5. 114
Cyl 6. 115
I am assuming compression is good

 

[Chris1956]

Compression looks good to me....

 

[ahmincha]

The only fuel line I have not replaced on the boat is the one with the ball for priming the motor. I am going to replace it this weekend and see if that helps. Will report back And thanks for your help

 

[ahmincha]

Ok little update. took boat out today It maxes out at 4400 rpm will run there for a while 4 5 min then it will bog down to 1000 rpm. at that point if i put it neutral and rev it goes right up. put it in gear and on our way. Back to 4400 max.
Also noticed hit a wave hard and immediately bogged down to 1000. same procedure as above to recoup.
Next thing I noticed is in reverse it has a bad miss that's not noticeable in forward.
And finally my binnacle trim switch was bad motor would lower on it own. Bypassed that with a momentary switch been working for last few weeks now I have to disconnect the trim switch on the motor for the same reason. My question is this a common occurrence with theses motors
Thanks again for the help
I cked for loose grounds and wires and thinking maybe a power pack

 

[Chris1956]

OK, shift assist switch could be causing miss in reverse. Loose wiring could cause your other issues. I would disconnect shift assist switch and overheat sensors and see if things improve. Reconnect after test, as disconnect is not the cure....

Also look for wires that lost insulation, especially black/yellow and black/orange wires.

 

[ahmincha]

Well never really did anything special to fix motor but has not bogged down on my last 3 trips out actually ran very well.
Still max rpm is 4400 but I figure it a little undersized for the boat