[tri650]

I just picked up an 02 955i yesterday and upon riding it home I got a very loud backfire on deceleration. It does not happen until I am in a lower gear and only happens once - but it is very loud. Almost like a gunshot. I picked the bike up in the city and was afraid I would start a gun fight when this thing went off with a crowd of people at a corner.

It is not the usual popping on deceleration, but a big, loud boom - and only once as you decelerate at lower speeds. Did not happen on highway as I was decelerating at high speeds.

I have searched the threads on this issue but no one else seems to have the single, loud boom problem. Any suggestions?

BTW - the bike is awesome. At 54 my body wasn't crazy about the riding position but it just reminded me I need to lose some weight and get back in shape. What a great bike. I will post some pics by this weekend.

 

[bradtx]

tri650, My '04 used to do that once in a while, generally if I had the throttle slightly cracked on decel. Hard as I tried I couldn't get it to happen on demand. My son was following once and said the flame was 2-3 feet long.

I don't know why it helped, but after changing the plugs (w/OEM) the cannon fire stopped.

Brad

 

[tri650]

Brad - good call. I just changed the plugs with the recommended stock plug and no more backfiring. Not even a gurgle anymore on decel. Thanks for the advice.

 

[Rayzor61]

Sounds like excessive build-up of unspent fuel/air mixture. Some bikes recycle this excess via the air box and polution control bull **** or thru an air induction system. Perhaps the plugs were'nt ingniting well enough or the gap was off. It's very easy to close the gap completely by accidentally droping the plug in the hole opposed to fitting it in carefully.

 

[doodledog]

Mine pops and Bangs on deceleration and if its a fault I dont care I love it, even better with the racing pipe tune and carbon can, just like a race bike, you can see the flashes in the dark too

 

[sparky955]

popping and sputtering

greetings everyone. i'm new to this forum and somewhat new to triumphs. i have a 2006 daytona 675 (scorched yellow of course) and as of a year ago, a beautiful black '07 thruxton. i had the dealer put on matt black predators as well as installing the proper jets and performing the necess airflow mods. well, the 675 rocks (esp at the track) but the thruxton has some fueling issues i hope someone may have some recommendations for.
in first gear, i can roll on the throttle aggressively to red line but in all the other gears, it sputters and actually decelerates. my mechanics have tried replacing the main jets with a variety of other sizes but the same symptoms occur. i'm guessing i need a proper jet kit, eh?! btw, the dealer went out of business about 6 months ago.
any recommendations would be appreciated. cheers!

 

[Kiwi Tiger]

A Sonic boom perhaps.

 

[RexxyPup]

Sonic Boom

Hi,

My ST used to do this. Same 2-3 ft flame! Was caused by the join between the endcan and the main pipe. There is a slot cut in the slip-on section of the endcan, and the slot wasn't always completely covered by the main pipe inside, allowing air to leak in, giving huge bangs on over-run. Cover the slot and it went away.

If new plugs don't do it for you, I'd look for an air leak at a join in the exhaust!

Rexx

 

[doodledog]

greetings everyone. i'm new to this forum and somewhat new to triumphs. i have a 2006 daytona 675 (scorched yellow of course) and as of a year ago, a beautiful black '07 thruxton. i had the dealer put on matt black predators as well as installing the proper jets and performing the necess airflow mods. well, the 675 rocks (esp at the track) but the thruxton has some fueling issues i hope someone may have some recommendations for.
in first gear, i can roll on the throttle aggressively to red line but in all the other gears, it sputters and actually decelerates. my mechanics have tried replacing the main jets with a variety of other sizes but the same symptoms occur. i'm guessing i need a proper jet kit, eh?! btw, the dealer went out of business about 6 months ago.
any recommendations would be appreciated. cheers!

Hi mate, if you go back to the main menu you will find bike specific forums for both the thruxton and the Daytona 675, great to have you here but as we are a Daytona 955 forum our knowledge of the thruxton is more than a bit limited, happy new year and welcome to ratnet, DD.