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-   -   Back Firing Vs. Decel Pop (https://www.hdforums.com/forum/dyna-glide-models/1228434-back-firing-vs-decel-pop.html)

Solina_Steve 04-15-2018 07:00 PM

Back Firing Vs. Decel Pop
 
I have just installed a new Khrome Werks dragstyle exhaust (with baffles) on my bike, and a K&N high flow air filter. I have NOT installed a tuner but I am considering buy a power vision.

It was about -3degC today when I finished the install and fired the bike up. I didnt ride but I tested it in the garage. On decel at higher RPMs I seem to get a backfire every time. This included an orange flame shooting out of the pipe. I expected some decel pop but not back firing to that extend. Is this normal without a tune? Will a tune fix this, or do you suspect there is something else going on. Bike ran fine with the stock exhaust and air filter.

This is on a 2015 Wide Glide

Thanks,

Ghost_13 04-15-2018 07:38 PM


Originally Posted by Solina_Steve (Post 17277917)
Is this normal without a tune?

Yes - its running rich



Originally Posted by Solina_Steve (Post 17277917)
Will a tune fix this

A dyno tune will fix it..., any other tune..., including one from the moco - will band aid it

Please do it right

Ghost

rideon 04-15-2018 07:58 PM


Originally Posted by Solina_Steve (Post 17277917)
I have just installed a new Khrome Werks dragstyle exhaust (with baffles) on my bike, and a K&N high flow air filter. I have NOT installed a tuner but I am considering buy a power vision.

It was about -3degC today when I finished the install and fired the bike up. I didnt ride but I tested it in the garage. On decel at higher RPMs I seem to get a backfire every time. This included an orange flame shooting out of the pipe. I expected some decel pop but not back firing to that extend. Is this normal without a tune? Will a tune fix this, or do you suspect there is something else going on. Bike ran fine with the stock exhaust and air filter.

This is on a 2015 Wide Glide

Thanks,

Get yourself a power vision from fuel moto. Tell them your bike mods and they will send a pre loaded tune, and away you go.

dorri732 04-15-2018 08:01 PM


Originally Posted by Ghost_13 (Post 17278022)
Yes - its running rich


Ghost

Adding more air (via improved exhaust and intake flow) without adding more fuel will make it run lean, not rich.

Ghost_13 04-15-2018 08:22 PM


Originally Posted by Solina_Steve (Post 17277917)
On decel at higher RPMs I seem to get a backfire every time. This included an orange flame shooting out of the pipe.


Originally Posted by dorri732 (Post 17278176)
Adding more air (via improved exhaust and intake flow) without adding more fuel will make it run lean, not rich.

Think..., before posting next time

Ghost

2500hdon37s 04-15-2018 08:37 PM

Considering? You need to go ahead and get the Powervision and get it tuned for the intake and exhaust.

Also those short pipes aren't helping the cause with popping and flames since they're shorter and much less restricted than the factory pipes, any unburnt fuel in the exhaust gases will ignite when it hits oxygen a the end of the pipe since it hasnt had enough time to cool via a long exhaust tract. I had Vance & Hines short shits for a short period of time on my bike and even after being tuned, and occasionally during aggressive downshifts and engine braking or WOT runs and the fastest shifts I could make they would throw a flame other riders told me.

Solina_Steve 04-16-2018 05:52 AM


Originally Posted by 2500hdon37s (Post 17278323)
Considering? You need to go ahead and get the Powervision and get it tuned for the intake and exhaust.

Also those short pipes aren't helping the cause with popping and flames since they're shorter and much less restricted than the factory pipes, any unburnt fuel in the exhaust gases will ignite when it hits oxygen a the end of the pipe since it hasnt had enough time to cool via a long exhaust tract. I had Vance & Hines short shits for a short period of time on my bike and even after being tuned, and occasionally during aggressive downshifts and engine braking or WOT runs and the fastest shifts I could make they would throw a flame other riders told me.

Okay Thanks man I will go ahead and order the power vision. It sounds like that is the answer. I dont mind a little back firing here and there as long as its not hurting anything. I originally didnt want pipes this short, but I got a really good deal on a used set. We will see how it goes for this season.

dorri732 04-16-2018 07:06 AM


Originally Posted by Ghost_13 (Post 17278262)
Think..., before posting next time

Ghost

http://www.*****************/forums/...rich-lean.html

I did think. I still think it's too lean at idle.

edit: it's vtwinforum.com. I don't know why we can't post links to other forums. Regardless, popping on decel is almost always caused by a lean condition.

Solina_Steve 04-16-2018 07:42 AM


Originally Posted by dorri732 (Post 17279121)
http://www.*****************/forums/...rich-lean.html

I did think. I still think it's too lean at idle.

edit: it's vtwinforum.com. I don't know why we can't post links to other forums. Regardless, popping on decel is almost always caused by a lean condition.

Considering the new exhaust and high flow air filter is introducing more air, I would think the problem would be that its to lean as well. but then having a backfire and a flame doesnt make sense. But I dont know I`m no mechanic!

Graham UK 04-16-2018 08:13 AM


Originally Posted by dorri732 (Post 17279121)
http://www.*****************/forums/...rich-lean.html

I did think. I still think it's too lean at idle.

edit: it's vtwinforum.com. I don't know why we can't post links to other forums. Regardless, popping on decel is almost always caused by a lean condition.

...and here are the two opposing views on the same page from 2007: https://www.hdforums.com/forum/gener...ning-rich.html

Both views have their own logic and perhaps one day I'll know enough to figure out which is correct. My own bike has quite of lot of popping on deceleration too.


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