Stumped and gong crazy- carb rebuild, now engine won't stay running.

[kippstakes]

going nuts here. rebuilt my carbs about two weeks ago... that is all new gaskets, all fresh fuel line, and a fine de-filthing. finally put them back on and the engine (which ran well with the carbs absolutely gunked to custard) won't run for more than a few seconds. i checked the float bowls and noticed that one wasn't filling. took carb off, polished the needle and jet (again), made sure it wasn't sticking anymore, put the carb back on. double checked both bowls for fuel, good to go. also checked fuel pump and its adjoining lines- all working fine with great flow. just doesn't want to start. it will run for an instant with the choke on, then, with the choke off, will run for just a bit longer when cranked. a few times i was able to get it running for about a minute by manipulating the choke on/off- but grudgingly and barely alive. it seems to be getting fuel for an instant and then quits. again, all fuel lines are rock solid as is the bulb.
running out of ideas fast.
help please!
thank you

 

[pn]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

yeah from looking at your small pictures i can't tell much.. but if that's the color of rusty brown i'd say those are the gunkiest carbs i've ever seen, any kind of small grit that gets into your carbs can and will clog up your low speed mixture valves, i'm guessing you have a 50 hp. make sure you have an inline filter, take out your mixture screws and blow it out with carb cleaner/compressed air. that should do the trick. lightly seated and 1 1/2 out. if not you'll have to go through the carbs again.

 

[kippstakes]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

Sounds good, will try. Does this cleaning and 1 1/2 out apply to the fast and slow screws both, or just the slow?
thanks

 

[kippstakes]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

okay, cleaned the slow jets and adjusted the screws out. they were snugged up when i got to them. problem persists.
just doesn't make sense that the motor would run well with the foulest carbs i've ever seen, but when i polish and pamper them the thing won't run to save its life. incredible. guess it's time to take them off, again, for the fourth time. thing came close to the junk yard today. jk we'll get her runni

 

[Daviet]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

Can you post a model number, can't tell a lot by the photos.

 

[Otte]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

I just got done dealing with a VRO fuel/oil pump switch over to a pre-mix fuel pump so I will ask a question from that experience. You may have addressed this already when you speak of the bulb and fuel lines but I was not sure if that was just after priming the system before starting. Have you tried pumping the priming bulb just before the engine quits? Will the engine stay running if you pump the priming bulb at that point? If it will stay running then it may be a problem with the fuel pump or air intake impulse gasket and the carbs are simply starving for fuel.

Just a thought because your description is very similar to the way my '89 Evinrude 50 hp behaved before a new fuel pump went on today.

 

[TD_Maker]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

I would do a carb soak and start it all over again. You auto parts store will have the soak you are looking for. You know those little wire ties they use for a loaf of bread? I would explore every hole, jet, and orfice (with the wire) in each carb and blow them clean from there.

Some people are going to say NOT to soak the carbs in cleaner. Some are going to say NOT to use wire to clean out the holes and jets. But judging on the condition of the carbs in your pictures, I would give it a shot. I know this much, this method worked for me. The darn ethanol fuel plays havoic on the fuel system

 

[kippstakes]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

i'm very sorry, Daviet! normally this is the first thing i do. the engine is a 72, 50hp Evinrude elect shift.
so you were right when you said 50, good eye.
Otte, I will try pumping the bulb before it quits. fuel pump seemed to work fine before- i imagine it wouldn't have ran otherwise- but those things take a lot of jostling when working on carbs. who knows? thanks.
TD, it looks like i'll be ripping the carb off again, so i'll do some probing and let fly with the carb cleaner.. perhaps even a soak, sounds like a good idea.
thanks, guys!

 

[Otte]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

No problem Kip. All the best with your work and I hope you find the answer(s) soon.

 

[TD_Maker]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

Kipp,
Considering the condition of your Carbs, have you actually looked INSIDE of your fuel pump? I will bet the screen is plugged as well. For the money (less than $20 Bucks) I would buy a rebuild kit and rebuild that puppy to be sure. Keep plugging away, you will get it.

 

[Toddboat]

Re: Stumped and gong crazy- carb rebuild, now engine won't stay running.

Just had a similar problem. Thought I had the carbs immaculate but no luck. Then I soaked the carbs for 2 days after removing all plastic and rubber parts. It cleaned out pinhole sized openings that I never knew existed. I was surprised by how much I had missed the first time I tried to clean them. Reassembled after the carb soak and the motor runs better than it's ever run since I've owned it.