McCormick W4 won't run

[DanB53]

I am trying to get my W4 going for the first time but it will only fire a few times then die. I cleaned the tank, sediment bowl, put a new screen on the sediment bowl, blew out the fuel line with compressed air, disassembled carb; put new jets, needle and seat, seals, and gaskets into it, put a new coil, distributer cap, rotor, plug wires, plugs, I've checked the point and spark plug gaps. The timing is a few degrees after TDC. I'm getting good blue spark and I'm getting fuel to the carb. It is a 6v system. If I put fuel down the cylinders it will run until it uses all of that fuel up then it will shoot fire out the exhaust and make a huge BANG. I can't figure out what else to check/do. I really need help figuring this one out.

 

[DJ54]

Seeing as you cleaned the fuel system from tank to carb., I'm assuming things may have been a tad cruddy. Where the fuel line attaches to the carb., did you remove the inlet screen fitting, and clean it also..?? A good spraying with a can of carb. cleaner usually cleans them right up. It's pretty fine screen, so be kinda' careful.

Can't remember if they have a plug in the bottom of the carb. If it does, you can remove, and see if you are getting fuel in the bowl. If not, either the inlet screen is plugged, or the float is stuck.

 

[DanB53]

Seeing as you cleaned the fuel system from tank to carb., I'm assuming things may have been a tad cruddy. Where the fuel line attaches to the carb., did you remove the inlet screen fitting, and clean it also..?? A good spraying with a can of carb. cleaner usually cleans them right up. It's pretty fine screen, so be kinda' careful.

Can't remember if they have a plug in the bottom of the carb. If it does, you can remove, and see if you are getting fuel in the bowl. If not, either the inlet screen is plugged, or the float is stuck.

I did clean that screen with carb cleaner, and when I pull that plug I get plenty of fuel out, I really doubt it's the float. I guess the inlet might have got plugged again, but it seems like I get pretty good flow when I take the plug out of the bottom.

 

[jimmysisson]

Sounds like no fuel. Are you certain of the correct float setting? New needle and seat shouldn't be sticking, but possible? Keep at it - you're on the right track.
Jim

 

[DanB53]

Sounds like no fuel. Are you certain of the correct float setting? New needle and seat shouldn't be sticking, but possible? Keep at it - you're on the right track.
Jim

I triple checked the float setting. And I was really careful putting it back in. It could be the needle and seat I guess. But it is doubtable. I'm still doing my best to trouble shoot. I'll keep you guys posted on my progress.

 

[DJ54]

If you have fuel in the bowl, next I'd check the metering nozzle, #17 on the exoloded view of the carb I posted. It will need to be removed, and check the cross drilled holes, to see if they are plugged.

 

[DanB53]

If you have fuel in the bowl, next I'd check the metering nozzle, #17 on the exoloded view of the carb I posted. It will need to be removed, and check the cross drilled holes, to see if they are plugged.

The metering nozzle is brand new. Before I put the carb on Monday I checked all of the passages and they were clear but i guess they might have become plugged. I'm wondering if the governer could be an issue? Does that effect anything to do with starting?

 

[MIKE R]

Here is the link to what I was saying to you earlier today.

Yesterday's Tractors :: View topic - w4 won't run

W4 won't run - Yesterday's Tractor Co.

 

[DJ54]

If it runs close to the throttle setting when you put gas in the cylinders, I wouldn't think so. It should activate fully though when that fuel is used up, and calls for more fuel, when the rpm's drop.

Is the choke plate fully closing? If I hand crank mine, I usually set the choke full, then within 3-4 turns, they will pop. Depending on the temps., either partial choke when cooler, or full off if hot, and 99% of the time, they run on the next crank. If electrical starting, full choke, and after 3-4 revolutions, they will fire up.

Either a fuel blockage, or a vacuum leak bad enough not to be able to pull the fuel up.

 

[DanB53]

Here is the link to what I was saying to you earlier today.

Yesterday's Tractors :: View topic - w4 won't run

W4 won't run - Yesterday's Tractor Co.

So he didn't tell me the whole truth when he said it ran good in the fall. I'm not too happy about that. But that still doesnt explain why it wont run now. Does anyone know the most common causes of loss of vacuum pressure and how to check?