Hey I am having a slight pop when i up shift gears 1 thru 3 when you get to about 4k RPM. I have 18 SGS, TAB Zombies, and a full exhuast (no Cat). I thought this was just a pop from the slip ons being high output, and tried to tune it out with powervision quick tune like they recommend. It helped some but i dont want to go any higher on the fuel / spark.

I called Tab they said it may be the tune but i dont know of any other tune out there yet.

I called Dyno Jet and the guy said it sounds like an exhaust leak.. I guess i need to check but not sure how to identify that..

personally i dont see how it could be because its so intermittent, and only happens when shifting to second and third if you reach about 4k rpm before shifiting.. its not a decel issue because i can rev it way up and just engine brake it and no popping occurs... really stumped on this one.

 

M8 motors will do that with aftermarket pipes. If you had either, you would most likely notice reduced power and gas mileage. Look carefully at the exhaust for signs of discoloring or cracking near the manifold.

 

Fire the bike up, light a cigarette, or incense and watch the smoke. Into the manifold or away from exhaust. Sounds more like unspent fuel to me though.

 

So after playing with this for awhile. I have made sure all exhaust gaskets were torqued, I have called both TAB and Dyno jet. Tab says it sounds like a tune issue, Dyno jet said sounds like intake leak. So I put a new tune on it from TAB (their powervision tune) with the exact setup i have on mine they tuned for theirs. Right off the bat I liked the idling and some other things about their tune, So im keeping that one.

Second I rode the first half of my ride hard, doing everythign i could to get it to shift pop like it was, but nothing. I stopped ate, and rode back, now the bike was getting hot, and I know this because it seems to be when the engine gets HOT (hot enough to trigger the ETIS) and shut off rear cylinder. This and only then was I able to get it to consistently POP during shifts from first to 3rd again. Must get the RPMs near 4k and still a tiny pop.

This frustrates me because the pops are not nearly as bad as they were which im thinking may be tune related but then again they happen when the bike gets really hot. Im stumped and I know that harley is using the poly intake manifolds now and was wondering if they are expanding in the heat or if this is letting any air in.

Well, does that change anything for anyones opinion?

 

Got an update and a new problem. So I found an intake leak on the rear cylinder with the OEM manifold. I took it in and warranty covered labor, but i didnt like the plastic design so I decided to just upgrade to the new metal 55mm intake manifold. Long story short, dealer found, confirmed leak and installed the new manifold. I rode it back to the house the day of the fix and everything sounded and checked out ok, no pops etc.

Today I took it out for 100 miles, everything was great until the last 5 miles. I made a stop and during that acceleration up to speed the popping came back during shifting up to 4th gear as it did before. The good thing was the bike seemed to run better today, and NEVER got hot enough to activate the EITMs system, which seemed to come on all the time before todays ride.

So i got home and was stumped.. SO i did only thing i could think of, and checked the intake again. I sprayed and bam the seal is leaking AGAIN...

What could possibly be causing the seals to not hold like this?? This doesnt make sense at all... Is this a spec problem, maybe my engine specs are off and the seals/manifold isnt sitting right.. Or hopefully (well this would be best case scenario) the mech at HD didnt install it correctly or torque it to spec allowing it to leak again? I have done my homework on these and have found that its next to impossible to get a torque wrench reading on the lower bolts..

I dont want to be chasing this leak for ever..

 

There is a fine line for those intake seals, too loose and they leak, over torqued and they leak. Start by seeing if you can get them a quarter turn tighter and test again with your brake cleaner or whatever...