Exhaust poping on deceleration...

[mr.z]

allthough it sounds quite cool, like a muffled rally car...

when the bikes really got warm when going down a (very big) hill tonight i could hear the exhaust poping, allot, throttle closed in a reasonably high gear, not very loud but you could hear it allright, if i twist the throttle right back and let go it will pop....

I'm pritty sure there is a small hole in my exhaust, iv'e got some repair pasted i'm going to try at some point, also i suspect my air filter needs changeing, is that another likely culprit?

I was wondering, what is exactly causeing it? assumeing its the hole in the exhaust?
____________________
>RidingSkills<->Tech Tips<->MyBikes<

[alains]

which bike ?
____________________
the worst day fishing is better than the best day working

[Ste]

Have you got a race can fitted?

[stinkwheel]

Far as I know it is caused by small amounts unburned fuel in the exhaust system getting mixed with just the right amount of air to make it explode. Under normal circumstances it just burns-up in the hot exhaust, the hole gives extra air to make the mix explosive....of course I could be making that up, I have no definitive proof, just seems to make sense.

I'd check the tightness of the exhaust manifold studs too.

I suppose a choked air filter could cause it to run rich which would exascerbate the problem but I think there is probably a leak in the exhaust ststem too.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Scooby]

It's just the over-run. Don't worry about it.
____________________
A big enough hammer fixes anything!

[stinkwheel]

You should get someone to follow you in the dark, you will probably find that each pop is accompanied by a fairly reasonable sized jet of flame coming out of the exhaust .

If it is on your maggot I would get it seen to, I would worry about what it might do to the exhaust valves if it is happening a lot over a long period
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[mr.z]

Ahhhhhhh that makes sense .. actually just found this https://ourworld.cs.com/moonmist115/popping.html

My next question was the exhaust valve thing, i remember reading extreme backfireing action can damage them, never mind, it sounds really cool and lowering emissions! what more could you want

I'll get onto it i think, being my only transport i dont want any unexpected supprises, i'm hopeing it just this 'ole, been an eventfull few weeks with the old dear, as long as i dont have to have the forks in bits all over my shed any time soon its not going to be as bad...

[Kickstart]

Hi

As above, normally due to a leak in the exhaust system.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Finglonga]

[mr.z]

ah excelent, yep i know a guy who used to weld main gas lines for a liveing, he is rather good... hopefully he still has some gear...

Thanks for the help all
____________________
>RidingSkills<->Tech Tips<->MyBikes<