Hesitation/Pop on hard decel from 3100-2850

[MarcV125]

Just a quick question if i could pick your brains..I have a hesitation/pop only on hard decel from higher rpm's, that hits from 3100-2750 then it clears up..If i slowly increase speed to 3.5k then let off it doesn't happen?.. I dont know if that makes sense or if that info insn't relevant but i figured i would throw that in there also..

I tried increasing fuel at 4% throttle by 5% at those two rpms and the pop became more prevalent, i tried decreasing by 5 % at 4% throttle and the pop was louder and hit harder.. What do you think i should try?...Everything else with the tune is excellent its just this little hiccup im trying to get out..
Thanks guys

edit: and what i mean by hard decel is NO THROTTLE, letting the motor engine brake





 

[strokerjlk]

What's your AFR set at in that area ?
Pinpoint the decel areas and increase fuel ( AFR table ) in that area.
Start at 13.2 and go from there .
If your AFR is set to 14.6 ( closed loop ) in the areas you are having trouble, you never will get rid of it just adding a few ve's.

[MarcV125]

stroker.. im set at 13.2 currently...  So your suggesting setting it lower 13.1 13.0 and going from there?.. in the 20 kpa column correct?.. right at the problem areas...

marc

[strokerjlk]

stroker.. im set at 13.2 currently...  So your suggesting setting it lower 13.1 13.0 and going from there?.. in the 20 kpa column correct?.. right at the problem areas...

marc

Yeah start at 13.0 might have to go 12.5 .
Start at 2500 and go to 3500 rpms

[rbabos]

Increase the timing in the effected rpms in the 20kpa area.
Ron

[strokerjlk]

Increase the timing in the effected rpms in the 20kpa area.
Ron

That will help some as well. 

[MarcV125]

Alright thanks for the help guys , i will test out on thursday and let you know..

marc

[joe_lyons]

You could also take fuel away and see how it does.

[MarcV125]

You could also take fuel away and see how it does.

alright guys i tried lowering a/f to 13.0 down to 12.5 and didnt see much of an improvement...The pop just hit harder in the exhaust and still hesitates?.. too rich ?.. should i try and go leaner instead?.

joe if you were to take away fuel where do you think i should try that? 4 percent throttle around the affected areas on both cylinders?..  and by how much
thanks
marc

[MarcV125]

also i was trying to be more attentive to when this really happens and ive noticed that if i try to make it happen going uphill, it virtually isnt there still a little hesitation but not nearly as bad..Going downhill and it gets much worse... so i would assume the more load the worse it gets, is it possible that i should try to increase the a/f in the 30 kpa column instead of the 20?

[joe_lyons]

Make sure no closed loop 30 and below kpa.  Up your timing at 20 kpa in the trouble spots.  Then take away fuel at the afr table as the ve numbers look "OK"

[strokerjlk]

also i was trying to be more attentive to when this really happens and ive noticed that if i try to make it happen going uphill, it virtually isnt there still a little hesitation but not nearly as bad..Going downhill and it gets much worse... so i would assume the more load the worse it gets, is it possible that i should try to increase the a/f in the 30 kpa column instead of the 20?

Your going to have to pin point the kpa and T/P it's happing at .
Could be more like 7 % T/P . Or it could be 2% . You need data . What T/P does your bike idle at?
Very seldom is it too much fuel .

[MarcV125]

Make sure no closed loop 30 and below kpa.  Up your timing at 20 kpa in the trouble spots.  Then take away fuel at the afr table as the ve numbers look "OK"

joe im at 13.2 everywhere for afr.. how much timing would you suggest to start with ? ..

also i was trying to be more attentive to when this really happens and ive noticed that if i try to make it happen going uphill, it virtually isnt there still a little hesitation but not nearly as bad..Going downhill and it gets much worse... so i would assume the more load the worse it gets, is it possible that i should try to increase the a/f in the 30 kpa column instead of the 20?

Your going to have to pin point the kpa and T/P it's happing at .
Could be more like 7 % T/P . Or it could be 2% . You need data . What T/P does your bike idle at?
Very seldom is it too much fuel .

stroker i idle at 3 percent t/p ..

thanks again guys

[MarcV125]

and again this only happens completely off the throttle..

[strokerjlk]

and again this only happens completely off the throttle..

You will have to do a data run to pinpoint the exact kpa location .

[joe_lyons]

What map do you idle at?  Bump your 20kpa timing by 10.  Set 20kpa afr to 14.2

[MarcV125]

and again this only happens completely off the throttle..

You will have to do a data run to pinpoint the exact kpa location .

I think this is next ...Will have to wait until another day

What map do you idle at?  Bump your 20kpa timing by 10.  Set 20kpa afr to 14.2

Joe she idles right at 11 11.5 map

Just tried what you recommended and that too did not help...still does the same thing

I appreciate the suggestions

[strokerjlk]

Can you attach your calibration?
If your truely idling at 11-12 kpa ? You have something going on there .
If you have a data log that would be good to see as well.

[MarcV125]

Can you attach your calibration?
If your truely idling at 11-12 kpa ? You have something going on there .
If you have a data log that would be good to see as well.

Stroker just to make sure i was looking at the correct setting, when i had it hooked up idling i was looking at Map load setting i believe it read, and when idling it was sweeping from low 11 to low 12 ..
sorry for my non tuning lingo, my calibration number reads 205UK005 -001 ... i do not see anything to attach, what do you need?..
my tuning settings are for a 120 w/ 6.23 injectors and if it helps my motor is a 117 with a 66hog

i ran out of time today to run a data log, i wont have time until next week most likely to run one..   

[joe_lyons]

Holy crap the cam settings are way off.  Pick a 110 calibration that has the 259e.  Bump the cubic inches up to 120 and change the injector size to match what you have now.

[MarcV125]

after speaking to joe tonight my idle was so low because it was reading in inches mercury not kpa's..so thats right in line, sorry for the confusion, im going to check for intake/exhaust leaks over the weekend and go from there..Again guys i appreciate your time

[7hogs]

I have reduced my decel cut to 0.00, idle is 13.2 and 20 kpa is 13.2, cruise is set at 13.8 bike runs like I stole it. Just got back from a trip no head wind avg 42 mpg with a bad head wind 38 mpg