My bike ( 2010 Fat Boy Lo )was Dyno Tuned 2 weeks ago at HD with SE race tune. I have SE heavy breather and Rush slip on 1.75's
Rode it alot yesterday and today...
I am getting decel pop. Went to dealer and he said that will happen especially with the cross over pipe located just before the mufflers.
On my way home I was in 5th doing about 60. Let off the gas..and 'bang', backfire and popping.

This does not seem right to me...

 

Take it back and make them tune it right. If you wind it up to 5500 rpm in one gear and back off all the way down to 2000 rpm you may force a decel pop but otherwise it should not backfire just gurgle a bit when decelerating.

 

Ask to speak directly with Hiro, I was told he is actually a very good tuning technician. I assume you used LVHD.

 

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I went though the same thing 4ys ago...

On decell I'd get a pop,pop, BANG,,,BooM,,pop, pop BOOM..all the way down through the rpm;s..

It ain't the tune totally.... It can be,, but if they say they cant tune it out then......

Who ever put on the mufflers didn't get them sealed right,,,, Ur getting an Air leak.....

I Had the dealer retune mine 2 times to try to tune it out,,, no luck.. Then they said thats all they can do, ITS the pipes they said.....

I called Rush, in 60 second the rep told me to look in from the rear of the pipe to see if I could see light where the mufflers fit on the headers. Have someone hold a light at that joint while Ur looking in from of the pipes.
On, Ur 1 3/4's U may have to remove the baffles, I have the 2's so I didn't.

The pipes have 4 slots on each one where they clamp down on the headers, on mine I could see light at 3 of the slots on each muffler..


After Checking mine as the Rush Rep said too.
The wrench at the dealership didn't put the clamps correct, they were to far forward (actually 1/2 of both muffler clamps were clear off the front of the mufflers) causing the rear of the slots to raise which didn't allow to get a good seal,, causing the leakage which I could see easily by looking inside the mufflers.

Returned to the dealer for the 3rd time I showed them what was wrong and After they took off the pipes, actually had to straighten out the front of mufflers cause they were bent now from the improper install, then reinstall, put on New clamps, then re-dyno the 3rd time.....

GUess what----- no popping.... amazing what happens when a job is done right....

Also all the EXtra work was on their Dime..... they didn't like it but,,,,, Hey its Ur bike....

I will say that was the 1ST set of Rush pipes that they'd installed at that dealership(Remember I said it was 4ys ago). Still thats no excuse for a poor install of any pipe system.

I was pi$$ed at the pi$$ poor install,,, being a Machine Repairman all my life I don't like poor workmanship by a so called HD wrench.... and I told the wrench that. ( That wrench was fired and moved on later that yr) too many complaints on his work.. I don't want to cause anyone to be fired,,, just do Ur job correctly instead of blaming Ur mistakes on something else.

We all can Fu(k up but that wasn't even close to the quality of work I expected on my 1st visit (1k service) at the dealer...
Did it deter me,, No, but I'll say I've used 3 different dealer and 1 INDY to work on my bike....I haven't stayed true 100% to any one of them... except My own...

 

I did check the mufflers as you suggested OCT 1949 .. no leakage, but I will mention it to dealer..they are coming to get the bike tomorrow.

 

Yes, the tech was Eric