caurberator rebuild mistake

[ifishy]

okay so I have a 1966 40hp johnson I have had it for 7 years it was running fine untill late this year. After some research it seemed like it was a caurberator. I have been using gas with ethanol and not treating it which was probably a mistake. I bought a rebuild kit online and looked up directions many of which I got from this site. I was able to finish the rebuild without incedent and did not have any left over parts. when I reattached it to test and adjust it I couldnt start the moter and when i pump the primer bulb on the fuel line gas comes pouring out of the front of the air intake as well as a hole to the upper right of the intake. What did I do wrong and how do I fix it. The only thing I can think of is I set the float wrong or something. I was definatly feeling overconfident after what I read about outboard carbs being doable for a non mechaninc with just some mechanical ability. given the age of this motor and my budget a professional rebuild is not really an option. Please help

 

[1946Zephyr]

Re: caurberator rebuild mistake

Yea, I had this same issue earlier this year with an older 35. All you need to do, is remove the bowl from the carb and on the rear of the float, you'll see a small tab that pointing straight up. With your float at the closed position, bend that tab in towards the inlet that your needle assembly screws into to where you have a smaller gap. This will allow your float to drop enough to open your needle. The tip of your float only needs to drop 1/2 inch. If they drop too far, then they can't shut the gas off properly and gas will run out the front.

 

[boobie]

Re: caurberator rebuild mistake

That's called setting the float level properly. Both level and drop.

 

[1946Zephyr]

Re: caurberator rebuild mistake

Yep, these big twins love to puke gas out the front, if the drop level is too low.

 

[ifishy]

Re: caurberator rebuild mistake

thanks for the help I will hopefully find a time during the week to pull it off and readjust it is there any way to check that its set right without re-attaching it to the motor? its behind the starter assembly so it takes a while to get it on and off and its tough to do in the dark. by the time i get home the sun is down so I mostly work on it on weekends. the season is short I was hoping to get a test drive in before i winterize it but if I have to wait till spring I will.

 

[1946Zephyr]

Re: caurberator rebuild mistake

Well, you will have to remove the carb. Getting to the bowl screws would be a pain in the rear unless you do so, but you can check it, before you mount it back on. Just attach the fuel line back on and hold the carb in the upright position and prime it up. This should be good enough to see if gas runs out again.

 

[boobie]

Re: caurberator rebuild mistake

You have to have the carb off of the mtr and disassembled to set both the float level and drop. Float level is measured with the carb upside down. Float drop is measured with the carb in upright position. Specs are in the service manual.

 

[Silvertip]

Re: caurberator rebuild mistake

The way to verify if the float is closing and opening properly is to first tip it upside down with the bowl removed. Blow (by mouth) into the fuel inlet fitting. If air passes you did it wrong. If it seals, tip the carb upright and repeat the test. It shoud then pass air. If not, you have the drop set wrong.

 

[lindy46]

Re: caurberator rebuild mistake

I usually adjust the float arm so the float assembly is a little short of parallel to the carb body when the needle is in the closed position (float up). Sort of hard to describe, but you want the needle to close before the fuel level gets too high in the bowl. You actually have to do the adjustment with the carb upside-down, and in this position, the float assembly angles up ever so slightly from parallel. If you bend it too much, the bowl won't fill enough.

 

[ifishy]

Re: caurberator rebuild mistake

thanks for the help the directions in the kit said to set it parallel I did not get home till late tonight but I'm hoping for wensday to get it off the mtr and into my work area I'll check back in but its nice to have this resource on the web for us low budget fisherman who just want to keep a boat on the water way past its prime.

 

[1946Zephyr]

Re: caurberator rebuild mistake

Most of all, set your float drop level correctly and you'll be good.