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Author Topic: Throttle advice please  (Read 1811 times)

WillW

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Throttle advice please
« on: April 09, 2010, 07:47:26 PM »
Another newbie question. I've been aware that the throttle take up on both my bike and the loan bike I've been riding today seems kind of sudden - grabby, if you know what I mean. So if I've been rolling down a slight decline, or just slowing down with the throttle closed, and no matter how gently I twist it open again, there's a very small amount of play, then a sudden jerky uptake.  Is this just me not yet used to the nature of the beast, or is it something which can be adjusted. I've taken up all the slack on the throttle cable adjuster - it's not that I'm winding it open too fast - it's more that it jumps from tickover to a couple of thousand rpm with nothing between - no gradual progression.
It may be that's how the electonics manage it, in which case ok I'll work with it. Or is there some way to adjust this?
How's yours?
Thanks.
Will
2010 Royal Enfield Electra (G5) DL

2004 Kawasaki W650
~ the best british bike they never made ~

Rusty

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Re: Throttle advice please
« Reply #1 on: April 09, 2010, 08:27:56 PM »
Will, you gotta stop posting stuff which might suggest that all isn't rosy in the land of USA (sorry I meant UCE).

Mine's the same, rolling on from a fully closed throttle isn't very precise. It lurches more than I'd like, bad news if your rear brake actuator shears at the same time.

The only adjustment is the large brass air screw on top of the injector unit, this controls the idle speed only. It's very tempting to adjust the allen (hex) screw with a locknut next to it (it should be daubed with a blob of paint), don't touch this screw. If you fiddle with this potentiometer adjustment you'll need the correct software to reset the mixture, dealers probably won't have it, it's too expensive.

Just add interesting throttle response to the list of 'foibles'.

WillW

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Re: Throttle advice please
« Reply #2 on: April 09, 2010, 09:02:27 PM »
Thanks Rusty, I thought that might be the case. I just wanted to know if it's lurchy by nature or just mine needing adjustment (I can do carbs - but electronics is alien).
Lurchy by nature I can learn to live with.
I don''t mean to suggest in any way that this bike is anything less than the love of my life. But I'm forty years on from last time I was on two wheels and perhaps a little obsessional about my first new wheels ever. The brake thing was unfortunate. It's forgotten. The foibles are fine, part of the art.
Honestly? I can't get enough of riding around on this bike, but there may be more questions. I'm a novice remember.
It'll all settle down.
« Last Edit: April 09, 2010, 09:30:32 PM by WillW »
2010 Royal Enfield Electra (G5) DL

2004 Kawasaki W650
~ the best british bike they never made ~

Rusty

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Re: Throttle advice please
« Reply #3 on: April 09, 2010, 09:45:03 PM »
I don''t mean to suggest in any way that this bike is anything less than the love of my life.

I know, I'm just teasing our (my?) cousins hoping that some of it gets through to RE and improved build quality is the result.

Yesterday evening I took a 30 mile ride around some of the finest countryside England has to offer. The sun was out, the sheep were looking after their lambs and the Lambourn horses were out grazing. There really wasn't another bike I'd rather have been on.
« Last Edit: April 09, 2010, 09:48:22 PM by Rusty »

WillW

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Re: Throttle advice please
« Reply #4 on: April 09, 2010, 10:08:16 PM »
I did something similar this very evening around the lanes and byways of Devon. My own bike will be home soon and I'm planning a run down to Cornwall, a nice mix of dual carriageway, winding B-roads, and lanes.
Roll on......
2010 Royal Enfield Electra (G5) DL

2004 Kawasaki W650
~ the best british bike they never made ~

Vince

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Re: Throttle advice please
« Reply #5 on: April 09, 2010, 10:09:01 PM »
     I have not had to adjust anything pertaining to the injection system on any of the G5/C5's I've sold. Please resist the urge to 'adjust". A lot of low speed jerkiness on any bike can be traced to a loose chain. Make sure it is properly adjusted as follows: Rotate the wheel as you observe the chain. It will tighten and loosen. THIS IS NORMAL. Find the tight spot. Sit on the bike and measure the free play midway between the sprockets, on the bottom run. Adjust to have 3/4 " to 1-1/4" play. That's actual play, not merely that you can force it that far. A little loose is better than a little tight. When you are done remeasure with you off the bike. Save this measurement and next time re-adjust to there so you don't have to keep climbing on and off the bike.
     As to your throttle cable, you must have some free play. Turn the handle bar lock to lock. Check at several positions and ensure that there is free play everywhere. If you have taken out too much play you may inadvertently rev the motor when you turn in your driveway.
     A lot of throttle response issues can be traced to clutch control. In the situations you are having a throttle issue, try to work the clutch. Lightly and smoothly dis-engaging and re-engaging the clutch will smooth out throttle response.
      Try this stuff. I'll bet it will help.

WillW

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Re: Throttle advice please
« Reply #6 on: April 09, 2010, 10:12:45 PM »
Thanks Vince. I'll see how the bike is when back from 1st service any day now. Chain adjustment hadn't occurred to me in this context. I'm saving your post for future reference.
2010 Royal Enfield Electra (G5) DL

2004 Kawasaki W650
~ the best british bike they never made ~

singhg5

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Re: Throttle advice please
« Reply #7 on: April 10, 2010, 03:47:19 PM »
Will:

Vince has very good suggestions for your throttle symptoms.  Besides that, your bike's throttle cable may be sticking a bit and need some lubrication.  Unless the real cause of the problem - that may be from sticking cable, to clutch control or chain adjustment - is identified and confirmed, I would not adjust the throttle play because you need some play in the cable.

