1971 johnson 9.5hp

[Paul12]

I recently acquired a 1971 9.5hp Johnson. I was out running it today and I am having a few issues with it. I am new to 2-strokes so excuse me if I sound ignorant.

1. On the front of the carb there is a hole that faces towards the flywheel and when the motor is running fuel is spurting out. Is that normal? If not what causes it?

2. for about the first 10 minutes it ran, it seemed to run fine, then it started bogging down and would not obtain full rpm anymore. Ideas?

3. It does not want to run while the cover is on, but if I remove the cover it runs with above problems.

Do I need to rebuild the carb? If so where can I get the rebuild kit?

Picture below shows where hole that spurts fuel is. Kind of hard to see as I did it with Paint.
http://i32.photobucket.com/albums/d16/skredsvig82/IMG_18800.jpg

[budnate]

pull the carb and blow it out, make sure the float is ok and not sinking and set right. your gonna laugh but the hood needs a little vent hole drilled by the carb and it will run like a top...cant recall what happens exactly but it always does eventually with the pumpkin motors. they somehow wont run with the hood on, guys mount a vent angled down to keep the rain out, there good motors and peppy when sorted out .

B.

[Ifishwhisper]

No doubt the carb needs rebuiling! Seaway Marine in Seattle has your parts. The reason for the hood needing to be removed is that there is an exhust boot between the engine and the leg of the o/b and it is leaking and needs to be replaced. As it is the engine needs to run on air and is running/or not on exhust!
IFISHWHISPER

[Smj]

There's most likely a diaphram in there somewhere (carb or intake manifold) that acts as a fuel pump using the pulses from the piston. The diaphram may have holes in it, allowing fuel to go where it'e not supposed to(flooding/spurting out the vent hole). OR, the seat under the needle, or the needle, or both may be worn so bad that fuel just keeps pumping in even after the float bowl is full causing flooding/spurting out the vent hole. OR, BOTH. Or the float may have holes in it as mentioned.

If that motor's been sitting for a long time the rubber parts in it are most certainly toast. Upper and lower crank seals may be an issue, that'll give you funky idle that you'll have a tough time adjusting with the low speed mixture screw. New rubber pieces would be in order as just a bit of our 10% ethanol on old rubber would turn it to mush.

Curious what you find. A buddy and I used to cart an old motor like that up to (The famed) Strawberry Resevoir to hang on the back of the old flat bottom plywood boats in the mid seventies, fishing for trophy Lahontan cutthroat, bows and cuttbows.
Great memories.

Smj

[Paul12]

I took apart the carb and cleaned it really good. The cork float in the carb still had a shiny coating on it but the pin holding the float was dirty so i cleaned it up. The fuel pump diaphram was replaced right before I got the motor. I checked the exhaust boot and it looks fine. I am planning on replacing all the gaskets in the motor that I can. I looked around to find a new exhaust boot just in case all the places I have checked say it is no longer avaliable. It is leaking from somewhere though because when I run the motor with the cover off, exhaust is coming from soewhere under the cowling. Otherwise I pretty much ordered all new o-rings, gaskets, and rebuild kits for the motor. So after I install of them we will see how it works.

[saltfisher]

Hey Paul, nice motor. Them badboys will run forever if you take care of them. De3finately rebuild/clean the carb. Many times there is a piece fo foam at the carbs intake, make sure it isn't full of almost 40 years of crap. New fuel line for sure. If you want to get fancy, new plugs and wires. Other than that, that little beast will last a very long time. I jsut picked up 78' 7.5 horse for the trophy to use as a plan B. Keep me posted, I might be of more help once you clean everything etc. Also, drill a hole on the side of the coweling as said before, but use a pipe fitting to install an air cleaner from an remote controlled car on it. You can get the mini K&N filters. LOL

Bob



I took apart the carb and cleaned it really good. The cork float in the carb still had a shiny coating on it but the pin holding the float was dirty so i cleaned it up. The fuel pump diaphram was replaced right before I got the motor. I checked the exhaust boot and it looks fine. I am planning on replacing all the gaskets in the motor that I can. I looked around to find a new exhaust boot just in case all the places I have checked say it is no longer avaliable. It is leaking from somewhere though because when I run the motor with the cover off, exhaust is coming from soewhere under the cowling. Otherwise I pretty much ordered all new o-rings, gaskets, and rebuild kits for the motor. So after I install of them we will see how it works.