help.. gas out carb, not to cylinder

[BillNH]

I rebuilt the carburetor on my 503, then put new crank seals in. It still won't start, I get fuel coming up around the choke plate, but the spark plug is bone dry, wuth good spark. Any ideas? It was running, I shut it off in the yard after a short run to move it out of my way, hasn't started since. I found a torn gasket in the carb, and rebuilt it. I checked the crankcase, and it wouldn't hold any pressure, so I put new crank seals in, now it holds 5lbs, for several minutes. This is driving me nuts, as my Arctic Cat is down for a new gas tank (warranty), and I can't ride anything LOL.

[Schoobytwo (Bruce)]

Not sure what you mean about fuel around the choke plate.

But, back to basics. If the plug is dry, then try putting a little raw fuel or carb cleaner right down the carb and see if you can get it to fire. If using carb cleaner, make sure it is the good kind of flammable cleaner, not the environmentally friendly stuff. Eventually, you should get fuel to the plug this way. If the plug is then wet and it's still not starting, then try new plugs.

At this point when you get it to fire, if it runs - great. If it starts and dies out, then my guess is there is something wrong inside the carb.

Hope that helps. Let us know what you find.

Bruce

[BillNH]

When I choke it, I get gas coming up around the choke plate, but the plug stays dry. I have great spark, on a dry plug, it never gets wet, as if no gas is getting into the cylinder, just spitting back around the choke plate.

[BillNH]

Well, I think I found the problem, the new cork gasket around the fuel inlet cover is leaking. I found this when I put the fual line back on after resetting the timing. It blew bubbles on the side away from the hose connector. When I took it off, the gasket fell apart. Now I am getting a new gasket on then I will be sure this afternoon. I am going to try my hand at cutting a new gasket from gasket stock. Wish me luck.

[Schoobytwo (Bruce)]

On a number of occasions, I've found this plastic inlet cap to be a very tight fit into the carb housing. If it is a snug fit, the cap may not seat well on the gasket as you mention. To fix this, I grind a little plastic off the circumference of the cap so the cap has a loose fit in the housing. It then makes a much better seal on any gasket under it.

Bruce

[BillNH]

Well, I finally got a chance to pull the flywheel and check the crank seal. I must not have looked at the shaft when I put the seal in, it's rust pitted, right where the seal rides. I guess a motor, crank, or sleeve are in my future. At least I have all summer to solve this one.
I pulled the flywheel and stator plate, looked at the crank, while turning it by hand, and found rust at the seal. When I pulled the seal and cleaned the rust, the shaft was pitted underneath, I can feel it with my fingers. Now, I just have to figure out the next step.
There are a couple vintage sled salvage yards around the area, so I will be checking them for parts, first. Hopefully, I can find a good motor cheap, and keep this one for parts, as I have a new coil, and rebuilt carb on it.

[BillNH]

Well, fast forward, I did replace the crank seals and got the little beast to start, last year, with no snow remaining. This year, same issue, when cranking, gas is blown up out of the carb when choked, plug stays dry. I talked to a couple people locally, and they agreed that it might be a plugged muffler. The reason for that is, with plug removed, crank engine and gas is sucked right up from the tank. Replaced spark plug, no gas movement and choking causes gas to be blown up out of carb, as is compression is coming back through intake. I unhooked the muffler and started it with starting fluid, which had not worked before. hooked muffler back up, and back to same as before. Now I guess I'll be pulling the muffler, hope I can get it out without taking off a track.