Hard Starting....

[Thompy_04]

Had a post on my 18 horsepower Johnson that really helped alot, but I have a new prob. I'm getting good spark to both cylinders, and the bulb will stay pressurized before the start. Once started after a million pulls, it won't stay running unless I pump the primer bulb. I suspect a fuel pump prob, and broke the thing down. Didn't look bad, and the diaphram didn't look bad either. Looked all all internal fuel lines on motor and no cracking or rotting and all connections are tight. Changed the ends of the tank to motor lines still same prob. Runs great when primer bulb is pumped but as soon as you let off of it it will die. Fully disassembled carb and cleaned it with new parts and adjusted float to specs. I would like to know where the vent on the fuel tank is, maybe thats the culprit. Stumped guys, any help?

 

[petrolhead]

Re: Hard Starting....

I'm not sure where the vent is on your tank either, I guess a small hole in the cap though, isn't that where they usually are?<br />Why not just crack open the cap a touch, enough to let some air in, that'll tell you straight away if it's a vent/breather problem.

 

[plasticfailure]

Re: Hard Starting....

just to make sure the pump is working, take the fuel line off after the pump and pull it over and see if gas runs out. you can also prime the bulb with the line off and see if gas runs out, maybe a clog?<br /><br />i was working on an older chrysler and we couldn't get it started and there was something wrong with the hookup to the engine and gas wasn't flowing through it, fixed that and it was fine.

 

[stairliftoheaven]

Re: Hard Starting....

is you fuel pump mounted on the side of the block or on a bracket?

 

[Thompy_04]

Re: Hard Starting....

To answer your question the fuel pump is a two line pump that works off crankcase pressure and mounted directly to the crankcase. I took the motor down to the marina today to see what was goin on with it. After countless times pulling and checking, pulling and checking I got it to start. I did notice a little fuel coming from the crankcase seal, but not like a spray or anything just enough to notice. Would this hinder the prob with the fuel pump? Put new plugs in today and it seemed to help a little. It will run without the primer bulb pump now but still seems like a fuel prob. I checked the fuel pump, and just a slight amount of fuel comes out the line. Should a large stream of fuel come out as I pull the rope? I took the carb apart and cleaned replaced all parts. When I did get the motor to run, it just won't plane. To me seems like a fuel restriction prob, so I sprayed some premix in the cylinders to no prevail. The cylinders have good compression, I'm just stumped!

 

[plasticfailure]

Re: Hard Starting....

so when you get it started it doesn't rev up?

 

[Thompy_04]

Re: Hard Starting....

Exactly, after about 20 or 30 mins I'll get her goin, then she won't rev and I have to keep the throttle up or it will die. I either have to get it in gear real fast so it I can bring it up to higher RPM's or just hope it doesn't die at idle. The kit I bought didn't have the new float for the carb, could this also be a prob. The old one looked ok, just kind of a cedar color not the typical cork looking. WOn't rev even close to the 4500 rpm its rater for. I don't have a tach, but I have ears, and my eyes tell me its not on plane.

 

[Thompy_04]

Re: Hard Starting....

Anyone have any idea? Reaalllllyyyy am stumped.... Been working on this thing for at least 3 weeks and can't get it goin. Really am wanting to get out to bass fish, and they're not gonna catch themselfs. Thanks guys.