Engine misses a beat and the rde is 'jumpy' ???

[aalsalem]

My 2009 NightRod Special has V&H Black Widows and a K&N air filter fitted. It has 10,000km on it.

The bike starts up good and once warm it ticks over ok.
However as I change up from 1st through 3rd and gradually increase speed the engine misses a beat and the rde is 'jumpy'.
Once I get up to around 60km/Hr it smooths out and is a real pleasure.
Acceleration is good.
The end caps on the mufflers do get coated in black soot after around 150km running.

The real annoyance is when going around corners or at roundabouts when, if I let the revs down to 2000, in 2nd gear the bike misses a beat and it is actually a bit dangerous as it sends you off line. If I snath the throttle open the bike responds good but if I open the throttle slowly, it coughs and misses a beat as speed increases. Filtering through traffic is uncomfortable unless I keep the revs above normal and slip the clutch.

I have asked the dealer to sort it out but they are not too good down here. I think it is something like an over-rich mixture or a blocked filter as it is the sort of thing you get if you leave the choke out. If it was a carb bike I would say there is a problem with the progression circuit that increases fuel between idle and acceleration or ther is an air restriction.

Also there are two rubber O Rings on the velocity stacks that I can see if I remove the air box cover and air filter cover. They appear to seve no purpose, and I can slide them up and down the stacks, leaving them wherever I want to, what do they do?

Also there is some sort of sensor at the left hand, forward top of the air box cover, any ideas what that is for?

It is a great bike and really does make me smile when I ride it but if I could smooth out the running it would be perfect.
HELP.

[bcrichard]

The sensor on the front air box cover is an IAT (intake air temp), the rubber "O" rings on the stacks are just a safety device to prevent the stack's bolts from getting sucked into the intakes should they ever come loose. Since you are running non-stock pipes and air filter I assume you are running some sort of after market fuel management or tuner device, so  if your end caps are getting black soot it sounds like an over rich set up and needs a proper mapping. (Good investment is a shop manual) 

[glens]

What's that thing called on the HDI bikes that operates a flapper in the airbox?

[harborjohn]

The Revolution Engine does not like to run at 2000 rpm or lower. My V-Rod will buck and kick at 2k rpm but will smoth out at 2200-2600rpm. Its a High rpm motor and should always be kept above 3k rpm. As you know the V-Rod Engine doest really wake up till about 4500rpm and starrts to sing at 6000+rpm

[No Regrets]

You need to get it on the puter... And watch it at 10,20. and so on throttle. If your going to keep the bike get a tuner any brand you prefer..... The only way to work on these bikes... And simple.... Mine hated 5200 RPMs witch sucked because that's cruising speed for me about 70-75 MPH. Put it on the tuner tweak the air/fuel...... Watch Out............ Hope this Helps

[rbonner]

My VRSCR does exactly the same thing.  I drilled out 8 -  1/2" holes in the rear of the stock mufflers.  When I had 8 - 3/8th" holes the EFI could handle the change, but the larger holes went out of its range.

Black soot is just black soot...  I checked the plugs and mine are very light gray, running too lean.  When the bike gets the RPM up it runs fine, but everything in the 3000 - 4000 range is weak.  You shouldn't be doing any cruising on a V-Rod below 3000 RPM, it too far out of its torque band.  Back in 1976 my Kowie KZ-900 was the same way.

Right now my Rod is parked at the HD dealer awaiting service on their dyno.  The fix will be a tuner and enrichening the bottom end to throw more fuel at the free-er breathing engine.

Sorry this is such an old thread.  I just got my bike out of storage.

BOB

[rbonner]

Got the bike back from service; they installed an UPDATED EFI map from the factory on mine.  Free update, 109 bucks to install.  Bike misses while cold still, but after warmed up it is perfect now.  VAroom.  About time.  And all I did was open up the exhaust some to cause the problem.

Answer: The addition of adjustable fuel map device of sorts and a dyno tune.  Get the programmer out.

BOB