Decel Popping

[dolt]

Got a set of Kuryakyn copper gaskets from RealHog. Installed yesterday and took a test ride. Still getting significant cracking and popping on deceleration. After the engine cooled, I retorqued to 115 inch-pounds per the manual. Ran engine for 5 minutes, let it cool down, retorqued again. Test ride after this shows no improvement.:newsmile042:

So far, I have gone though the stock type gasket, a stainless steel square section gasket, and a copper square section gasket. None of them seem to seal very well. I have to start believing that my technique is lacking.

Question : Is there a specific procedure or technique to getting the exhaust gaskets to seal? Should they be hot torqued? Retorque when cool? Whatever?

Thanks in advance,
Jake

You shouldn't have to be mucking around with gaskets; they all probably sealed properly. Sounds like tuning to me.

 

[PKSHED]

Mate if it's still popping on decel after all that I reckon it's in the air fuel ratio. You need to rich it up a bit. We over here in oz have been running with after market pipes/ muffs, a Big Joes fuel Shot. Big sucker or K&N filter and dial in the required info till presto.. no more pop.:s

 

[wildman9]

Rineharts will pop a little on decel, thats just the way they are. Unless its a loud crack or backfire, just ignore it.

 

[RetiredJake]

If you have the thundermax you should be able to get rid of nearly all the popping. Make sure you go into your basic setting and set the value of the decel fuel cut off to 1. 1 is on, and 0 is off. If it's still doing it when it's on pay attention to what rmps it's popping at and adjust the hi and low rpm's for the decel fuel cut off accordingly.

Checked, 'Decel Fuel Cutoff' was set at 1. Hi RPM was 2400, I know it cracks & pops from at least 3000. Changed hi to 3008, will check as soon as the roads dry. Can't be getting it all dirty after I just cleaned it up. :s

Thanks for the head up.

 

[cdn-bigfoot]

Rineharts will pop a little on decel, thats just the way they are. Unless its a loud crack or backfire, just ignore it.

I've had the same problems keeping my Cobra pipes sealed well at the gaskets. Nuts seem to keep coming loose. Mine gurgles more than pops on decel. I get one loud crack under heavy downshifts. Should I be concerned?

 

[RetiredJake]

Thanks WildSpirit97 :ap

Rode this morning to check the affect of raising the hi RPM limit on 'Decel Fuel Cutoff'. What a world of difference. I get an occasional pop now when backing off at greater than 3000 RPM. Other than that, it just burbles as it backs off. Sure wish I had this information before I spent several hours working on changing exhaust gaskets 3 times. :small3d023:

Thanks Again,
Jake

 

[wildspirit97]

Thanks WildSpirit97 :ap

Rode this morning to check the affect of raising the hi RPM limit on 'Decel Fuel Cutoff'. What a world of difference. I get an occasional pop now when backing off at greater than 3000 RPM. Other than that, it just burbles as it backs off. Sure wish I had this information before I spent several hours working on changing exhaust gaskets 3 times. :small3d023:

Thanks Again,
Jake

No Problem, Glad I could help. There's a lot more you can do with the ThunderMax than Just "tune" the bike. If you want to learn more about it you can open the PDF manual from the help menu on Smart Link software. There's a lot more info in there than what's in the 3 page booklet that comes with it.
I don't know how long ago you bought the ThunderMax or if you've ever updated the firmware but it might be a good Idea to make sure your running the latest firmware.

 

[eleft36]

Hi Hobbit,

I have the ThunderMax. There is complete control of the fuel maps, but a little scary. There is one map for every 256 RPM, from 0 through 7936, for each cylinder. They are based on fuel flow vs. throttle position. Then you have the ability to fine tune using the AFR maps. Also can adjust timing against RPM and throttle position. Not sure how much and where to adjust.

Link Up
Select ignition timing then Timing vs Engine speed
Add timing;
@768 to 1280 rpm set to 15*
@1536 rpm set to 17*
@1792 rpm set to 18*
@2048 rpm set to 19*
@2304 rpm set to 19*
leave the rest for now
Rerun auto IAC after the timing change

Save as, change the date on the end of the map ID

Unlink

Done


The retarded timing at idle causes popping on decel, it will idle much better adding timing.



Al

:USA

:CONNECTICUT

 

[wildspirit97]

Link Up
Select ignition timing then Timing vs Engine speed
Add timing;
@768 to 1280 rpm set to 15*
@1536 rpm set to 17*
@1792 rpm set to 18*
@2048 rpm set to 19*
@2304 rpm set to 19*
leave the rest for now
Rerun auto IAC after the timing change

Save as, change the date on the end of the map ID

Unlink

Done


The retarded timing at idle causes popping on decel, it will idle much better adding timing.



Al

:USA

:CONNECTICUT

I'm not doubting your word here, but I'm curious about where this info comes from. messing with the timing without a dyno makes me a little nervous.

 

[eleft36]

I'm not doubting your word here, but I'm curious about where this info comes from. messing with the timing without a dyno makes me a little nervous.

This is trial and error for sure.

I don't ride at wide open throttle or know anyone that does.

This was done a degree at a time, there is very little load at these rpm's (no pinging).

Factory timing is retarded compared to early-er pre-ECM models, I think for EPA compliance.

I also have made changes in AFR and Timing in higher RPM ranges, keep in mind I'm running a stock bike.

So far it runs quieter and smoother without pinging, mpg varies between 35 & 40 depending on the roads, back or highway.

I'm riding from idle to 3500 rpm not 5000, so why tune to where I don't ride.

Also my testing takes place in outside atmosphere and all road conditions.

My opinion on just changing fuel to air ratio doesn't make the most efficient tune, timing enters into the equation equally.

Al

:USA
:CONNECTICUT