[TBissonnette]

Hi all sorry i haven't posted a new thread in a while i have been on vacation and me and the wife's anniversary is the 17th so we took a early vacation much needed to . But anyway back to business my rc51 bucks at low rpm's i always have to down shift and its driving me crazy i am teaching my wife how to ride and as we are riding around my neighborhood it bucks all the time a low rpm's is there anything i can do to stop it, someone said that if i get a powercommander III and get it set right it will fix the problem does anyone know if that is true or not and if it is not what can i do to fix it???

[zerogara]

At what rpm is this happening?
Have you disabled/removed the flapper?

[Chum]

Originally Posted by TBissonnette

i am teaching my wife how to ride

Not sure thats a good bike to learn on. Just a thought.
As far as the power commander question goes, I cant say from experience but I've heard it smoothes things out at lower RPM.

[jrivas]

hey chum i thought you were in heaven waiting for me!! you are alive!!

[Chum]

Yeah, I've been around. Glad to see your enjoying your bike.

[zerogara]

I think he is riding close to his wife who rides that 250 he has in the picture, so HE is going slow not to make his wife uncomfortable, I think!
I once was on a high bridge at heavy traffic and it was hot and sunny and despite of what the law says I decided to creep between lanes to get out of the heat. While lugging at the top the motor stalled but I had enough rolling momentum to make it to the down slope. Still on heavy traffic I decided to let it cool off while rolling and close to the bottom pop second gear in and jump on it! Worked on every 4cyl I ever tried it on like a charm. Lesson learned, the rear locked solid and started coming out the side, clutched it and jumped even harer while I popped it again! Not one degree of rotation
I'm glad that starter worked while I was making a fool of myself
Maybe if you are doing 50mph and weigh 300lb you can get it started that way!

[TBissonnette]

Yes i am not the one learning how to ride its my wife on the 250 but i am trying to stay close to her until she feels comfortable enough to pull away from me. the bucking happends under 2500 rpm at really slow speeds just wondering if there is something i can do to fix it

[zerogara]

There is very little power down there, it all starts at 3k. Disabling the flapper may help a bit. All you have to do is pull the little vacuum hose from the round canister and plug it up well (rubber plug or small screw will do it but by no means do not run the engine without it being plugged well). This leaves the flap wide open. If you go to the ROGUE site you'll find instructions on how to remove the whole thing.
It may help a little down low but you will be the judge. It is not good to run the engine so low anyway. Maybe run it on lower gear and feather the clutch a bit to avoid jerking on/off.
Don't tell me she is going so slow that first gear at 2500rpm is too fast for her.

[jkobflys]

TB the engine idles at 1300rpm. so theres allways going to be "bucking" at that rpm.
Use the clutch and feather the throtle like Zerogara said.

[UKRC51]

Hi TBissonnette,

I use my RC51 every day to commute on, and i have found that around 28 mph in second approx 2800 rpm mine does the same. If i keep it at 2500 rpm it does'nt seem to do it and again at 3000 rpm. It seems to me the fuel scheduling doesn't seem to like this area of rpm to run in, so you find you are constantly on the throttle then backing off etc to try and maintian that speed. I would also like to know if there is a solution to this as i dont know if its the power commander or just the way the bike is.

Gary

[UKRC51]

Just a thought, you could always buy another set of sprockets to alter the gearing if you will be riding at these speeds for a while in order to make bike rev a bit more, to keep you out of that rev range.

Gary

[jtingle]

Buy a power commander with a mapping for whatever exhaust you have. I had my PCIII die on me and I rode without one for about a month before I got tired of the twitchy throttle and bucking at low rpm's. Got a new PCIII and everything is smooth as butter again. It makes all the difference.

Gearing change might help a bit too. I use 15/42 and it makes the bike more usable on the street. I had 15/41, which is popular too, but I thought it was a bit tall.

[HRC RC51]

power commader will smooth out power as you climb in revs, but at a few miles an hour pacing a new rider, it wont do a thing. It is a race bike and going slow isnt in it's "nature" so pulling in the clutch an coasting like in slow traffic conditions would be best until she is up to speed.

