popping / backfiring after installing Arrow full system on 05 S4R

[♣ McKraut ♣]

finally hit up the joints where the stock header pipes meet the arrow pipes yesterday... on the front cylinder i used the ultra red RTV gasket sealant, and the rear i tried a big thick bead of ultra black RTV sealant.  both are supposed to be good for high temps, but i'm still worried they will get "blown out" by the pressure of the exhaust.  would i be better off trying out the copper-based gasket sealant stuff?  that's what i planned on trying initially but autozone was out of it.  haven't taken it for a ride yet; it's supposed to cure for 24 hours...

anyone else have good exhaust sealant suggestions?

[Langanobob]

Just another thought - have you checked carefully for a leak on the intake side?  I think I remember a thread where someone had a similar problem and had a hard time finding the cause.  It turned out to be a vacuum leak somewhere on or near the TB's but I don't remember exactly where.   Does kind of seem like an intake leak would cause some idle issues though.

[♣ McKraut ♣]

probably not related to the intake side...had a very experienced Duc mechanic balance the throttle bodies just recently....what a difference that made across the board, and the idle is great too.

haven't been able to stress-test the header pipe sealant attempts (been rainy and crappy lately).  hopefully if things dry out today after work i can take it for a spin and see if they hold.  i have to say i'm not all that confident in them though, but who knows.  still open for other sealant suggestions as well.

[Simon]

Hi,

I am new here and I just got a used 2003 620ie fitted with high mount Leo Vince carbon cans and K&N filter and I also have this backfire problems. Ask the local dealer here and they say it is a stock ecu and nothing can be done.

1 question. What cause it to backfire, is it too lean or too rich or something else more complicated?

And I also have another problem don't know whether you guys have this too or not. (sorry to high-jack your tread a little bit). It seams like when I am in 1st or 2nd gear riding very slow behind traffic, stop and go can of ride, I always got a miss fire. If you guys have any idea or suggestion what I can try I would be very greatful.

Many thanks in advance.

[EEL]

finally hit up the joints where the stock header pipes meet the arrow pipes yesterday... on the front cylinder i used the ultra red RTV gasket sealant, and the rear i tried a big thick bead of ultra black RTV sealant.  both are supposed to be good for high temps, but i'm still worried they will get "blown out" by the pressure of the exhaust.  would i be better off trying out the copper-based gasket sealant stuff?  that's what i planned on trying initially but autozone was out of it.  haven't taken it for a ride yet; it's supposed to cure for 24 hours...

anyone else have good exhaust sealant suggestions?

Red wont work..I had this same issue with my arrows (when I still had them on my 05 S2R). I'm sorry to give you the bad news but even ultra copper didnt work it blew off as well. The heat from the heads is too high and the RTV will turn brown I cured that sucker for 3 days and the RTV only lasted for a few hours.

So, that said, being the purveyor of cheap fixes to common problems, here are 2 methods that might come in handy.

1) If the slip fit connection is loose you can tighten it but shimming the inside of the stock header pipe with a thin metal. Cheapest solution? Take a 12 ounce coke can and cut it up with metal shears (careful not to cut yourself). Wrap a strip around the stock flange and insert. If its still loose, cut out another and double it up. The sheet aluminum is heat resistant and very uniform in thickness.An added bonus is that it naturally curves just like your pipes. If you want you can use a bit of ultra copper rtv to set in into place and keep it from moving when you install. This is probably the easiest fix.

2) Nashua 322 aluminum foil tape - it has an adhesive which will smell a little for the first day as it burns off but it will seal. I prefer the above method more but if you have trouble getting the coke can piece to stay in place, this is your second option.

I'm going thru the same backfiring issues you are with my new boomtubes. Lots of fitment issues have caused me some big headaches. If the above dont work, please post and I'll give you another option. Its more "out there" (carbon fiber weave mixed w/ Copper RTV). The fitment issue on my boomtubes is bad enough that this is may be my only option. I'll know this weekend if it works. This fix is more costly (9 bucks).

[♣ McKraut ♣]

yeah, this is basically what i was thinking i would need to do if i wanted something that would last.  i used the ultra copper before and didn't really think it did a terrific job of sealing up...and blew out in a couple places, but i thought maybe i just hadn't done it properly.  i haven't ridden it yet or fired it up even, just to ensure that it at least gets plenty of time to cure.  i'll be taking it out saturday morning for a decent length ride, so i'll see how it's faring at the end of that.  kind of wish the full system would just come with one of those circular squishy steel slip-on gaskets that slips on the male end.

[EEL]

Dont judge it on one ride..It took a couple of days to completely blow out..you'll be back to where you were before after a weeks worth of riding..

[silentbob]

I had an 04 S4R with Arrows and had the same problem.  It is very common. 

The problem is the donut gaskets between the stubby headers and the Arrow system.  Your ECU didn't suddenly change the mixture, the gaskets just broke down over time from the pipes moving around.  The mounts on the Arrow system suck.

You will notice that after you remove the cans to change the rear tire that the popping will get worse.  I used two donut gaskets on each pipe and change them every second rear tire.

Don't waste your money tuning.  Buy 4 donut gaskets and the popping will stop.

[♣ McKraut ♣]

I had an 04 S4R with Arrows and had the same problem.  It is very common. 

The problem is the donut gaskets between the stubby headers and the Arrow system.  Your ECU didn't suddenly change the mixture, the gaskets just broke down over time from the pipes moving around.  The mounts on the Arrow system suck.

You will notice that after you remove the cans to change the rear tire that the popping will get worse.  I used two donut gaskets on each pipe and change them every second rear tire.

Don't waste your money tuning.  Buy 4 donut gaskets and the popping will stop.

donut gaskets from ducati, or from a third party vendor??  i'll have to double-check my box of stock pipes, but i don't remember having any donut gaskets when i took it off...

[silentbob]

donut gaskets from ducati, or from a third party vendor??  i'll have to double-check my box of stock pipes, but i don't remember having any donut gaskets when i took it off...

From Ducati.  They go between the stubby headers and the Arrow system.  They are a pregnant dog to install without destroying them.  They are probably still stuck in the udder.

[EEL]

bet you 10 bucks they're stuck in the expanded portion of your stock udder.  . Buy new ones.. they really do suck..

That being said, my arrows still leaked even after I installed the gaskets.

[♣ McKraut ♣]

glad i didn't take you up on that...i pulled the udder out of the closet yesterday and there were the steel gaskets.  i was in such a rush to get the beautiful arrow system installed that i didn't even look for them at the time.  at any rate, i'm going to try to get them re-installed tonight, and also try to use some teflon tape and ultra black RTV sealant as well, to really try to seal those two joints up.  i'm thinking if i put teflon tape around the male end...slide the gasket over that, and then put some ultra black RTV on the inside edget of the gasket, and slide on the female pipes over top of that, it should be a pretty tight seal, yeah?  and i would think the RTV wouldn't be able to "blow out" with those steel donut gaskets in place.  worth a try at least.

[silentbob]

Teflon tape will just melt.  Buy new donut gaskets and get two per pipe.  Forget the silicone.

[♣ McKraut ♣]

hmmm....i've heard from other sources that the teflon tape will hold up...as in, it may melt a bit and whatnot, but would hold it's ground and be a fairly "permanent" thing.  i'm thinking there's only one way to find out.

that said, i'll be picking up some new donut gaskets this weekend from AMS and will try the "double-up" method...one new and one used gasket on each pipe.

[EEL]

I'm tellin ya man..coke can shim w/ ultra copper rtv is the best way to go..