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Discussion Starter #1
My bike was running great until midsummer. Then my stator took a crap. With all the wonderful help from browsing on here I was able to change it with one from TPE and also installed a MOSFET R/R. It charges approx 14.5 volts at all rpms now and runs great when cold or lower rpms.
However, when the bike is thoroughly warmed up it will spit, sputter and pop at higher rpms especially when accelerating at full throttle. I have tried back blowing the carbs, turned the screws on the carbs out 3 turns and marbled it to see if it made any difference. I took it for a ride last night and when cold no popping, but when warmed up popping like crazy when coasting and still the problems at high rpms, above 6k. No voltage change when warmed up so I'm leaning towards a carb problem, but what? I can't detect a carb boot leak, i used propane and no change in idle speed. I used new crush gaskets for the exhaust, but dont think it could be that. Please help I getting frustrated. Thanks for any help.
 

FREEBIRDS MC CENTRAL NY
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how long did it sit and did ya drain the fuel outta the carb bowls?sounds like dirty carb syndrome to me馃槥

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Discussion Starter #3
It sat for about a month, i have run 3-4 tanks of fuel through it since getting it running. I had put Sea Foam in the first tank, maybe I need to try more of that. Yes I did drain the carb bowls when I back blew them. Thanks for the suggestion though
 

FREEBIRDS MC CENTRAL NY
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did you drain the bowls before it sat?

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Discussion Starter #6
OK, I filled the carb bowls with sea foam and left them sit for about 2 days. I drained the sea foam out, back blew them again and took it for a ride. Once the remaining sea foam burnt up it was running exactly the same. Sputtering and popping at full throttle above 6k rpms and excessive popping when coasting despite marbling and turning the air screws out 3 turns. Could this be a mild case of fuel starvation, when I got done I could hear the fuel tank whistling? Otherwise the bike runs great, accelerates good until higher rpms, cruises at highway speed easily and idles at 1100 rpms without a problem. Any help will be appreciated. Thanks
 

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POOGS....Phantom Out Of Gas Syndrome.

Check your fuel tank vent to ensure it is not clogged. The nipple under the tank cap hinge leads out to the rear of the tank(under the seat) and a hose will be attached that drops down to underneath the bike (open to atmosphere). Check that you can get air all the way through that passage and out the bottom ( of shoot some carb cleaner down that nipple and see if it drips out the hose).

A whistle in the tank cap usually means air is struggling to get air in the tank to replace the fuel volume as the fuel leaves the tank. If the vent line is clear, your cap is the issue.

I took apart the tank cap on mine a few years ago and removed the diaphragm. Never had the whistle or POOGS again.
 

I'm a rider
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There could still be voltage issues from resistance when the RR is hot. Check the plug at the RR to see if it is overly hot on any pins after the bike is warmed up. One of my Vulcans would backfire like a gunshot when the RR warmed up and it wasn't getting good spark. Dumped too much fuel to burn off with a weak spark and shot fire everywhere I went. I noticed I was getting a lot of resistance on the pins when they got hot and it caused a voltage drop. Using better connectors I was able to eliminate the issue and the gunfire. These bikes are heavily dependent on voltage compared to some bikes. It went from popping like crazy to smooth as butter. There are 6 pins on that RR and ANY of them could have a voltage drop. Always measure at each pin at the RR, the rest of the bike could be fine on voltage. No less than 6 times I have rebuilt the carbs for a running issue that turned out to be voltage related instead.
 

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Discussion Starter #9
Thanks for the info on voltage. I cleaned my gas cap and tore a chunk out of the red rubber piece (diaphragm), is it safe to run without it? I will have to check the R/R. I am no means an electrician, I used the kit came with the plugs for the R/R, I used 12 guage wire from the stator and then 8 guage to my battery. I'm pretty sure anyhow. I only crimped the connections as I didn't have a soldering iron, now that I have one I need to practice soldering before I redo the wiring. Looks like I still have some work to do checking all the voltages Thank you very much for this info.
 

I'm a rider
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You may see some seeping when riding as it sloshes, no issues with pressure as you can run the bike off a solo cup with a fuel hose stuck in the bottom.
 

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Discussion Starter #11
There could still be voltage issues from resistance when the RR is hot. Check the plug at the RR to see if it is overly hot on any pins after the bike is warmed up. One of my Vulcans would backfire like a gunshot when the RR warmed up and it wasn't getting good spark. Dumped too much fuel to burn off with a weak spark and shot fire everywhere I went. I noticed I was getting a lot of resistance on the pins when they got hot and it caused a voltage drop. Using better connectors I was able to eliminate the issue and the gunfire. These bikes are heavily dependent on voltage compared to some bikes. It went from popping like crazy to smooth as butter. There are 6 pins on that RR and ANY of them could have a voltage drop. Always measure at each pin at the RR, the rest of the bike could be fine on voltage. No less than 6 times I have rebuilt the carbs for a running issue that turned out to be voltage related instead.
This sounds like it might be my problem. The excessive popping started a few days before my stator quit. It looks like I have some testing and electrical connections to redo. Now I just need the time to go through everything. I made a mount for my R/R for under the left side cover, I think I will put it back there after I check everything. Thank you for this info.
 

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So I rebuilt the engine and now I'm was having this popping noise. Ran it a little bit. To the gas station and such. Now when I go to start it won't turn over then I get a shot out the exhaust. Could this be related to these issues.
 

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Let me add to my last post. Once the engine cooled it ran fine. Popping started at around 2500 rpm and would go away at around 1500 rpm. Got worse the higher I went in rpm.
 

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So I just played with the carb boots and the clamps holding them. Didn't get much better except when the engine was cold. Once it warms up it went back to the same.
 
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