Was out in +9*c temps this weekend and this machine started dying. Near as I could tell it was vapor lock or ???. Took and removed all hood vents to let it breath better, but no change, and happend too often IMO to be vapor lock. If we ran it on partial choke is was OK for a bit, then full choke, and then it wouldn't even idle on full choke. ???
So now I'm thinkin' fuel pump. I haven't ever heard of any horror storys of the fuel pumps on these, but I am sure that the doo die occasionally eh? I actually first thought that the pulse line musta came off - but it was 100% fine. So I ran the tank line directly intot he T splitter at the carb and topped off the tank to make as much fuel press as possible. It would now run, but it still liked a partial choke. So we turned around and headed back fer the truck.
Partial choke yielded me aboot 5000 rpm is all and full choke would git me to 6000, but if I burped the throttle higher it would die instantly! Seemed to die too quickly to be a fuel delivery issue, but it musta been? It was like a truck with a bad accelerator pump on a cold morning eh? Still - it musta simply been running THAT close to the edge I guess....
We stopped for a second as the boy got hung going around some deadfall - or I thought he was anyhow... From that point on it didn't need the choke anymore at any throttle position, and if I did burp the choke it would stumble for beeing fat! I continued on for a bit and it stayed fine. ???
So now - to try to trouble shoot this I hooked the fuel pump back up! Ran fine! Turned the sleds BACK around and rode another 60+ miles intot he bush w/o a hickup.
Blew a piston on the other sled on the way back out the next day and towed it out in +9 to +12 temps in sticky snow and it never afford one bit of issues!
Motor was completely gone through only 50 miles before this ride, so everything had been apart recently, but no issues before or since. (Other than a broken throttle cable a few weeks ago
)
It just seems that there was something plugging it either in the supply line from the tank or at the Y tube at the carbs. But what?
Whatever it was - it seemed to be starving BOTH carbs, not just one.
I am sure that the fuel pump is fine as we ran the tank completely dry git'n back to the truck and we had just a splash of gas in the 5'er on the back - and it sucked it up and got us the last cpl clicks to the truck.
Or could this somehow be tied to the DPM?
I had the airbox off while feeding directly to the carbs. (Doo to reroute of the fuel line.)
Anyone ever have similar issues or any knowledgeable answers to this?
So now I'm thinkin' fuel pump. I haven't ever heard of any horror storys of the fuel pumps on these, but I am sure that the doo die occasionally eh? I actually first thought that the pulse line musta came off - but it was 100% fine. So I ran the tank line directly intot he T splitter at the carb and topped off the tank to make as much fuel press as possible. It would now run, but it still liked a partial choke. So we turned around and headed back fer the truck.
Partial choke yielded me aboot 5000 rpm is all and full choke would git me to 6000, but if I burped the throttle higher it would die instantly! Seemed to die too quickly to be a fuel delivery issue, but it musta been? It was like a truck with a bad accelerator pump on a cold morning eh? Still - it musta simply been running THAT close to the edge I guess....
We stopped for a second as the boy got hung going around some deadfall - or I thought he was anyhow... From that point on it didn't need the choke anymore at any throttle position, and if I did burp the choke it would stumble for beeing fat! I continued on for a bit and it stayed fine. ???
So now - to try to trouble shoot this I hooked the fuel pump back up! Ran fine! Turned the sleds BACK around and rode another 60+ miles intot he bush w/o a hickup.
Blew a piston on the other sled on the way back out the next day and towed it out in +9 to +12 temps in sticky snow and it never afford one bit of issues!
Motor was completely gone through only 50 miles before this ride, so everything had been apart recently, but no issues before or since. (Other than a broken throttle cable a few weeks ago
)It just seems that there was something plugging it either in the supply line from the tank or at the Y tube at the carbs. But what?
Whatever it was - it seemed to be starving BOTH carbs, not just one.I am sure that the fuel pump is fine as we ran the tank completely dry git'n back to the truck and we had just a splash of gas in the 5'er on the back - and it sucked it up and got us the last cpl clicks to the truck.
Or could this somehow be tied to the DPM?
I had the airbox off while feeding directly to the carbs. (Doo to reroute of the fuel line.)
Anyone ever have similar issues or any knowledgeable answers to this?
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