Hello all, first post. Please be gentle!
I'm trying to restore a friend's McCulloch 3500 chainsaw. It's mid 1990s so getting on a bit. But seems in reasonable condition... other than fuel supply. It starts up & runs fine if I put fuel straight into the top of the carb, but stops when that's used up. So it's not drawing fuel from the tank. I've replaced the fuel lines & filter, cleaned the carb out & replaced the gaskets, diaphragms & needle. I have two questions:
1. Does anyone know what the fuel supply line connections should be? I'm not 100% sure that the lines, as I found them, are correct (see below)
2. Notwithstanding above, any suggestions on how to resolve it?
Fuel Supply
When I first removed the cover, the fuel supply lines were as follows:
1. Line 1 from tank to carb (with fuel filter in tank). Carb is a Tillotson HU-57A and only has one fuel port.
2. Line 2 from tank, connected to an in-line brass ferrule, then onto a rectangular piece of laminated soft material that has a plastic connector in it that the line terminates on. The material sits between the carb and the cylinder block.
That's it. Lines 1 & 2 are not connected in any way. There's no purge/primer bulb present even though the saw has a hole for one. Given the carb only has one fuel port, I'm not sure how a bulb would connect even if there was one.
I'm guessing line 2 is a breather for the fuel tank, and the brass ferrule is a one way valve to stop fuel escaping. But that means there's no way to prime the carb on startup. Maybe that's right? But then, why would the saw have an aperture for a primer bulb?
Silly question as a bonus: assuming the brass ferrule is a one-way valve, I presume I can test it just by passing fuel in? Should pass one way and not the other?
Many thanks for any suggestions.
I'm trying to restore a friend's McCulloch 3500 chainsaw. It's mid 1990s so getting on a bit. But seems in reasonable condition... other than fuel supply. It starts up & runs fine if I put fuel straight into the top of the carb, but stops when that's used up. So it's not drawing fuel from the tank. I've replaced the fuel lines & filter, cleaned the carb out & replaced the gaskets, diaphragms & needle. I have two questions:
1. Does anyone know what the fuel supply line connections should be? I'm not 100% sure that the lines, as I found them, are correct (see below)
2. Notwithstanding above, any suggestions on how to resolve it?
Fuel Supply
When I first removed the cover, the fuel supply lines were as follows:
1. Line 1 from tank to carb (with fuel filter in tank). Carb is a Tillotson HU-57A and only has one fuel port.
2. Line 2 from tank, connected to an in-line brass ferrule, then onto a rectangular piece of laminated soft material that has a plastic connector in it that the line terminates on. The material sits between the carb and the cylinder block.
That's it. Lines 1 & 2 are not connected in any way. There's no purge/primer bulb present even though the saw has a hole for one. Given the carb only has one fuel port, I'm not sure how a bulb would connect even if there was one.
I'm guessing line 2 is a breather for the fuel tank, and the brass ferrule is a one way valve to stop fuel escaping. But that means there's no way to prime the carb on startup. Maybe that's right? But then, why would the saw have an aperture for a primer bulb?
Silly question as a bonus: assuming the brass ferrule is a one-way valve, I presume I can test it just by passing fuel in? Should pass one way and not the other?
Many thanks for any suggestions.