No power

[Johnson40]

I have a 40 horse Johnson 1985, it starts everytime, will idel and I can have it run in nuetral at full throtle. When I put it in forward it only goes about 1/3 speed. Whats wrong?
Jim

 

[Hoss the Hermit]

Re: No power

How do you know it's only 1/3 speed? Sounds like it's as fast as it will go with the setup you've got. That's full speed. Weight, hull config., prop all figure into the equation. Is it on a boat, or just turned loose by itself? Still tied to the dock? Maybe no oil in the lower unit? Running at full throttle in neutral is not a good thing. My thoughts.

 

[Johnson40]

Re: No power

at full throtle i am going 8 mph, normally before last weekend I would be going 23-25 mph. If I hold down the primer button I can get up to 23 mph, but if I press the primer and let it go and press and keep that up I get to 25 mph and it sounds normal. If I hold the button down it sounds like it is "bouging" out a little.

 

[Silvertip]

Re: No power

You have a fuel delivery problem and very likely it's a weak fuel pump.

 

[tashasdaddy]

Re: No power

either weak fuel pump, or clogged high speed jets in the carb.

 

[Johnson40]

Re: No power

How do I go about unclogging the fuel jet? Do I need to disassembel the carb?

 

[HighTrim]

Re: No power

yes the carbs need to be taken off and rebuilt with a bath. There is a special tool needed to remove the jets, or you can make your own as FR did here in the pic.



This video may help with your first carb rebuild.

http://www.meegsonline.com/tmd/TMDsVideoChronicle2.wmv

If you pump the primer bulb does it pick up at all? I would first guess fuel pump though, as TD and FR stated.

 

[Johnson40]

Re: No power

Believe it or not I just got to the motor and pulled off the Carbs. My top carb was full of gas and the bottom was bone dry, does this shed any light on my issue? I am getting the carb repair kits tomorrow.

 

[patrick4266]

Re: No power

I/m not a out board genius but i bet the needle valve is stuck on your dry carb

 

[Johnson40]

Re: No power

Makes sense, i thought it was the other way that the one with gas was the problem. (I run a printing press, what do I know) I looked at the dry one and found the point on the needle red, is that gunk, the wet one looked nice and clean.

 

[patrick4266]

Re: No power

sounds like it. You may be able to cean that neddle and jet and be fixed.

 

[patrick4266]

Re: No power

I just read where you are getting your car kits tomorrow. It would be best to rebuild them. If you would look at that carb rebuild video it will show you pretty much on how to to do it, and you can make that tool ,I did, from the pic from "hightrim" ,

 

[Johnson40]

Re: No power

one of the guys at work says I need a vacuum meter to set my carbs, what is he talking about?

 

[flabum]

Re: No power

Not true. besides, there is nowhere to hook them. Get the carbs rebuilt and istall them. do the link and sync as per the service manual and set the idle jets as outlined in the manual.