Rebuilt carb... Now won't start.

[55'Fleetwin7.5]

Re: Rebuilt carb... Now won't start.

What depth are you making them?

 

[freddyray21]

Re: Rebuilt carb... Now won't start.

just a bit thicker than it take to cover the jet. The hose needs to be small enough to fit tightly on the needle.

 

[55'Fleetwin7.5]

Re: Rebuilt carb... Now won't start.

My current washer does not cover the jet... about 1/32nd shy.

 

[freddyray21]

Re: Rebuilt carb... Now won't start.

that might be the problem. I know cut them oversized, but I have had a lot of problems with air sucking there so I tend to go oversized. The jet actually sits down in the wheel in the bottom of the bowl so it does not need to be as thick as I make them, but it does need to seal off well enough to keep it from sucking air or too much gas. The high speed needle goes in that well too and controls your fuel mix keeping just enough, but not too much in there. Too much and it can flood and not enough and it starves for fuel at wot and won't wrap out.

 

[55'Fleetwin7.5]

Re: Rebuilt carb... Now won't start.

I have investigated this further and cannot find any mention of this "Boss" washer on the high speed jet anywhere in my manual. I do not believe there was one when I started. The Sad net result is that I am still flooding (gas spitting out from the choke plate area) and not firing. The really frustrating part is that it was running great before i started... Just old and dried out rubber parts. I am petitioning anyone who can help me to offer up suggestions. I have had this carb on and off at least a half dozen times trying different things so far... Any thoughts?

 

[Xcusme]

Re: Rebuilt carb... Now won't start.

A Boss gasket seals the high speed jet drop tube FROM the fuel in the bowl. If missing, fuel will be drawn into the carb throat, up the drop tube, even at low rpm's. The fuel-air mixture will be way rich, rich enough to flood the motor. Missing the gasket pretty much negates the low speed needle valve as so much fuel is being sucked up into the throat, the slow speed idle ports have no effect. This assumes that the carb float is properly adjusted to maintain the proper amount of fuel in the bowl and NOT being set to allow too much fuel into the bowl.

 

[55'Fleetwin7.5]

Re: Rebuilt carb... Now won't start.

Thank you for your reply. I have re-installed the old cork float and needle. The float is "level" to the carb body when it holds the needle closed. I currently do not have any washer(s) around my high speed nozzle... None are shown in the illustrations in the manual for the 1957 lark 35hp- But I am hearing that they need to be there. I am getting a few small drops of fuel spitting from the area of the choke plate when i attempt to start... Getting a bit frustrated I must say. Any words of wisdom are very appreciated.

 

[Xcusme]

Re: Rebuilt carb... Now won't start.

Just for grins....what manual are we talking about here??

 

[55'Fleetwin7.5]

Re: Rebuilt carb... Now won't start.

The "original" Evinrude Exploded parts book from that year for that motor. I am using that as my guide. Should I be looking elsewhere? Please advise as I am sure you as an idividual and collectively have a ton more experience than I do. I appreciate your help.

 

[55'Fleetwin7.5]

Re: Rebuilt carb... Now won't start.

Would it be helpful if I scan a page and send it to you? If so, what address?
Thanks in advance for your continued help with this... I am getting a bit frustrated.

Thanks,

Tom

 

[Xcusme]

Re: Rebuilt carb... Now won't start.

Sure.....I did previously send you a PM.....

 

[jbjennings]

Re: Rebuilt carb... Now won't start.

Just a thought, mine always leaks a little dab of fuel when I choke it on my RD15 and bigtwin. I crank it with the pull start about 2 pulls on choke and then push the choke in and it cranks in about 2 more pulls cold. If your float needle isn't sealing, it will gush fuel out the throat nonstop.
Have you tried squirting a little fuel mix in the carb? How about taking the plugs out and squirting a little fuel in there? Have you checked spark since you put the newly cleaned carb. on? Sometimes getting it fired up and getting the cylinders "cleaned out" of old gas and getting ti warmed up a little helps in making your final adjustments on the carb. When you get the carb adjusted right, it should crank cold nice and easy. I'd put that donut gasket around the main jet as well. I believe in '53, they didn't use that donut washer but a lot of guys added one so it would crank easier, from what I have read. Yours has a different carb than mine, though.

 

[55'Fleetwin7.5]

Re: Rebuilt carb... Now won't start.

I have never done the squirt fuel mix thing before... I want to be clear on it before I burn down my garage. I take some of my normal 24:1 fuel and put it in a spray botlle...right? Then I spray it (stream or mist? one or two shots?) into the spark plug holes... - Or down the throat of the carb by the choke plate?... Is this the plan? I am game to try it. Just want to know because it will be a first for me. Thanks.

 

[Xcusme]

Re: Rebuilt carb... Now won't start.

Yup, the fuel squirt thing is as you describe. Place some 24:1 mix in squirt bottle, open choke (choke butterfly will be horizontal), squirt 1 or 2 squirts in the carb throat. On motors with a low speed carb blockage is should the motor to start and run until the fuel is consumed. Additional squirts with short pauses will keep motor running, albiet roughly, but it should continue to run.

From what you're describing tho, you have too much fuel.

 

[dade61782]

Re: Rebuilt carb... Now won't start.

doubt it is the needle being wrong. while you have it apart check the gasket to the main. I have found some of the sierra kit to have a gasket that is too thin and does not seal right. I have been making them from gas hose with a razor blade myself.

I just discovered this problem after i rebuilt my carb. rebuilt carb put it back on tried to start wouldnt start then I noticed fuel oil mixture coming out of exhaust. took out the plugs cycled the motor to blow out the excess fuel came in found this thread. took carb. back down put the old gasket back on the main jet and the new one on that buttoned it up. it fired up on the first try.