Misfiring

[2003BDChopper]

My 2003 Chopper started this a month ago. It made a few coughs, and that was it. It was like someone removed the ground to the battery for a split second and straight back on. It almost threw me over the handlebars the first time cruising in relax mode :/

Then it started happening more and more. And last week i got stranded. Tank was emty. Got some fuel, i had a "funnel"? with me, but nothing to wipe it down with. And it wasent 100% clean. But i had to get the bike started, and it wasent THAT dirty . . After firing up the bike, it immediately started coughing again, misfiring with a little bang out the exhaust every 2 second or so. I was sure i had got some shit carb from the funnel. So i removed it, took it apart and cleaned it.

That didnt help. I checked sparkplugs, sparkplug wires and coil. The coil had about half the values it should have. So i got plugs, wires and coil to be sure. Put those on today, and..... No change ofcourse

You all thinking EHC.. ?? Any other thoughts?

 

[pknowles]

Strainer in the fuel tank/??

 

[2003BDChopper]

Is that located by the fuel on / off switch/ handle? Or inside rather?

 

[BWG56]

Yes, drain the tank and remove the petcock, the screen is attached to it.

 

[2003BDChopper]

Thanks.. Will try that first thing tomorrow

 

[HMAN]

Check both rubber caps on the carb. They can weather and cracks are hard to see. You can get silicon replacements at most auto parts stores.

 

[awg]

Well hope its NOT your EHC but when mine went bad it would just shut off at any time. It would start back up though. And once when I was crusing it just backfired out of no where. Kept running though. So you never know.

 

[Fitzy]

Same thing happened to me it was the liner in the tank coming a drift, removed the tank and petcock rinsed with new fuel and cleaned filter attached to petcock havnt had a problem since (heaps of shit came out almost like flakes of thin plastic) it wraps its self around filter inside your tank connected to the petcock and restricts fuel flow hope this is your problem as it is an easy fix easier than EHC problems
Goodluck

 

[woodbutcher]

Fitzy, did you not re-line the tank? there are threads on here about doing the lining. helps cut down on the rust in the tank especially with the ethanol in today's fuel.

 

[Mr. Wright]

Check both rubber caps on the carb. They can weather and cracks are hard to see. You can get silicon replacements at most auto parts stores.

What Hman says here about the rubber caps. If their sucking any air it will make it pop like that. Been there done that.

 

[Fitzy]

Fitzy, did you not re-line the tank? there are threads on here about doing the lining. helps cut down on the rust in the tank especially with the ethanol in today's fuel.

Not yet I have read all the info you guys have posted I probably should is it really that important ? it is hard to get the same products in Australia as the Us im just a bit lazy I am a Heli pilot so I have access to avgas that's all I run bike loves it

 

[woodbutcher]

as for me, i think i would go ahead and re-line my tank if and when it ever needs it just for the protection against rust. and as far as the AvGas, there is an active thread now going where a member put AvGas in their tank and a very reputable builder (John Sach) recommended against running it. might want to look up the thread, something about giving the dog a drink of the good stuff.


here you go: http://www.bigdogbiker.com/threads/fueling-up-with-da-good-stuff.73213/#post-677987

 

[Fitzy]

If I can find something here in Oz to reline the tank I will ill do some research now as for avgas I did read that thread it just runs so much nicer on avgas if I put pump fuel in it pings up top which is not good maybe I should find a happy medium and mix the two see if I can get the best of both world
Cheers

 

[grizfish]

Rode a HD Shovelhead for 20 years before updating my daily ride. Never had the original 3.5 gal. fatbob tanks lined. Still have those tanks and will use them agin on the next build. Never had any problems with rust in the tanks. Course, SoCal is a coastal desert, not much moisture in the air. Rode it across the Rockies a couple of times when it was a rigid frame, kick start only. Try going from sea level to over 11K ft. of elevation with a S&S B carb. and no spare jets. The stroker wheels and Andrews B grind cam made things worse.

 

[woodbutcher]

Rode a HD Shovelhead for 20 years before updating my daily ride. Never had the original 3.5 gal. fatbob tanks lined. Still have those tanks and will use them agin on the next build. Never had any problems with rust in the tanks. Course, SoCal is a coastal desert, not much moisture in the air. Rode it across the Rockies a couple of times when it was a rigid frame, kick start only. Try going from sea level to over 11K ft. of elevation with a S&S B carb. and no spare jets. The stroker wheels and Andrews B grind cam made things worse.

good info on the tank from somebody that's been there, thanks.

 

[2003BDChopper]

Took off the petcock today. The filter / strainer had a few small bits of dirt on it. wasent bad at all. The funny thing is, when i had drained the tank for fuel still mounted on the bike, i put my air gun in the tank from the top to try and get out the rest of the fuel. About 0.1 liter of what i think was water came out. Usually you can see the difference by the way it lands in a container. Fuel kind of flows out fast, and water is more lumpy.
I would have tried setting it on fire, but i was kinda in a hurry, and logic left me hangin :/

So could be water mixing with the fuel that made it behave the way it did ! Hopefully..... Got some heat under the tank for a few hours to vapirize the rest.

 

[FrankBDPS]

My experience with Big Dog tanks tells me they were lined to seal the pin holes in the welds. When I put stripper in the tanks it leaked out through several pinholes and ruined the paint job. Either way sooner or later you are going to have issues with them.

 

[2003BDChopper]

Yeah, i could see some green coating inside the tank. It had already started loosening just inside where the petcock is mounted, and where you fill the tank. I'll have to do some Research to see what i can get in Norway that will stripp it. Then i Guess seal it up somehow.

 

[2003BDChopper]

PS: Drying out the tank i sturred it abit to check for leftovers. Heh, i heard something. It was approx a 2 by 2 inch liner flake that had come off..

Can't get to it though. Anyone ever pulled out the housing for the gas cap?

Does it turn off ? And is it glued to the tank?

 

[woodbutcher]

PS: Drying out the tank i sturred it abit to check for leftovers. Heh, i heard something. It was approx a 2 by 2 inch liner flake that had come off..

Can't get to it though. Anyone ever pulled out the housing for the gas cap?

Does it turn off ? And is it glued to the tank?

at the factory, they used JBWeld to hold the bung in place. some heat will soften it up a bit and there is a tool for the removal of the bung. there is also a thread or 2 on here that show how to make your own tool.