65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

[Hef A]

I took apart my carb to clean and rebuild last night and found 1 of the 4 bowls full of heavy corrosion. Its red like rust but looks more like battery corrosion. What would cause this? I would like to fix ithe problem, not just clean and put it back...

 

[Hef A]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

So water had to get into just this one barrel, would that be a head gasket problem?

 

[jonesg]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

Looks like the carb gasket wasn't right or something but where did all the water come from, don't know, lets bump it back to the top.

 

[Hef A]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

thanks for the response... I havent done a compression test yet, but my only thought was the head gasked, but I really dont know. Also, what are those parts in the picture that screw down opposite of the bowl & float?

 

[rolmops]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

Your head gasket is on the other end of the motor,as such it is not a probable cause for your problem.
What may happen is that the feed hose for this carb is at the bottom of the cluster and when water condenses in the system it gravitates toward that bowl.
Another reason may be that the carb is clogged and no fuel has gone out of it for a long time causing the fuel to evaporate over time and leaving other residue behind while being refilled every time you run the engine.
My guess is that you should do a very thorough cleaning of the carbs,and make sure that the passages specially in the rusty one are open and clean.That should solve the problem and give you additional power.

 

[Hef A]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

that bowl being clogged seems like the probable cause. There is no rust or corrosion anywhere else in the carb. If no fuel has gone through that bowl, then no oil has gotten to that cylinder either. Would that cause a problem if its been run with one cylinder dry? I've run it for over a hour trying to clear the carb etc. and have no idea how long before I got it.

 

[bluefire91]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

I agree with you on this one Hef. I had a small Homda 400 twin, and the float valve was stuck on it. Inside the carb was the same sort of rust color, and completely dry inside. I unstuck the needle, and BLAM! It ran twice as fast, who'd have thunk it!!

I'd check the float valve needle, and clean any deposits that might be causing it to stick, and you should be just fine!!!

 

[Hef A]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

one question about the float valve needles. 2 are hollow with a spring and metal tip in the valve needle - 2 are solid (no spring) this doesn't seem right. Should they all have a spring or all be solid?

 

[Hef A]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

bump

 

[bluefire91]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

Hef, I would say, likely not. I have pulled a parts drawing of the 4 carb assembly from 1968, and found the same part number listed for all 4 needles. However, I'm looking at a 4 carb set up from 1968, and you're working with a '65. I'm afraid I probably haven't answered much for you, but here's where I found the drawings from the carbs most similar to yours.http://www.boats.net/parts/search/BRP/JOHNSON/1968/V4TL-14B%201968/parts.html
Click on the carburetor group..

 

[McGR]

Re: 65 johnson 90hp Carb rebuild - 1 bowl full of red corrosion

I wouldn't get terribly caught up in the "why it happened" right now. I think if you cover several bases you should be in good shape. Proceed as follows:

1. Thoroughly clean and rebuild the carbs. Get all of that crud out !
2. Replace any old/questionalble fuel lines.
3. Disassemble and clean your fuel pump. Replace/rebuild if necessary.
4. Check your fuel. Make sure there is no water in the tank.

If you cover these thoroughly your fuel system will be ready to go.