No gas to carb on C145

[MapleGuy 10]

Well, here's the latest challenge. With the forum's help, I got the old hydro oil changed out of my C145. I put everything together, hit the starter, and it wouldn't start. (It was running fine previously.) I had put a fresh fuel filter on it when I changed the hydro oil filter and I could see the fuel filter was still dry. No gas was getting to the carburetor. 

 

So I disconnected the fuel line at the tank, then cut the finger off a disposable glove and taped it over the end of the fuel line. When I hit the starter, I could see a slight bellows action in the glove finger. The fuel line had a couple of spots of wear, but it looked OK. To be sure it wasn't leaky, I disconnected the fuel line from the intake side of the fuel filter at the engine and taped the glove finger on the filter intake. Hit the start, same amount of bellows action. Disconnected the fuel filter altogether and attached the glove finger to the line into the fuel pump. Hit start, same amount of action. So I know the problem isn't the new filter. I blew into the hose and I could hear air whistling through the pump and into the carburetor. No apparent leaks or obstructions.

 

Any thoughts? Should there be more suction from the fuel pump that what I'm seeing? Do I have to prime it somehow?

 

Thanks for everyone's continued help!

 

 

 

 

 

 

 

 

[SPINJIM 1,981]

Many of the WHs with the fuel tank under the seat require some priming if they haven't been used for awhile, or if you've just changed the filter or lines.   Take the disconnected fuel line, and route it downhill from the fuel tank valve.  If you don't get any fuel by gravity feed, then the problem is inside the tank, either a clogged filter on the valve, or a defective valve.   I usually empty the tanks and rinse them with fresh gas whenever I do a rebuild.  It's amazing how much junk can collect there.  Usually have to also replace the valve.   

 

If the fuel flows with just gravity, then you might want to put an inline primer bulb to get it to flow uphill to the fuel filter and pump.   I bought marine type primer bulbs with 6mm connections on ebay, and they work great on three of my tractors.

   Good luck, Jim

[SylvanLakeWH 25,560]

 

Primer bulb on mine works like a charm...

[953 nut 55,230]

2 hours ago, MapleGuy said:

I disconnected the fuel line at the tank, then cut the finger off a disposable glove and taped it over the end of the fuel line. When I hit the starter, I could see a slight bellows action in the glove finger.

Good testing technique.                        The fuel pump has a diaphragm and two check valves, one for suction and one for discharge. If the suction check valve is not closing completely there will be no suction to pull fuel from the tank. If the discharge one is bad there will be no pressure exerted to lift fuel to the carburetor. In either case you will have pulsation rather than fuel movement. I have replaced many of my mechanical pumps with low pressure electric fuel pumps.

[Sparky-(Admin) 21,318]

The in-tank filter might be compromised. This is the one I swapped in a 312 last month. Fuel still flowed thru it believe it or not, but it had to be restricted. 

[Pullstart 62,884]

Lots of good ideas here!  I recall a mower of my friend’s that I had to blow air through the fuel line into the tank to unclog it.  It didn’t take much, but we were in the middle of nowhere and it was after closing time so I had to MacGuyver something.

[WHNJ701 4,165]

[AMC RULES 37,130]

Pull the air cleaner, add a good shot of carb cleaner in the carb, choke and hit the starter. Will typically run long enough to pull fuel through a dry system.

[AMC RULES 37,130]

If not, hit it again!

[MapleGuy 10]

Thanks for all the great suggestions! I have gone ahead and ordered an inline primer bulb, per SpinJim's suggestion. I already planned to replace the line, as well as the shut-off valve, for good measure. If that doesn't solve it, I guess a new fuel pump is in order. This forum is fantastic. Thanks for all the help.

[Pullstart 62,884]

if I haven’t yet @MapleGuy,  

 

Do you make syrup?  We have been for quite a few years on the hobby level, last season year was something like 15 gallons produced through the evaporator I built.