Johnson 150 running issues

jasoncooperpcola · #1 01-07-2012, 09:00 PM

Today i went to run my 1985 Johnson 150 on a 6 gallon tank with fresh gas and it wouldn't run below 1000rpm. If i turn the choke knob it will run rough below 1000 rpm. When i hold the carbs open a little it will crank and run beautiful. I try to run this motor once a month on fresh gas with stabil in a small tank but its been three months since i have run it. Tomorrow i plan to check plugs. What else should i check? I am beginning to think its a carb issue. I do not know when they were cleaned last. Right now i have adjusted the throttle cable out so it runs good. But i hate to cover up a problem by doing so. Anybody got any suggestions?

Also i have a 25" shaft Yamaha 150 2 stroke i may put on but need a remote control.

THEFERMANATOR · #2 01-07-2012, 09:12 PM

Pull the carbs and clean out the jets inside of it.

jasoncooperpcola · #3 01-07-2012, 09:22 PM

Would i need a chilton book for that? I haven't pulled the silencer cover off yet so i don't know what i am getting into. I cleaned/rebuilt all the carbs on the twin 150 Yamahas on the big boat. Is it pretty much straight forward like the yammies, where i can see the jets when i remove the silencer? Also would i need a rebuild kit with all the gaskets and such?

THEFERMANATOR · #4 01-07-2012, 09:24 PM

The jets that need to be cleaned will be inside the float bowls. If your careful you can normally re-use teh gaskets, but it is always a good idea to change them.

jasoncooperpcola · #5 01-07-2012, 10:15 PM

I just looked up a parts diagram for the carbs. The jets i am cleaning are #5 correct?

Destroyer · #6 01-07-2012, 11:53 PM

One thing I've found through the years is to always run any gas going into my engines through a fuel filter....even from a portable gas tank. I made up a portable fuel line that goes into a filter, and then the filter has the regular engine fittiing on the outflow side. I figure that a little protection is well worth the slight extra cost of the filter.

jasoncooperpcola · #7 01-08-2012, 12:35 AM

Quote:

Originally Posted by Destroyer

One thing I've found through the years is to always run any gas going into my engines through a fuel filter....even from a portable gas tank. I made up a portable fuel line that goes into a filter, and then the filter has the regular engine fittiing on the outflow side. I figure that a little protection is well worth the slight extra cost of the filter.

Good thinking, but i already have that covered. I hook my portable tank to the inlet of my Racor fuel filter. My main tank hasn't been hooked up since August!

THEFERMANATOR · #8 01-08-2012, 12:43 AM

Quote:

Originally Posted by jasoncooperpcola

I just looked up a parts diagram for the carbs. The jets i am cleaning are #5 correct?

#5 and #15 need to be cleaned inside as well as checking teh ports that go from #5 down to the bottom of the float bowl. And check #3 while you have it apart to make sure they are clean.

jasoncooperpcola · #9 01-08-2012, 12:45 PM

I took the top carb off this morning and was amazed at what i found. Both #15 was clogged with a thick green crap. The bowl has a puke greensih film in the botom and in the passages #5 to #15. How can i clean this plastic bowl without harming it. O'reillys had nothing that would work. After seeing this i am surprised the engine ran at all. I figured i would blow everything out with compressed air. So far i have #5 #3 #15 jets from the top carb soaking in cleaner.

Below is a picture of the bowl.

THEFERMANATOR · #10 01-08-2012, 01:15 PM

Quote:

Originally Posted by jasoncooperpcola

I took the top carb off this morning and was amazed at what i found. Both #15 was clogged with a thick green crap. The bowl has a puke greensih film in the botom and in the passages #5 to #15. How can i clean this plastic bowl without harming it. O'reillys had nothing that would work. After seeing this i am surprised the engine ran at all. I figured i would blow everything out with compressed air. So far i have #5 #3 #15 jets from the top carb soaking in cleaner.

They should be metal on an 85 150 as that is the old style cross flow engine. As for cleaners, I use EVINRUDE engine tuner in teh gallon jug to soak them. I also have an ultrasonic cleaner that I use if they aren't that bad.