1984, 150hp Help Please

[joeyd50]

My son blew up a 1994 150HP Johnson, he replaced it with a 1984 150 Johnson, very clean and of course the guy said it ran great, it idles fine it ravs up fine but under a load it boggs down and won't plane.I had a 85hp and my son had a 115with the same problem. I rebuilt the carbs on the 85 and the 115 and solved the problem, it was the hi speed jets, the 150, I didn't rebuild the carbs, did pull the hi speed jets and they were clean.
Thanks
Joe

 

[tashasdaddy]

Re: 1984, 150hp Help Please

you have 6 jets in each unit, 3 jets for each cylinder. low in the upper 1/2, high behind the drain plugs, and intermediate, in the recess of the bowl bottom, most people miss these intermediates. and miss cleaning the pickup tube that go to them. look at diagarm of the carb here

http://shop2.evinrude.com/ext/index.aspx?s1=86d3d72aeba35dacbc349b439cb45104

 

[James R]

Re: 1984, 150hp Help Please

A complete thorough carb cleaning job is essential or this motor could blow also. Low fuel supply means low lub on a two stroke.
I have just completed rebuild on a second 150 Johnson, both 1993 models, but much the same as the 1994. Do you have any idea why your Johnson failed?

 

[joeyd50]

Re: 1984, 150hp Help Please

I'll have to take a better look at his carbs, I don't know exactly way the 1994 failed, I know he was told he blew a piston, and when taking the 94 off his boat pieces of metal were fallen out from under all that plastic, I don't know from where, we never removed any plastic to see. Still have the 94, I told him he should get it rebuilt.
Thanks Guys
Joe

 

[emdsapmgr]

Re: 1984, 150hp Help Please

The engine could be dropping spark on a cylinder. Check the spark when the engine is under load.

 

[jonesg]

Re: 1984, 150hp Help Please

The engine could be dropping spark on a cylinder. Check the spark when the engine is under load.

YEh , why assume its the carbs again, it might be ignition.

 

[tashasdaddy]

Re: 1984, 150hp Help Please

why assume it is the carb again? the intermediate jets is located in the bottom of the carb bowl, and get missed by many, if it cannot get the fuel thru it, you have the exact, situation, he has described.
failed spark you would notice at idle.

 

[joeyd50]

Re: 1984, 150hp Help Please

I like to thank everyone for there help, my son put it in the shop.
Thanks Again
Joe