DR650 aftermarket exhaust pops on decel?

[888]

I just took a dr650 with an FMF slip on for a test ride and noticed that it really pops on the decel, I always thought this meant lean jetting...dealer reckons it has the full dyno kit and popping on decel is "normal"....hmmmm. Anybody have an opinion on the dealer's comments?

[tri boy]

Possibly sucking a bit of air through the header-muffler packing.
The idle circuit may still be a bit out also. (just cos a salesman says something, it normally isn't very accurate. ie, they are all full of shit).

I'll just add that valve clearances, and possibly worn valve/seat on the exhaust side can also cause this.

[JATZ]

I just took a dr650 with an FMF slip on for a test ride and noticed that it really pops on the decel, I always thought this meant lean jetting...dealer reckons it has the full dyno kit and popping on decel is "normal"....hmmmm. Anybody have an opinion on the dealer's comments?

My 350 "pops on decel" and I know it's running a weee bit rich,has a super trapp type muffler thingy hanging off the back,
so..... who knows ? :shrugs:

[Eddieb]

My stock bike with a few holes drilled in the end of the factory muffler pops on decel from higher revs quite a lot, I've read a few references to it on Advrider.com also. I know my bike is running a little lean.

[gav24]

I just took a dr650 with an FMF slip on for a test ride and noticed that it really pops on the decel, I always thought this meant lean jetting...dealer reckons it has the full dyno kit and popping on decel is "normal"....hmmmm. Anybody have an opinion on the dealer's comments?

Yep, Normal.

Unless anyone else knows how to stop it...?

Mine has had a Pro circuit pipe, dynojet, open airbox and performance filter from just about new. I have played about with the jetting, idle and airscrew, to get it as good as I can, or should I say as quiet as I can. I run the pipe with the spark arrestor screen in, as that muffles it bit, and changing the packing every 5 - 6,000kms helps. The bangs can be a bit annoying when you blat and brake heavily through town, but can be reduced by either turning up the tick over, or as I do, blip the throttle slightly when braking. Bit of a pain at times though. I will double check the seal at the link between the end section of the pipe and the header though...
I think the change to a "proper" carb, FCR etc fixes it - but I could be wrong

Usually I just let it pop pop pop! and enjoy it

At least it doesnt spit flames like my GSXR600 race bike used too, now that was cool, in a sort of "street hawk", "knight rider" kind of way

[NordieBoy]

Even the stock pipe pops on decel, you just can't hear it as easily.

The only way of getting rid of it is an FCR39MX flat slide carb with the coasting enrichener.

[gav24]

Knew that Nordie would be posting soon

I have fitted a "coating enrichener" to my bike - me!
Blip blip blip

- hey it works!

[warewolf]

Popping on the overrun is quite normal, but if you stick on a louder pipe then the popping is also going to be louder. Jet for mixture & throttle response, not noise.

It's like bluing header pipes - they should do that if the bike is not over-rich.

[bart]

Mine pops shitloads

Pretty normal I think. Like they said....louder the pipe, louder the pop

[Night Falcon]

personally I love a good POP on deceleration...the 990 with a set of wings cans was like a symphony....on occasion it was so sweet it brought a tear to my eye....yes its ok to cry at poping exhausts

[888]

Thanks for the comments, doesn't seem to be that major an issue so I'll be trading in the TTR250 for the DR650 next week. I have to say that the power on this DR is insane (compared to the TTR) and that was with MT21 Rallycross tires. I can't wait to continue the farkling on this bike. Hopefully it will be ready for next weekends MMMM ride.