Johnson 33hp isnt running or starting good?

[matt9923]

I had it running up to 1/2 throttle yesterday so though it maybe needed a carb cleaning now it wont start easy. I pull it 5 times and then it randomly starts. Its getting a great spark, new coils points ext... all new electrical. Now as i adjust the low speed needle it pops and makes a air smoke release from the leaf valve area while running rough. Not exactly sure. The needles look all chewed up and i sanded the scratches lightly sp they don't screw up my carb.
Could this be leaf valves, carb? I don't know where to get leaf valves, new carb, carb needles. So i don't know what to do? its something mechanical not any adjustment. i tried adjusting everything adjustable and i had them set to factories settings. Anyone know what this is? i have no clue at this point iv never had this problem with a motor before?
Matt

 

[steelespike]

Re: Johnson 33hp isnt running or starting good?

You described a lean sneeze.
More than likely the carb needs a rebuild with careful attention to cleaning
all passages and jets.If it has sat a lot over the years a careful inspection of the fuel system from tank to carb is a good idea.Be sure the tank vent is open and clear.

 

[matt9923]

Re: Johnson 33hp isnt running or starting good?

You described a lean sneeze.
More than likely the carb needs a rebuild with careful attention to cleaning
all passages and jets.If it has sat a lot over the years a careful inspection of the fuel system from tank to carb is a good idea.Be sure the tank vent is open and clear.

Cleaned fuel tank. new pump hose. cleaned fuel pump. I cant fined the right parts to rebuild the needles i did find the high speed for 40$. wow BS.
I don't know what to do but ill try something. nobody around hears works on these old motors.

 

[freddyray21]

Re: Johnson 33hp isnt running or starting good?

a carb kit will have all the parts needed but no needle valves. Those can usually be cleaned just fine unless someone really messed them up.

 

[matt9923]

Re: Johnson 33hp isnt running or starting good?

a carb kit will have all the parts needed but no needle valves. Those can usually be cleaned just fine unless someone really messed them up.

It seems like the bushing they ride in is messed up they have turn scratches on them and the high speed has thread marks. I can see where someone gone around those motor before idk what they did to it. Its my first outboard and idk about some of these and haven't had any problems like this before. I work on this stuff all the time but this is giving me hell.
Matt

 

[jay_merrill]

Re: Johnson 33hp isnt running or starting good?

Your motor is backfiring and one of the causes of that is a lean condition, due to carburetor problems. You have already said that your have damage to the needle valves, so those will need to be replaced. Another common reason for carburetor related backfiring, is air leakage around the packing nuts on the needle valves, and/or around a worn throttle butterfly shaft.

The needle valves for this motor are no longer available from BRP, but some dealers might have them remining in stock. If so, you'll probably pay a high price unless you have a long standing relationship with your dealer. Mine sells me NOS items at low prices, because I buy a lot of stuff from him, and he would be just as happy to get rid of it. That said, I have been doing business with him for ten + years.

Another avenue would be to buy a used carburetor at EBay or a similar site. Carbs for any of the "non-Superquiet" models of the late fifties 35hp motors, to the early sixties 28hp motor, to your model (33hp) will work. The carbs on the Superquiet models (fat midsection) are different, and as far as I know, won't fit your motor. If I were in your shoes, I would go with the used carb and rebuild it - there is no sense in burning up a lot of time trying to find individual needle valves.