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Engine stutter!!!!!

11K views 41 replies 18 participants last post by  aceofspades 
#1 ·
I installed the vance and hines twin slash staggered a few weeks ago. The pipes sound awesome, but i have noticed a engine stutter around 35mph in 2nd gear. I had done the o2 mod and took it out to see if that would correct the problem, which it did not. Any ideas or anyone else have the same problem?
 
#3 ·
Thanks tony. I am eventually changing my air intake and getting an autotuner. Im hoping that will fix it. But i am not gonna do that till late fall and was wondering if there was a quick fix until then.
 
#6 ·
So the problem isn't the clunkiness in low rpms in second gear. It's almost like the bike is misfiring while staying constant on the throttle at around 35-40 in second gear. It also does it in 1st around 20 mph. Havent noticed it in any other gear. It's really annoying especially on on-ramps and off-ramps.
 
#8 ·
I had the mod before i put the exhaust on. When i noticed the issue, i took the resistor out and same problem. I see a auto tune in my near future.
 
#9 ·
I have that same problem. first let me state that iv got the V&H twin slash , the Cobra Power Flo intake, and the Cobra PowrPro AutoTuner - and the bike was doing this only in the 2nd gear cruising at 35mph... Well I took off the PowrPro and sent it in to be fixed / reparied.

I ran the bike and it got worse without the tuner - now experiencing it in 1st gear and 2nd gear like you... So, I unplugged the O2 sensor from the bike and while it still stutters / chuggs / surges - it's no where near as bad as when the sensor was plugged in.

So, I'm hoping that when I get my Tuner back - it will solve those little nagging issues, - I'll leave an update when I know more.
 
#11 ·
just a note that 86 or 87 octane runs best in this bike. Not sure what you are running.
 
#12 ·
I used 93 for the first year i had the bike and have since then ive used 87. Thank you for all the help. I thought i was going crazy.
 
#16 ·
I know this is an old topic but I was wondering if anything had been figured out. I just got my bike and I have V&H big radius, low & mean performance air intake, and V&H fuel pack. The stutter is driving me mad. It happens in both 2nd and 3rd gear (more so in third) any time I hover around the 40mph mark it acts like it wants to die if you don't give it throttle. If I lay off it for even a second I worry. Surely there has to be a solution!
 
#17 ·
bds369 -

Unfortunately there has not been one solution to fit all cases. It seems that there are just enough variances in our bikes to make them "unique" in terms of figuring out a solution. I'm surprised to hear though that your V&H pipes are not playing well with your V&H tuner.

I hate that stutter as well, drives me crazy ! I have it in every gear ... there is just a certain "cut-off" - in the RPM range for each of the gears that will cause it stutter - & spit. So, I'm replacing my V&H - with some Cobra's tri-pro's.. and see if that helps... and if not then i'm replacing my Cobra PwrPro tuner for an EJK tuner... and if all that doesnt work... then I don't know what I'm going to do other than having to shell out for a power commander and getting it dyno'd and tuned in. *shrugs*

Do, have a question for ya tho, with that V&H fuel pak - can you change the settings on it? (what settings is it at and what have you tried adjusting it to?) or is it a plug n play?
 
#18 ·
There are quite a few settings in the fuel pack that you can change. (at least 20). Its a small lcd with a few buttons to change the settings. They give you a base map and then you tell them what equipment you have and they give you the recommended map for your bike. I happen to have the dealer put mine in but I know how to change them. I don't have my current settings written down but I'll look at it tonight. I haven't contacted V&H yet on this issue but I suppose I could if I still get nowhere on it. It obviously isn't specific to this hardware, it happens even on a stock bike.
 
#19 ·
I have a PC5 on mine with Powrflow intake and Twin Slashed exhaust and it runs awesome but has that stutter when you are flat on the throttle in second gear about 30mph. I am about a month away from my dyno tune so we will see what that does for it.
 
#35 ·
I have the V&H twins, Cobra Powerfo Air Intake and EJK. I have recently changed to 87 octane also. I get very little stutter these days holding med-high revs in the lower gears, and minimal backfire.
I experimented with the EJK - stock settings / 2-4-3 / 2-5-3 and plenty more (was a lot of fun actually). I read on this forum that the most popular is 3-2-2 which didn't sit right initially as I wanted more acceleration. But they were right 3-2-2 provides a great balance with minimum stutter and backfire.
Mind you I can't help myself so I will try to up the acceleration, but if the stuttering / backfire goes to crap again I'll just revert back.
I still get the chugging taking off at lower gears which is a right royal pain so I may look at a 30T pulley, but as I live in the country I'm mainly highway driving so it's bearable.
Hope this helps.
 
#22 ·
THIS definitely helps.
BUT... With Cobra pipes, Cobra intake and Cobra autotune my stuttering disappeared entirely when I simply disconnected the o2 sensor.
Problem solved, kaput!
The o2 mod did nothing IMO but unplugging it doe the trick.

I have heard nothing good about using the Cobra Auto~tuner with V&H pipes though.
It's harder to get the two to play nicely together.
 
#29 ·
Exactly what happened to me Thought all was great and then about 100 miles, same exact thing as you.
 
#26 ·
I tried disconnecting mine and the stutter was still there. With the 30 tooth pulley change wouldn't that really only work with the 210 tire because once you put a 240 on it wouldn't the overall gear ratio be about the same as factory.
 
#27 ·
No, I have the 240 and the 30 tooth was noticeable.
You're talking about primary drive and percentage of travel in the belt over the diameter of the pulley. Remember, you are not changing the rear pulley, it stays the same. The extra diameter of the tire is minimal.
The massive torque this beast puts out overcomes the minimal change in tire diameter.

I really noticed the stammering of the bike in town at @ 35 in 2nd gear but no more after the 30 tooth and the 240.
 
#34 ·
Do have stock air and or a tuner. I still have stock air and no tuner. I swapped out my o2 sensor for a wide band sensor so I would know what my A/F ratio is. I have no issues at all but did notice it started to run richer at stops, later in the season last year. About 12.4:1. I think it is because of the air filter getting a little dirty. I will find out when I get her out. Still to much dame snow.

I have the autotuner and the cobra powerflow air cleaner...


Disconnect 02 sensor, install PowerFlow and EJK Tuner and your problems will go away!
I have thought about selling my autotuner and buying a EJK tuner to try it out but don't want to buy it and have it not work either
 
#38 ·
BUT...
If you can't get your hands on $350 then a viable solution for a lot of it is adjusting ALL the slack out of your throttle, (Make sure it returns easily), disconnect your O2 sensor and spending $100 for the 30 tooth pulley.
Money's tight, Not everyone can spring for the Flash.

But having gone that route myself initially I would add that Ivans flash is really the way to go if you can afford it.
 
#40 ·
what did any of u notice in terms power gains from the flash?
The two most important days in your life are the day you are born and the day you find out why." - Mark Twain
You can go to his websight and find actual Dyno sheets on it but for me the real plus is the torque, THAT is noticeable without the Dyno.
I can roll on the throttle hard and have a hard time keeping my arms bent!
The throttle is much smoother incrementally rather than feeling like an "On-Off" switch at cruising speeds.
The stutter is completely gone, so is the decel popping.
The bike should have come from the factory this way and probably would have if Yammy didn't have so many Import rules to abide by for environmental concerns.
 
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