So I had a weird issue come up on my last ride that I haven't seen discussed here before. Started out the day fine. Conditions were 12-18" of fresh, wet snow with snow continuing to fall and about 30 degrees. I had changed my helix angle by 2 degrees on the finish rate the night before the trip. Team Tied clutch so not much disassembly to do this. Sled felt sluggish and I thought it was the steeper helix combined with the heavy snow loading it up too hard. Stopped at lunch to inspect and realized the belt was about to come apart. New belt improved the situation substantially. Right before this I tried to climb a short, steep wall from a dead stop and the sled just would not rev up to go up it. About 4000 rpm and would bog out. A few other times that morning it would bog trying to take off like it had a TSS problem, but TSS has been unhooked for some time.
Fast forward a couple hours to the late afternoon when we were getting low on fuel. Got into the bottom of a ravine with no way out the bottom. Sled starts acting up again, but beyond what it had done earlier that day. It decides it doesn't want to rev past 3000rpm. It would rev to that point and just want to die. Once in a while it would get up to 3500 (engagement on my sled when it starts to move), but still die. I thought maybe it was clutch/load related so I rolled the sled up on its side far enough to get the track out of the snow and I could get it to rev up and spin the track that way. Eventually I got it feathered through the 3-3500 problem spot and it took off and ran like it was supposed to all the way up and out of the chute.
Now here is where it gets really weird. Any time you stopped and let the sled come down to an idle you couldn't get going again. If I stood at the front of the boards and two guys lifted the rear of the sled to get the track spinning with the engine running 4500 they could drop the sled and I'd take off no problem. Would run like normal and pull RPM like it should as long as you didn't stop. Furthermore, we figured out the sled would not even start if the nose was pointed down hill. If it was pointed uphill a little bit it would start first pull and idle just fine, but still wouldn't take off under its own power. I have a clear trail tank and could see where the fuel was when this was all happening. If fuel was at the back of the tank it could start. If it was all in the front it would not. When I got back to the truck I had maybe 2-2.5" of fuel in the bottom of the tank. This is the first time I've run it this low in quite some time.
This has me thinking that maybe I have a fuel delivery problem with the smart valves in the tank. Anyone experience these type of symptoms that were fixed by changing them out? One other thing that was different recently was I had some race fuel mixed in the tank from some low-elevation running I did on the last trip. Up until recently it had only ever seen 91. Maybe that brand/formula of fuel reacted with the seals in the valves? I pulled the whole works out of the tank this morning and the hoses seems to be pretty hard. The valves were holding fuel in the lines and not leaking until I turned the assembly on it's side. One of the rear ones then released and let air in, and then all the fuel ran out the front valve. Seemed odd, but I don't know how these things are supposed to work exactly. I didn't touch the valves when any of this happened. just holding them by the lines and pump.
Other pertinent info on the sled:
-BDX hood, intake, headlight delete (old style)
-900 BMP 197hp full motor kit with PCV
-Oil injection delete
-Cat Tether
-Diamond S Ti quiet can
-2018 Primary clutch, MDS weights, Tied secondary, 2015 style Ti jackshaft (400 miles on this setup)
-TKI Belt Drive geared 2.52
-162 3" PC track
-This year it has had a new voltage regulator, stator, PCV, and reeds. First dealer that mis-diagnosed the stator problem said they had all the ignition harness connections apart, blew them out, and greased them.
-2300? miles on the engine, wire harness, and fuel system.
-Sled started as a 2014 pro-lite so it's had all of the engine mods since it was new.
Fast forward a couple hours to the late afternoon when we were getting low on fuel. Got into the bottom of a ravine with no way out the bottom. Sled starts acting up again, but beyond what it had done earlier that day. It decides it doesn't want to rev past 3000rpm. It would rev to that point and just want to die. Once in a while it would get up to 3500 (engagement on my sled when it starts to move), but still die. I thought maybe it was clutch/load related so I rolled the sled up on its side far enough to get the track out of the snow and I could get it to rev up and spin the track that way. Eventually I got it feathered through the 3-3500 problem spot and it took off and ran like it was supposed to all the way up and out of the chute.
Now here is where it gets really weird. Any time you stopped and let the sled come down to an idle you couldn't get going again. If I stood at the front of the boards and two guys lifted the rear of the sled to get the track spinning with the engine running 4500 they could drop the sled and I'd take off no problem. Would run like normal and pull RPM like it should as long as you didn't stop. Furthermore, we figured out the sled would not even start if the nose was pointed down hill. If it was pointed uphill a little bit it would start first pull and idle just fine, but still wouldn't take off under its own power. I have a clear trail tank and could see where the fuel was when this was all happening. If fuel was at the back of the tank it could start. If it was all in the front it would not. When I got back to the truck I had maybe 2-2.5" of fuel in the bottom of the tank. This is the first time I've run it this low in quite some time.
This has me thinking that maybe I have a fuel delivery problem with the smart valves in the tank. Anyone experience these type of symptoms that were fixed by changing them out? One other thing that was different recently was I had some race fuel mixed in the tank from some low-elevation running I did on the last trip. Up until recently it had only ever seen 91. Maybe that brand/formula of fuel reacted with the seals in the valves? I pulled the whole works out of the tank this morning and the hoses seems to be pretty hard. The valves were holding fuel in the lines and not leaking until I turned the assembly on it's side. One of the rear ones then released and let air in, and then all the fuel ran out the front valve. Seemed odd, but I don't know how these things are supposed to work exactly. I didn't touch the valves when any of this happened. just holding them by the lines and pump.
Other pertinent info on the sled:
-BDX hood, intake, headlight delete (old style)
-900 BMP 197hp full motor kit with PCV
-Oil injection delete
-Cat Tether
-Diamond S Ti quiet can
-2018 Primary clutch, MDS weights, Tied secondary, 2015 style Ti jackshaft (400 miles on this setup)
-TKI Belt Drive geared 2.52
-162 3" PC track
-This year it has had a new voltage regulator, stator, PCV, and reeds. First dealer that mis-diagnosed the stator problem said they had all the ignition harness connections apart, blew them out, and greased them.
-2300? miles on the engine, wire harness, and fuel system.
-Sled started as a 2014 pro-lite so it's had all of the engine mods since it was new.