Victory Motorcycle Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
63 Posts
Discussion Starter #1
Long story short my bike got the V&H pipes, PCV, cams, timing wheel, Lloydz air filter and of course was dyno tuned by one of the big guys. After all these goodies I have a pop on Decel. I have read a technical tip at Lloydz webpage that there are many reasons for this to happen, and there is a list of things to do to determine the cause. The list is the following:

1. Cure the lean condition --- It was cured when it was dyno tuned
2. Cure all the exhaust leaks
3. Cure the intake leak
4. Cure the happy hand movements --- I do not think that I fall into this category
5. Cure the leaky injectors

I do not have a clue on how to check for the exhaust leaks, I can re-check if the torque values of the nuts at the header level are ok and also at the clamps on the pipes, but beside that I am clueless. If all are torqued ok, what is the best way to check for leaks on the gaskets or on the actual pipes? If by any reason I do not find the leak on the pipes, I think only dealership can do 3 and 5, and really I do not trust my dealership to do it (another story). How bad is for the engine to have this popping condition until in the near future I can visit one of the big guys?
 

·
Premium Member
Joined
·
9,684 Posts
Is it popping out the pipes or backfiring through the intake ? popping through the pipes is harmless in the short term , unless you are running super lean , I cant even fathom this issue if you just has one of the big guys working on your bike ... Guess nobody's perfect . If your backfiring through the intake , I wouldn't even start it again until it gets professional attention . This could be a timing issue do to improper cam chain alignment .
 

·
Registered
Joined
·
1,651 Posts
I've held a lit candle or the end of a long fireplace lighter near the exhaust port and looked to see if the flame flickered as if it was being blown on by a leak in the gasket.

G'day,

Vinish
 

·
Registered
Joined
·
63 Posts
Discussion Starter #4
Is it popping out the pipes or backfiring through the intake ? popping through the pipes is harmless in the short term , unless you are running super lean , I cant even fathom this issue if you just has one of the big guys working on your bike ... Guess nobody's perfect . If your backfiring through the intake , I wouldn't even start it again until it gets professional attention . This could be a timing issue do to improper cam chain alignment .
Thanks for the answer my felling on the popping it is on the pipes if I am hearing correctly, but really I do not know the difference in sound between the popping through the pipes and the backfiring through the intake, unless the backfiring sound is o the engine and the popping sound is on the exhaust, because mine sounds at the end of the pipe.
 

·
Premium Member
Joined
·
9,684 Posts
I've found popping on decel to be a lean condition and conversely upshift popping to be a symptom of an overly rich condition ... I just cant understand this issue after having a professional do the work ... If the popping is at the pipe that's the better alternative ... If its at the motor/intake , you don't want to be riding it that way . I would contact the shop that did the work ASAP and ask them to please advise ....
 

·
Registered
Joined
·
169 Posts
Light up a bowl, joint, bong, 1-hitter, what have you, and blow the smoke at the exhaust manifold where it meets the heads...while it's running of course, then you'll easily see if you have a leak there.

As far as the popping, finding out where it is popping is important. Sometimes decel popping is very hard to eliminate especially if you chop off the throttle or have very short pipes.
 

·
Registered
Joined
·
1,729 Posts
You stated you have "a pop on decal" do you always pop on decal. Are you running RPM's up then slamming the throttle shut?

Your new pipes V&H's are going to let you hear the popping that you couldn't hear with the stock cans on. Yes your bike was popping when it was stock.....It's just that you can hear it now.

Go thru all of your connections where you installed the Vance n Hines after running the bike and its warm then the next morning check them again when it is cold.

Call your tuner. He will ask you questions and lead you in the right direction. If he didn't install your exhaust then he is not really responsible for it. Did it do it on the DYNO ?
 

