585 - are you getting popping on decel?

[BDWB]

I have a 585 cam and get popping on decel. I took it to a mechanic who has a good rep. He said that the popping is natural/cam working as it should- if he adjusts to get rid of the popping it will impact performance. I decided to live with the popping. Based upon reviewing all the threads it seems like many of you running the 585 are not getting the popping on decel. Just trying to validate if I am getting good advice on this? Perhaps I should get it on the Dyno and make some carb adjustments.

 

[KaptinAmerika]

Are you sure you don't have an exhaust leak

 

[highrisk]

I am running S&S .585 gear drive in my 95" Harley with true duels and thunder headers and have NO popping

 

[Germanbiker]

No popping in my 08 Pitbull. May be intake or exhaust leak. Check with brake cleaner on intake.
Jochen

 

[Sven]

Here's the deal. You have unspent fuel in the pipe. You lift, this lets fresh air back up the high flow kind of pipe (increases the sound un-muffled), meaning. This fresh air now reignites the unspent in the pipe. You more or less hear the pop of cold meeting hot air = Thunder clap.

Can you eliminate it? In your case, mufflers can is one. You could get some of it out, but at the sacrifice at the other end? You are more at a compromise, because you are going to take from one to band-aid fix the other.

If it was fuel injected, could you eliminate the pop? Yes. Depends on the ECU, which way to tune, what fuel or what ignition map to use?

 

[BDWB]

Thanks guys - didn't think to check the exhaust - if the exhaust is the issue wouldn't it happen at all times vs just decel?- Sven thanks - you are on the same page as the mechanic who looked at the bike.

 

[boomer4444]

i have noticed popping on my bike gets worse depending on the grade of gas i run,, 93 octane with no ethanol and hasnt popped since ,

 

[DR BULLDOG]

I am running a 107 -585 cam 5" Lake Pipe with Baffle I made pops very rearly -- Jetting and exhaust I had a set of those Big Radius on a 06 fuel injected bike they poped more than the set up I am running now good luck and Ride SAFE.

 

[BWG56]

I just installed a 585 and had the same thing until I rejetted the carb. inter.32 and main jet 78 and the popping on decel is completely gone.
Do a search on rejetting carb.

 

[mcgroom]

You should hear my 107 with a .600 in it.

Like I think Sven was saying, unspent gas. If you try to tune it out, bike won't be running the way it should.
Lots of discdiscussions on here about it.

 

[Sven]

Thanks guys - didn't think to check the exhaust - if the exhaust is the issue wouldn't it happen at all times vs just decel?- Sven thanks - you are on the same page as the mechanic who looked at the bike.

YW. Yeah, say it was the exhaust? You'd have the air leak in a spit/suck situation like you said. It would have to make a hissing noise on accel as it would on decel. It's a faster fresh air entering at the exhaust valve side, rather than down the tube being at the end of the pipe, correct?

Yes, I'm assuming the mechanic cleared any exhaust [leak] pop, and now generally explained the basics: 'for every action,' cold meets warm air and bang is the result. Because basically, aren't we talking hot and cold down a pipe and both meet about 8 to 9" in from the tip? I could see there was more heat right at that [blue] area. Just by the color of the raw [straight] pipe, before it was chromed later down the road. Well, that's where I assume the cold and heat meet, and that sure is close to an outer pop than a pop way up the pipe near the exhaust valve, right?

 

[Trainguy]

I just installed a 585 and had the same thing until I rejetted the carb. inter.32 and main jet 78 and the popping on decel is completely gone.
Do a search on rejetting carb.

X2. It's right in there i'm at 33/76.:2thumbs:

 

[Bobby Schulz]

Need to check for leaks and may need to go up a little on the jetting.

 

[oldmutt]

I had an on again off again pop on decel also. I went to 33 - 78 on the jetting and replaced the lock washers on the exhaust flanges. I would tighten the flange bolts and after a while they would back out and the decel pop would start again. So far so good.