89 johnson 40hp vro loss of power

[andyhou]

I'm really bazzled by this, my motor lost all top end power and idles pretty rough if at all. The only thing that i did was spray some carb cleaner in there and it ran well for that day. I took it out the very next day and it has no power at all, i could start it and put it in gear really fast and it will run at a very low speed but if i try to accelerate it just shuts off. It almost seems like it might be running too rich? Any suggestions would be greatly appreciated. Also does anyone know if my carb has a high and low adjustment screw and where it is located? Thanks in advance.

Andy

 

[tfbrown1270]

Re: 89 johnson 40hp vro loss of power

HI Andyhou; I HOPE that the carb cleaner you sprayed in there was for two cycle engines, I believe that carb cleaners designed for four stroke engines will (just like they should) strip the lubricant off the rings, bearing etc...not a good thing. With any luck you used a 2 stroke cleaner (like Seafoam or one of the other proprietary products).
If you used a 4 stroke product and especially if you used a lot of it I would suggest a compression test to see if the rings are toast, if you used a 2 stroke product I got no ideas for you...

 

[tashasdaddy]

Re: 89 johnson 40hp vro loss of power

what have you done to trouble shoot. have you checked spark, compression, fuel delivery. there are a lot of thing it could be. spray carb cleaner could have freed up crap in the carb. when last cleaned and rebuilt. could be coils, or electrical heating up an failing. could be fuel pump is bad. check spark and compression, they're free to check. also does you tank have a vent. was it open. do you have built in tank, or portable?

 

[andyhou]

Re: 89 johnson 40hp vro loss of power

tfbrown1270
The product i used was for four strokes, although i didn't use a whole lot of it. Do you think carb adjust might help me at all?
thank you,
andy

 

[andyhou]

Re: 89 johnson 40hp vro loss of power

tashasdaddy,
I unplugged each plug and it stilll fired right up, I didn't check compression yet. My gas tank is a 7 gallon portable and the vent is completely shut.
Andy

 

[tfbrown1270]

Re: 89 johnson 40hp vro loss of power

if you didn't use much then the chances are it's not responsible for the problems, however, like tashasdaddy suggested it may have knocked some crap loose, since there is only one carb it would be easy to remove it and clean it up. I would however start with the basics like td suggested.

+++ I just read the last line...that tank needs to be vented, open the lid enough to let some air in..if air can't get in then gas can't get out....might be as easy as that.

 

[tashasdaddy]

Re: 89 johnson 40hp vro loss of power

the fuel pump can't suck gas with out a vent. the tank becomes a vacuum. you should check compression atleast annually, could tell you if you have problems, before they are totally outrageous to fix.