['08DenimSpecial]

I'm having some issues with backfiring on decel....problem is, it was running fine with rockerdan's pcIII advanced map for the pcIII and then all of a sudden I get some good decel backfiring and some nice flames shooting out of my rinehart. didn't change a thing. I thought maybe I got some bad gas somewhere, but I've since had about 10 tanks run through to no avail....any suggestions? I've checked all the bolts and clamps on the pipe...everything is tight still and I just changed the plugs as well.

...any help would be appreciated! :banghead:

 

[Dr Dave]

Is there water somewhere in this equation?

 

['08DenimSpecial]

Is there water somewhere in this equation?

huh? :stilpoke:

 

[Louis]

Best bet has to be a leak, tight clamps or not. Start it up and feel around for air before it gets too hot. I assume you checked the connection to head too...

Did this start when you changed the plugs?

Did you change the plugs yourself, are they the same brand and are they gapped correctly?

Airleak on the inlet side? I just changed the plugs too, and I tore than damn gasket under the airbox. I'm sure that can leak enough to cause real trouble though - you'd think not.

Does it run well otherwise? If so I'd try tuning it out taking the fuelling up and down a bit at low revs on a closed throttle.

 

[Louis]

huh? :stilpoke:

I assume he is asking if you could have got water in the connectors. However, yours, like mine, is late enough to have the PCIII under the seat where they don't normally get wet (unlike earlier bikes, where the thing was I think mounted in front of the airbox and got soaked).

 

['08DenimSpecial]

I did the hand test at the heads and clamp, and can't feel any leaks...I just changed the plugs and it's running exactly the same. I did the proper gapping on the plugs (.035mm) and they are the same plugs...

The bike is running strong...I tried 3 different maps that I had from the forums since the backfiring started and all 3 are backfiring the same. I was running it with a map for top on airbox and changed it to topless with rockerdans advanced map...still the same. :banghead:

 

['08DenimSpecial]

It is indeed mounted under the seat and I don't do alot of rain riding...I did get caught last w/e in the rain but it had the backfiring problem before that...

 

[Louis]

It is indeed mounted under the seat and I don't do alot of rain riding...I did get caught last w/e in the rain but it had the backfiring problem before that...

Favourites have to be an inlet or outlet leak or a duff PCIII. No 1 fave outlet (exhaust) leak, generally at the heads.

Unlikely but possible, valve lash overdue or head gasket? Running hot, using oil or coolant, white smoke in the exhaust?

Never tried this, but you could set the fuel at 0% throttle to massively minus on both pots (which will probably give you an off-idle flat spot), if the banging stops return it to normal on each pot in turn. If its one pot then it will be an air leak on that one. But I agree that's a bit of a faff, even if it works.

 

['08DenimSpecial]

I don't think its the pcIII because the bike is still running great except for the backfiring...if it was, wouldn't it be running like crap as well?

It's always ran hot and has always used oil since new...I haven't noticed any changes in th bike at all except the backfiring...I never thought of the valves...the bike has 30k on it, when are they usually due for adjustment?

 

[Louis]

I don't think its the pcIII because the bike is still running great except for the backfiring...if it was, wouldn't it be running like crap as well?

It's always ran hot and has always used oil since new...I haven't noticed any changes in th bike at all except the backfiring...I never thought of the valves...the bike has 30k on it, when are they usually due for adjustment?

Harley say 15K. Most people around here do 20K because it is such a PITA. 30K is valve time. Plus. Big time. Have you owned this bike from new?

 

['08DenimSpecial]

Well hell, I guess I'm due then! Yeah, I've owned the bike since new...I guess I'll have that checked...not an easy job? ....you mentioned a PITA

 

[Hal64hd]

Did you check your throttle position calibration on the PCIII?
I'm sure Louis can show you how to do it.

 

['08DenimSpecial]

Did you check your throttle position calibration on the PCIII?
I'm sure Louis can show you how to do it.

I don't know too much about the settings on the PCIII....so, no, I have not...

 

['08DenimSpecial]

I just reset the throttle positions...went for a quick ride before the rain hit. It seems to be a little better, but the backfiring is still there...I don't think its as much as before (when I let off the gas to shift, I would get a backfire between shifts, but now its not doing that...).

...any other settings I should be looking at on this thing?

 

[Hal64hd]

Did you check for exhaust leaks? The Flange nuts have a habit of working loose, and some members went to check them to find them gone.

 

['08DenimSpecial]

yeah, that was one of the first things I checked., they are nice and snug....I'm starting to lean towards a faulty PCIII. I went for a ride yesterday and the bike seems to be running the same with any of the maps that I have for the setup.

Is there any quick way to know if the PCIII is crap? quick setting I can do that would test the PCIII?

 

[BlueFlame]

yeah, that was one of the first things I checked., they are nice and snug....I'm starting to lean towards a faulty PCIII. I went for a ride yesterday and the bike seems to be running the same with any of the maps that I have for the setup.

Is there any quick way to know if the PCIII is crap? quick setting I can do that would test the PCIII?

Unplug it and see if it runs the same on the stock ecm without the pcIII piggy backed

 

['08DenimSpecial]

I did try that....backfiring is still there and the bike ran like crap...so I'm guessing the PCIII is working since it runs good when its hooked up (except for the backfiring!).

 

[vrodderD]

I'm not a PCIII expert, but I have had my Rinehart 2-1 for 2 years or more. I believe its the pipe, not the PCIII. The pipe is basically a straight through. you can get rid of "some" of the decel popping by adding fuel in the lower rpm ranges, but you'll never get rid of it completely, or at least I have never been able to. To test this theory, next time you're coming to a stop and engine braking, add a "hair" of throttle and you should notice the popping stops. Just my 2 cents for what its worth.

 

['08DenimSpecial]

yes, I did notice that...but the problem I'm having is I didn't have any decel backfiring at all...it just started all of a sudden....and definately no flames!!

I have another forum member tweaking my map to see if it will help....

thanks for all the helpful info people!