Hope your bike comes back soon and you can enjoy the summer rides and share your trips.  
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2009 Royal Enfield Black G5

Chasfield

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Re: Throttle advice please
« Reply #8 on: April 10, 2010, 04:21:14 PM »
Emission regulations have compelled vehicle designers to lean down fuelling to what would once have been unworkable levels. Remember, the lean burn AVL engine wasn't lean enough for the Eurocrats. I don't think any modern motorcycle wil give you the instant torque response from low revs that you would once have taken for granted. With modern vehicles the EFI unit's first response to a handful of throttle is "Buddy, I sure wish you hadn't done that". Maybe later it will deliver some fue/air mix, after you have had time to calm down!

30 years ago (gulp) I was running a Triumph 650 twin along side a brand new Honda 250 single. The Triumph gave the impression that the throttle cable was directly hauling the bike along, right from tickover. The "modern" Honda, on the other hand, was set up ultra lean, and even though the carb had an accelerator pump, if I opened the throttle enthusiastically, the engine just got left behind and gasped. It fuelled nicely once there were some revs on the clock and the motor could get on the cam and move some air.

I think even current models of Moto Guzzi twin have to be stirred up a bit before they pull cleanly, whereas on a 1970s/1980s Guzzi you would have just leaned on the engine torque.

Of course, the up side to all of this is that the EFI Bullets are amazingly frugal with fuel.
« Last Edit: April 10, 2010, 04:34:12 PM by Chasfield »
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WillW

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Re: Throttle advice please
« Reply #9 on: April 10, 2010, 04:33:31 PM »
I'm pretty sure that what I was experiencing is loose chain jolt. I had my first 100 mile ride today - on the loan bike, not my own, and the problem is significantly worse than on my bike, and sure enough, inspection reveals a chain with a lot of free play - confirmed by a biker pal I dropped in on as I headed home. I'll have a tinker with it tomorrow.
But what a day for it!  Thudding round the Devon coast in the sunshine - I think every biker was out and about today. But yikes, that saddle on the loan bike - Bullet Classic. My arse is paralysed!  I waaaaay prefer the dual seat on my Electra.
Thanks for the input guys, gratefully received.
2010 Royal Enfield Electra (G5) DL

2004 Kawasaki W650
~ the best british bike they never made ~

UncleErnie

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Re: Throttle advice please
« Reply #10 on: April 10, 2010, 10:02:56 PM »
I belive what you are experiencing is called "chain snatch".   Rather disconcerting.
Run what ya brung

chinoy

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Re: Throttle advice please
« Reply #11 on: April 11, 2010, 07:10:48 AM »
what your experencing has nothing to do with the cable or the chain.
Its called low speed surging.
And its there on the Indian and the Export Modell of the C5/G5.
The reason your being told not to adjust anything is because. Playing with the adjustments is not going to help resolve this problem but ma create new ones.

Just learn to live with it.
Untill somebody comes out with a better ECU.


WillW

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Re: Throttle advice please
« Reply #12 on: April 11, 2010, 07:53:14 AM »
Hmmmmm....  Well, learn to live with it had already been my conclusion, but not until I'd established it was indeed an Enfield foible, and not a thing I could fix. Naturally one wants to know the WHY of these things.
But there's no doubting the chain is a bit to slack on this current bike, and I'll see how mine is when it's back from 1st service, tomorrow I hope. The snatchiness was first noticed on my own bike, though slight, but way more so on the loan bike, which does have the slack chain. I'll have a go at tightening it today and note the difference if any.
With regard to torque response, it's fine, very satisfying, to this newbie at any rate.
I've not been aware of any surging at low speed on either bike. It's just that the transmission take-up from no throttle to low throttle is a jump rather than a progression, if that makes sense.
« Last Edit: April 11, 2010, 07:55:35 AM by WillW »
2010 Royal Enfield Electra (G5) DL

2004 Kawasaki W650
~ the best british bike they never made ~

Kevin Mahoney

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Re: Throttle advice please
« Reply #13 on: April 11, 2010, 08:25:05 AM »
I agree with Vince. The only time you might feel anything funky with the EFI is the first 60-90 seconds after it starts from cold until the oxygen sensor kicks in. An EFI bike especially a single may not run lean at all. In fact when it starts it is a bit on the rich side. With a carburetter bike (any carburetted bike) your mixture is a combination of mechanical inputs that are gauged to more or less be right. With a closed loop EFI unit the mixture can be made perfect under all conditions. This means that you can run at the idea A/F mixture for each condition. Also bear in mind that a 500cc single has less blowing out the tailpipe than a 750 twin yet both are held to the same standard.

When a new EFI system is programmed it has to have an answer for every possible condition - this is literally millions of different combinations. Normally the first MAP that is developed has some glitches somewhere that are borne out by road testing or actual real world conditions. Our MAP was almost perfect the first time. There were some cold weather/altitude issues that were ironed out before the final MAP was approved.

IMHO any "snatching" you are seeing is mostly likely the fault of a chain tension and there is only a remote chance that it has anything at all to do with the EFI unit or related parts.

As someone else mentioned, under NOT circumstances should you adjust what appreads to be the idle speed on the throttle position sensor.






e

WillW

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Re: Throttle advice please
« Reply #14 on: April 11, 2010, 08:51:58 AM »
Thanks. I too agree about the snatchiness being because of the chain. I have no issues with the way the bike responds otherwise,  and trust me - messing with the electronics aint going to be happening in this man's garage!
2010 Royal Enfield Electra (G5) DL

2004 Kawasaki W650
~ the best british bike they never made ~