first off when i started the bike this morning it was hesitant to start up and once it did it sounded almost flooded so i blew it off and let it idled for around 3 min at 1500rpm then i blew some revs and it started backfiring with flames shooting out the back. my buddys a mechanic and he said it sounded like it was mis firing. what could cause that. then secondly it cleared up and stopped that nonsense so i took it for a ride at a redlight i took off and started to give it gas the bike sounded like there was something covering the exaust and the bike was going no where it reminded me of when u drive a go cart at a track and its time to stop and they hit the button on the machine and it kills 90% if the power well thats exactly what happend then in a sudden second with the bike almost at full throtle the bike kicked in and took off like crazy and i almost lost it. any ideas on the problems i am looking at. the bike does have to go in for a tune up before the season. thanks for the input

-matt leo

 

Fuel injected or carbs? Make and model would also be helpful along with year.

 

Considering it's posted in the F3 section, i would imagine it's an f3, and, being an F3, it's got carbs. Anything up to an F4I is carbed.

As to answer your questions, i wish I could help. But, i'm sure someone on here can help. Sorry I couldn't

Tylor

 

LOL. Thanks for pointing out the obvious and making me look dumb. Althought in my defense maybe he posted and didnt realize where he was posting. lol. I need to pay more attention. LOL

 

I would have to say that maybe your bike is running rich (hense the back firing). Try cleaning your carbs. Replace the plugs. One or more may be fouled. Check your air filter too and replace it or clean it (which ever applies). If all else fails get it to a shop for that tune-up. Lastly, how fresh is the gas in the tank? ****ty gas can do lots of weird things.

 

Sounds like you have a fouled plug that will fire sometimes and not other times. When it blows "fire" or backfire like that, it happens when the plug stops firing and builds up the fuel in the exhaust and all of a sudden bam!!!!! Then sometimes the plug will come back like in your case and run fine until u got to the light, then it fouled out and was a dog.... then all of a sudden it fired and you were off. Put some plugs in it before you go any further. Don't rip your carbs off just yet [sm=smiley20.gif]

 

F.Y.I. I dont mean in the order that I typed in my last post. I Agree that starting with the plugs would be the best place to start.

 

check your air passage ways as well because if they become loose the suction can suck gasoline into your air passage ways so you get all gas and no air.. wierd right? but just take off your air hoses and make sure there isnt any gas in them

 

Wow. Never thought of that.

 

My F3 had a fouled plug when it was backfiring like that. Before that I didnt drain the gas out over the winter and had to run bad gas through it and it backfired like that also.

But ya, change your plugs and see if that works out for you but dont be crackin her off right after you start it. That will definately foul your plugs.

Daniel Thompson