[zerogara]

This is true, wild cam timing/duration/travel make some engines want to rev past some rpm and are dogs at low speed. You can't have the best of both worlds. When you hear an engine laboring try to stay at idle it is most likely one with cams set to rev high.
Have you noticed how this engine doesn't like to stay at steady speed, it is either slowing down or accelrating? Pain in the neck in legal speeds as it is only comfortable doing over 100mph (160kph). I can imagine those with low gearing (like 15/41+) must be acting like wild goats in traffic

Originally Posted by HRC RC51

power commader will smooth out power as you climb in revs, but at a few miles an hour pacing a new rider, it wont do a thing. It is a race bike and going slow isnt in it's "nature" so pulling in the clutch an coasting like in slow traffic conditions would be best until she is up to speed.

[jtingle]

Originally Posted by HRC RC51

power commader will smooth out power as you climb in revs, but at a few miles an hour pacing a new rider, it wont do a thing. It is a race bike and going slow isnt in it's "nature" so pulling in the clutch an coasting like in slow traffic conditions would be best until she is up to speed.

I respectfully disagree. I have a 2004 RC that had the same problems at low rpms without the PCIII running on it. I have Sato low mounts as well which made the issue even worse without the mapping the PCIII uses. I put another PCIII on and I can rumble around in slow city traffic with no problems. The PCIII completely smoothed out the throttle response.

[zerogara]

If you look at almost all maps for the RC in the low revs and all throttle openings it is + + + big numbers. It is very lean down there, probably for meeting emissions rather than perform. As silly as the EPA and EURO demands are for smog you can program around them. But twins are harder to ride in some respects than 4s and this lean condition down low makes them a bit more civilized, when their true nature is to tear up asphalt. Given that they don't have a slipper clutch being lean down low is a safety issue as well.
That's my interpretation of what is going on, I welcome other explanations.

[TBissonnette]

thanks for all your posts guys alot of info i need to let soak in i deffinetly will go out and buy a powercommander III

[jesse954]

you could buy a bicycle until she's ready to get up to speed

[pbc0]

You might want to try checking the setting of the throttle position sensor. If its not set properly then the ignition timing might be a little bit to advanced for the rpm's your trying to ride on. This does make a difference at lower speeds and stops the bucking, defo.
I thought it was bollocks till I tried it on my old Varadero (not the same engine, but pretty closely related).
Smooth running at low revs is just as much down to correct ignition timing as fuel mapping.

Just a thought.

[zerogara]

Good idea, but can this sensor be adjusted? It may be mulfunctioning and what Pbc0 says makes sense.

[pbc0]

The throttle position sensor is adjustable. It should be set to about 500 ohms at idle position.
If its higher than that then the ECU will advance the ignition more than it should be at tickover and will over advance all the way until maximum advance. You don't really notice it until you try to ride in the low rev range.
Makes the bike more forgiving when you're exiting a corner in higher gears.
Its got two tamperproof screws fastening it.
I just took mine out, binned them and fitted capheaded allen screws.

[pbc0]

And if this sensor fails or you disconnect it the the ECU defaults to control the ignition advance off engine RPM's only.

So Try just disconnecting it to see what happens. Should run smooth but gutless when you give it some rice.

[SubSailor]

Harley's don't rev to 10.2K RPM and RC51's don't chug.
Keep the bike above 3500 RPM and you won't have problems.
It's the nature of the beast. It's designed to rev, not putt.

[TBissonnette]

You guys are all Right its not made to Putt Putt around and for whatever reason that you are going slow you have to play with the clutch. thanks for all the info i will try them

[CBR400RR]

The RC51 is not ment to be ridden below 3K but if you do the pair, flapper, soft rev mods and 15/41 gearing with a set of slip-ons and a PCIII USB it makes the bike feel compleatly diffrent and a lot easier to ride and a lot mor fun.

[Bigtoe]

Originally Posted by SubSailor

Harley's don't rev to 10.2K RPM and RC51's don't chug.
Keep the bike above 3500 RPM and you won't have problems.
It's the nature of the beast. It's designed to rev, not putt.

[setanta]

Originally Posted by jesse954

you could buy a bicycle until she's ready to get up to speed

Oh shame that was ignored it made me giggle

[zerogara]

Or a little monkey bike chasing your biker wife around on it
Don't forget to wear knee draggers while going around the neighborhood.

[Suum Cuique]

One of the quirkes of the bike I thought. I got used to it after a while and it doesn't really bother me now, I just tend to give a little extra revs when I'm expecting the ole heebee-geebees to kick in.

[Wheeliest]

feather the clutch.