Bonneville America Forums Forums Technical Forums General Tech Backfires

Pulling on to the interstate today had a problem. Kicked it pretty good to get into traffic but as I was accelerating and hitting 5th gear it all of a sudden acted like someone hit the "governor" switch. No matter how much I twisted the throttle it wouldn't add any additional RPM. It also started backfiring over and over (Bam, Bam, Bam, etc...). I unscrewed the gas cap, no change. I reached down and checked the plug covers (both sides) no problems. Still had the "governor" and backfiring. After a few more minutes and just as I was getting ready to pull over to the side of the road it quits... everything back to normal. Didn't do it anymore on the way in and didn't do it on the way home this afternoon. Ideas?

had similiar problem on my 04 speedy turned out to be a loose connection with the plug wire in to the coil

Igniter…. Welcome to the club

Update: Changed the plugs (old ones looked great), removed and re-seated the plug wires into the coils. Ran great the last two weeks then this past weekend it started doing it again. Would do it for awhile (loss of rpm and multiple backfires) the quit and run fine. Well this morning running in to work, cruising normally in the HOV lane when all of a sudden BANNNNGGGGGG!!!! (massive single backfire) and the bike immediately dies. I swear to god I thought the motor exploded. Pulled over to the side of the road and checked the motor (it didn't explode). Guy riding behind me pulled up and says "what the f**k was THAT!" I said "backfire" he said "man, I thought your tire exploded". Anyway, it starts right back up and seems to have no issues. Shut it back down and get off to check and see where it has blown a small hole in the right side valve cover gasket and is leaking a small amount of oil out of it. Didn't see any other issues so I call the wife and tell her to pick me up at the dealer. Rode it all the way there (50 miles) and never had the problem again. I'm seriously perplexed... incidentially, when I got to the dealer they were too (this is the 3rd time i've had it there for them to check).

Holy crap Don. Keep us posted on what's going on. Think if that would have happened to me, I'd have to tell the girlfriend to meet me at the dealer with an extra pair of pants. Least you made it through safe; hopefully your ride is rolling again soon!

Will do Cale. I've got to get it back in good running order so we can do the fall leaves run through the mountains. I'm hoping some of the great mechanics we've got on here can shed some light on this problem (so I can share it with the dealer).

No kidding eh. If you want some company for your mountain run through let me know. If we can, Diana and I will head up; she loves this time of year.

sounds like a lectric problem. check the battery ground too. back in july you had this problem? you made no mention of backfires. when your sickle ratted out the polished 96 S&S cylinder on that chopper back in sep07 seems to me that is when weirdness set in. June 08 your throttle grip needed to be slid on the handlebar. you had the bike dying on you in July. for some reason you used seafoam in august. and now POWWWWWW! it could have taken that long for the neg ground cable to work loose to the point of your current pow. stealers working on sickles for weeks is scary.

your sickle is loosing spark then regaining spark. thus the pow. i would say check your float heights but fat is fat. it'll still run. and if it doesn't you'll see the gas puddle... intermittent loss of spark? grd cbl, coils, halls, puter.

Fuse box. did you pull all the fuses and grease em up? yes you did replug the coil connectors. were they tight? did ya grease those too?

check (meaning grease up) the connectors in the headlight bucket.

rework ALL the lectric connections all of em i say. right down to idle accessory plug. well maybe not that far.

don't loose sight though. start with the negative cable, then the solenoid connections.

Jim you may have hit the nail on the head. Mechanic at the dealer mentioned the same thing i.e. the troubles seemed to start after all the work to fix the bike after the accident. The last time I had it in they supposedly checked all the electrical connections and greased all of them. Also, they tested the ignitor and coils and said they checked out fine (i.e. they didn't know what was causing the stalling). Also, checked and re-balanced the carbs and checked the air vent hose. It was backfiring then too but not nearly as bad as this time around. Yes the coil wires had plenty of grease on them as well and they were on pretty solid. Since the problem seems very intermitent mechanic thought that it was probably a loose ground or connection somewhere (that they may have missed when doing the accident repairs). He said they were going to tear the entire bike apart (down to the frame if necessary) and put it back together from scratch. We'll see what happens. I'll keep everybody posted...

Follow-up... Interesting you mention my buddies chop that the BA hit in the accident. Since the accident he hasn't been able to keep a battery in his. Something keeps killing them (we've put 3 in it so far this year). Bottom line... accident damage isn't ever truly fixed.

UPDATE...

Got the bike back today. Problem was a faulty right side coil. Even with the bike out of warranty Triumph replaced it no questions asked. Also reset the air gap to comply with the tech bulletin (it was way out). Also, checked, re-greased and tightened all grounds and electrical connections and replaced the blown valve cover gasket. My instructions were to ride it like I stole it to be sure everything was shipshape. Triumph told the dealer if I had any additional problems that they would replace the other coil and the ignitor (as if still under full warranty). All in all (so far) running great and at no cost to me to repair/replace. My dealer (and Triumph) did me right... I'm pleased.

Cale, it's running better than it ever has. I am very happy with the results.