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biknut
9th October 2009, 18:51
The purpose of this poll is to try to shed light on the benefit of single fire ignitions, and the relationship they have on the dreaded phenomena of carb farting.

We'll start with the assumption that the bike is in a reasonable state of tune, and maintenance.

biknut
9th October 2009, 19:00
Bike bike is single fire and it did fart once last year. I can't remember the last time it farted before that.

It hasn't farted one time so far this year, even though I've been doing a lot of jetting work on it.

SpartanDen
9th October 2009, 19:16
i marked at least once per month. I have minimal farts now after rejetting. Temperature has a lot to do with it as it is doing it more so now it's cooler than in the summer. Plus once it gets fully warmed, it hardly ever farts.

biknut
9th October 2009, 19:18
i marked at least once per month. I have minimal farts now after rejetting. Temperature has a lot to do with it as it is doing it more so now it's cooler than in the summer. Plus once it gets fully warmed, it hardly ever farts.

Is it correct to assume you're dual fire?

humpbackbob
9th October 2009, 19:24
Single fire, actually less than once a month but more than once a year....more like once a quarter. Last time was last week. Cold engine, had not ridden in a week and the temps here had dropped to 70ish after months of 100*. Not a concern.

jimmyess333
9th October 2009, 19:31
i marked at least once per month. I have minimal farts now after rejetting. Temperature has a lot to do with it as it is doing it more so now it's cooler than in the summer. Plus once it gets fully warmed, it hardly ever farts.

Same here, on a 2006 883.

SpartanDen
9th October 2009, 20:14
i have single fire.....

Jt1200r
9th October 2009, 20:40
mine did it twice today. damn it

bikerider
9th October 2009, 21:13
Since installing a Mikuni,N4 cams and single fire ign. my bike has never farted--I think it has a lot to do with the engine idle speed.My indy recomended about 1000-1100rpm to allow good lubrication (oil pressure).I have dropped the idle down to have a really cool lopey idle but then the system leans out when cracking the throttle and farts.

I kind of like having a really responsive throttle so my idle is a little high.

bigbluebowtie
10th October 2009, 00:34
Mine is finicky. It farts when it is cold, then never again when warm until I let off. I am set a little lean in the bottom though. That will change later. Just need to take the time to do it.

bustert
11th October 2009, 01:44
bikerider:
your mechanic has told you right!!!
on the gearotor pump, you must idle 1k because below that it loses effiency.
the old gear pumps could go to death idle and they would still put out a reasonable amount of oil.

toe
11th October 2009, 01:55
I've had both on my 2000, which may be a better measure as the only difference would be the ignition....

With the stock dual fire, it would carb fart about 1 out of 4 rides.

Then changing to a single fire (Crane HI4) with no other changes, the frequency went down to maybe once in every 10 rides.

Then with when the HI4 started acting up, I put the stock dual fire back in and the frequency doubled from the single fire (1 in 5 rides)

toe
11th October 2009, 01:56
Can you modify the poll so I can answer for the single fire and dual fire ignitions, since I've had both?

biknut
11th October 2009, 03:03
Can you modify the poll so I can answer for the single fire and dual fire ignitions, since I've had both?

I'm sorry toe, I don't think we can edit a poll after posting.

cantolina
11th October 2009, 05:25
I can edit the poll, but not change it to "multiple answers allowed"

Carb farts are a tuning symptom....not typically one dictated by time...

I kinda don't get the poll, myself... :dunno

You're trying to answer the recent question about single-fire vs. dual fire ignitions and how they relate to carb farts...but you qualify it by assuming a "reasonable" state of tune...

IMHO, in a "reasonable" state of tune, carb farts aren't an issue...with EITHER ignition... :dunno

When I DO get carb farts, it doesn't tell me to change the ignition...it tells me fall is here and I need to richen the idle mixture a tad... ;)

It is ALSO my opinion that it may be true that carb farts might be lessened by a single-fire ignition, but that simply hides the symptom of the lean condition...it doesn't fix the tuning...

toe
11th October 2009, 05:35
When I've had the carb farts, 95% of the time it's when the choke's in, but not fully warmed up; which would point to leaness.

Once warmed up, I've never had a carb fart with single fire.

With dual-fire there would be an occasion fart when fully warmed up........

biknut
29th October 2009, 05:14
The results of my poll so far,

Looks like Harley figured out a way to get the single fire bikes to fart more than the dual fire bikes. Well mash my potatos, the new bikes are now only heavy as hell, but they run crappy too. Who would of thunk it. :wonderlan


Single fire ignition bikes that carb fart every ride, or at least once a week. 60%
Dual fire ignition bikes that carb fart every ride, or at least once a week. 50%

Single fire bikes that fart less than once a week 40%
Dual fire bikes that fart less than once a week 50%

Gone
29th October 2009, 07:38
My wasted spark (dual spark) bike never backfires, I had a miss the other day but it finally coughed a BT out the exhaust and everything was good after that...
:D

ReddTigger
29th October 2009, 14:17
I get the very rare carb fart with my dual fire ignition. Typically if the bike is very cold and I try to get on it early, it'll fart.. but not enough to cause any concern.. and it's so infrequent I forget about it until it happens..


Bike is in a great state of tune.

Coolride
19th November 2009, 01:05
Mine used to fart at least once every ride, now with single fire it's rare, and it starts up super fast, and I don't need to ride with the choke after it starts. Best money spent for sure, but I don't know if the high energy Accel coil has anything to do with it too.

BillieB
4th December 2009, 23:00
I have a single fire. Mine only farts because I don't allow it enough time to warm up properly before riding:doh...I believe this to be tru for all carbed engines. This should be no surprise to anyone old enough to have more experience with a carb over FI.:p

Lenster
4th December 2009, 23:42
When I DO get carb farts, it doesn't tell me to change the ignition...it tells me fall is here and I need to richen the idle mixture a tad...

:clap:clap:clap

Shu
4th December 2009, 23:43
The results of my poll so far,

Looks like Harley figured out a way to get the single fire bikes to fart more than the dual fire bikes. Well mash my potatos, the new bikes are now only heavy as hell, but they run crappy too. Who would of thunk it. :wonderlan


Single fire ignition bikes that carb fart every ride, or at least once a week. 60%
Dual fire ignition bikes that carb fart every ride, or at least once a week. 50%

Single fire bikes that fart less than once a week 40%
Dual fire bikes that fart less than once a week 50%
Doesn't it suck when your theory is sound but the test subjects screw up the data? :smoke

cc rider
4th December 2009, 23:54
i get a fart maybe every other ride sometimes every ride. sometimes not at all, but i can almost make it do it. i think that i might have a leak though. i already have a 45 jet in it with 3 turns out. although it is getting colder here in rhode island and we are sea level. so maybe a bit more richer might do it. if anyone has any suggestions please chime in.

cc