·
Premium Member
Joined
·
8,967 Posts
My train of thought is when you hotting up an engine and particuarly fitting a low restriction exhaust, that you gotta expect it to sound a bit like a hotrod on decel.
Fair enough not like a bloody machine gun but a little snap crackle and pop is character.
Friend on mine recently bought a 2012 Fatboy with dealer fitted Vance and Hines shotguns, and a screaming eagle fuel controller.
sounds wicked under power but back off and its a cacopheny of bangs not unlike a machine gun being fired.
My thoughts are it needs a PCV and a good tune to get it back to something thats livable with, at the moment its ridiculous.
But its not my bike, I cant see the point in buying an expensive bike and not setting up the tune.
Getting off topic here, what Im saying is free breathing pipes are gonna have some degree of 'character' on decel.
Thats the way I see it anyway.
 

·
Registered
Joined
·
1,007 Posts
On my last bike I found popping on deceleration directly linked to timing and the high octane number on the fuel if I ran premium. The lower the octane the cooler the cylinders and I believe it is recommended to run the Vics at the lowest octane you can without getting knock. Try dropping a class on your next fill-up and see if it makes a difference. If it doesn't, you've lost nothing and can start looking for the cracks.

 

·
Registered
Joined
·
35 Posts
Long story short my bike got the V&H pipes, PCV, cams, timing wheel, Lloydz air filter and of course was dyno tuned by one of the big guys. After all these goodies I have a pop on Decel. I have read a technical tip at Lloydz webpage that there are many reasons for this to happen, and there is a list of things to do to determine the cause. The list is the following:

1. Cure the lean condition --- It was cured when it was dyno tuned
2. Cure all the exhaust leaks
3. Cure the intake leak
4. Cure the happy hand movements --- I do not think that I fall into this category
5. Cure the leaky injectors

I do not have a clue on how to check for the exhaust leaks, I can re-check if the torque values of the nuts at the header level are ok and also at the clamps on the pipes, but beside that I am clueless. If all are torqued ok, what is the best way to check for leaks on the gaskets or on the actual pipes? If by any reason I do not find the leak on the pipes, I think only dealership can do 3 and 5, and really I do not trust my dealership to do it (another story). How bad is for the engine to have this popping condition until in the near future I can visit one of the big guys?
If you listened carefully to you exhaust sounds before V&H and other mods you would have heard the very same stock sounds under same conditions only very muted. I did and the same sound pattern is there with V&H Slip-ons, high flow K&N air filter only many times louder... not to worry but enjoy.
 

·
Super Moderator
Joined
·
5,063 Posts
My exhaust flange nuts were loose on my I torqued to spec but I have zero decel backfire even with drilled mufflers.
 

·
Moderator
Joined
·
13,242 Posts
same for me flange bolts were loose. Had to retighten them after three rides. All good now
 

·
Registered
Joined
·
63 Posts
Discussion Starter #13
Last weekend I went over all the bolts on the exhaust system (from the engine to the Slip-ons) and I found some of them that could be tighten a little bit, which I did but still have the pooping. On Sunday I went for a ride of almost 350 miles on back roads and the BOOM is still there, and happens mainly on deceleration between 3000 and 2700 RPM.
 

·
Premium Member
Joined
·
4,178 Posts
can you get a pic of your pcv map for both cylinders, 0% column to be specific
 

·
Super Moderator
Joined
·
6,378 Posts

·
Registered
Joined
·
57 Posts
On my last bike I found popping on deceleration directly linked to timing and the high octane number on the fuel if I ran premium. The lower the octane the cooler the cylinders and I believe it is recommended to run the Vics at the lowest octane you can without getting knock. Try dropping a class on your next fill-up and see if it makes a difference. If it doesn't, you've lost nothing and can start looking for the cracks.

What he said try a different octane to see if it helps I have read some stuff that this helps. It's simple and quick , it will help a mechanic narrow down your problem if this does not help .
 

·
Premium Member
Joined
·
4,178 Posts
1 - 20 of 21 Posts
Top