I hope someone here can shed some light on my situation....first off, I have a 2004 Sportster Roadster that I ride alongside my father, who has a custom (self-built) softail Harley that was built with all new parts and has less than 5000 miles on it.
Our problems began back in Oct. 06, we went for about a 100 mile ride and about 5 miles from home, my dad was leading and I noticed his bike started backfiring...he waved for me to ride up by him and he told me he couldnt give it any gas or it would go dead. We handicapped as close as we could to get home, but the bike was backfiring fiercely. Eventually we had to pull off the road..and since we were about 2 miles from the house now...I rode on home and got the tools and the truck. I also grabbed a spare battery he had in the garage just in case. While I was gone he ran the battery down trying to restart the bike, so we first installed the spare battery...he tried one last time to crank it, and it fired right up with the new battery, and made the last 2 miles home with no problem???? Once we got it home we were puzzled but figure the battery was the culprit and put the bikes up. The next day the bike would not crank at all and we started looking around and found the positive battery cable that goes from the battery to the starter was broken and we must of just luckily had it in the right place those last 2 miles. We replace the broken cable with a new OEM cable and some new plugs, and airfilter. We rode the bikes down and filled them up with gas and back home with no problems. The bikes both have been sitting up since mid-November.
OK, now the bike wont crank at all....we have replaced the plugs, its getting a spark...it seems to be getting gas, in fact if you turn it over and then pull the plugs its almost getting too much gas, the plug is still wet. We checked the condition of the gas and it seems to be fine. We have checked all the wires and fuses and links, all seems good. What puzzles me, is if its getting gas and a spark it should atleast hick-up or burp..its doing nothing, when you hold the plug up against the side of the motor it has a nice spark. I cant for the life of me figure it out, neither can my dad. I am a auto technician, so I am knowledgeable with such things and my dad is also a mechanic but somethings not adding up...we have gotta be missing something. Its a 1340 cc EVO with an SS carb, and electronic ignition..the engine was bought new from Harley in 2003. I am really wondering if all that backfiring it was doing did something to the SScarb, perhaps it backfired through the carb and screwed the jets up or something. Well if this might sound familiar to anyone, we'd really appreciate any advice. Thanks in advance.
Ron

 

Do a search or ask for info in the tech or do it yourself forum. There is a wealth of knowledge in those areas.

 

..water in fuel?

 

Thanks guys for responding...we have been told to try a new set of plugs, even though they are firing against the side of the engine block on the outside, I'm told they might not be firing inside the cylnder. We will give that a try and see what goes on...I'll keep you posted.
Ron

 

I don't know who build your Dad's bike may be a great builder... One thing we have seen here is a lot of electrical issues from poor builders. I have a friend that stays busy redoing shoddy work by some of these guys. Good Luck and hope you get to the root cause.

 

You say you have a spark when you hold the spark plug up to the jug, well, is it a blue spark, or is it yellow. If its yellow, could be wires, coil, or the coil is not getting the proper voltage.

 

OK...update. We went riding today, we simply put new plugs in it and it fired up and ran for about 40 miles, until it went dead going down the road. Just before it shut off the digital gauges started flashing and then finally shut off, *Battery was dead*? We jumped it off, and rode it half way back home, then we had to jump it off again to get it the rest of the way home...we have found that, it doesnt seem to be charging, and just running off the battery....??? Read my first post, I think that broke wire did something to the charging system some how...we are going to work on it more tomorrow, we didnt find anything "obvious" today. Any ideas on that one? Thanks
Ron