Wilsons Sandbox

At 02:17 PM 10/11/2003 -0500, you wrote:

>Why would you not want quicker response? I like it myself (being an old 2

stroke rider).

> >Criswell >

You need to go back and read the original letter. It all depends on riding style. Old two stroke trials bikes had very heavy flywheels to slow response so the rear wheel had less of tendency to break traction, engines were very mildly tuned for the same reason. The heavy flywheel also meant the engine was harder to stall. Seems to me that trials riding started to change during the late 70s. Alan Henderson A13 Iowa

Picture this: You go over the lip and down a 20' loose gravel descent into a wash and you know the climb back out is a u-turn out of deep sand and up an old mining road. The turn exit is obscured by some overhanging branches and you know the bike will be nearly impossible to get rolling again if you stall it in the turn. The climb is nastily steep - two well-eroded ruts with base-rock showing through and littered with decomposed granite gravel and larger rocks. The right hand rut can be ridden with speed but the left hand has very large boulders lodged in it. Mid-way up the right-hand side however, there is a huge step that should not be tried but there is room to get by on the left. A precise maneuver will be needed at the base of the step. Flywheel effect assists to negotiate this in several places. In the descent, the clutch can be left out and the mass of engine rotating parts will be reluctant to chuff-out if too much rear brake is applied. Then in the turn, if the rear tire starts to break traction in the sand, the throttle can be carefully modulated in that sweet zone between dig-in and last gasp. On the climb, the throttle will need to be shut off at the top of the right-hand burst and carefully applied in the small s-turn to change lanes around the step. Forward momentum will be lost and the engine will be asked to gather rev's once again in that sweet spot - no tire spin or 'looping' and gradual, traction finding acceleration. Does this seem familiar? I think the KLR has either quite satisfactory flywheel effect or else it is just so strong that, at minimum bangs per second, it seems like it. At the same time, it accelerates nicely without the feel of heavy flywheel and shuts off right now. It reminds me of my last bike (SV650) where I always warned fellow riders to watch out for big time deceleration without brake light warning. I'm very satisfied and, although it has limits, the big bike does what is asked of it in tough situations. -Jim in AZ

----- Original Message ----- From: "Alan L Henderson" To: DSN_klr650@yahoogroups.com> Sent: Saturday, October 11, 2003 8:53 PM Subject: Re: [DSN_klr650] Re:more carb jetting NKLR > At 02:17 PM 10/11/2003 -0500, you wrote: > >Why would you not want quicker response? I like it myself (being an old 2 > stroke rider). > > > >Criswell

Jim The Canoeist wrote: [...]

> I think the KLR has either quite satisfactory flywheel effect or else it is > just so strong that, at minimum bangs per second, it seems like it.

Plenty of times when I have had my bike tilted right over at near idle speed I could feel the back end twitch out a bit with each power pulse once the throttle was opened up. It is what a 600 single does, original big-bang theory. If you routinely get into trials situations then it might be useful to disable the KACR to reduce the chance of stalling at below-idle revs. You can ride through an activated KACR, I have done it, but it takes a lot of throttle and the exhaust valve and seat under the KACR won't thank you if you do it a lot. Mister_T Melbourne Australia

Is there an easy and reversible way to disable the KACR? Volker -----Original Message----- From: sentto-488385-84360-1066054832-vtraudt=compuserve.com@....c om [mailto:sentto-488385-84360-1066054832-vtraudt=compuserve.com@... .yahoo.com] On Behalf Of Ted Palmer Sent: Monday, October 13, 2003 10:17 AM To: 1KLRlist Subject: Re: [DSN_klr650] Re:more carb jetting NKLR Jim The Canoeist wrote: [...]

> I think the KLR has either quite satisfactory flywheel effect or else > it is just so strong that, at minimum bangs per second, it seems like > it.

Plenty of times when I have had my bike tilted right over at near idle speed I could feel the back end twitch out a bit with each power pulse once the throttle was opened up. It is what a 600 single does, original big-bang theory. If you routinely get into trials situations then it might be useful to disable the KACR to reduce the chance of stalling at below-idle revs. You can ride through an activated KACR, I have done it, but it takes a lot of throttle and the exhaust valve and seat under the KACR won't thank you if you do it a lot. Mister_T Melbourne Australia List sponsored by Dual Sport News at www.dualsportnews.com. List FAQ courtesy of Chris Krok at: www.bigcee.com/klr650faq.html Unsubscribe by sending a blank message to: DSN_klr650-unsubscribe@yahoogroups.com . Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

Volker Traudt wrote:

> > Is there an easy and reversible way to disable the KACR?

[...] Just removing the spring should be a good start. Maybe something a bit more involved would be to move the weights out as far as possible and drill a hole through each weight and into the plate underneath, the put a small rollpin through each hole. Mister_T Melbourne Australia

I'm confused. Isn't the KACR only energized when the starter is engaged? Are we learning that it also releases compression at low engine rev's? Are you telling me I am damaging something by going real slow with the clutch out and then applying throttle? Is the automatic compression release energized during this? I want to be sure of this. Is there somewhere where we can read the theory and operation of the KACR? -Jim in AZ

----- Original Message ----- From: "Ted Palmer" To: "1KLRlist" DSN_klr650@yahoogroups.com> Sent: Monday, October 13, 2003 7:16 AM Subject: Re: [DSN_klr650] Re:more carb jetting NKLR > > Plenty of times when I have had my bike tilted right over at near idle > speed I could feel the back end twitch out a bit with each power > pulse once the throttle was opened up. It is what a 600 single does, > original big-bang theory. > > If you routinely get into trials situations then it might be useful > to disable the KACR to reduce the chance of stalling at below-idle > revs. > You can ride through an activated KACR, I have done it, but it takes > a lot of throttle and the exhaust valve and seat under the KACR > won't thank you if you do it a lot. > > Mister_T > Melbourne Australia

In a message dated 2003-10-18 4:48:16 AM Pacific Daylight Time, a14@... writes:

> > The KACR is located on the end of the exhaust cam. It is controlled > by weights which must overcome spring tension with centrifugal > force. In it's static position there is a pin which is located next to > the right exhaust cam lobe which causes the valve to open earlier > thus releasing compression. It stays this way at starter motor speeds > and once running the weights swing out pulling the pin out of the way. > If you let the engine speed drop too low the weights will be pulled in > by the spring and the pin will begin to release compression. This will > cause hot exhaust gases to pass by the right exhaust valve seat excessively > which can overheat the seat in the head and on the valve, allow deposits > to form and eventually can cause them to burn. > > Walt > A14 "War Horse" > >

How low is too low? I wouldn't think the weights would swing in until some where well below idle speed if the weights swing outward with anything over starter speed. Pat G'ville, Nv [Non-text portions of this message have been removed]

The KACR is activated by centrifical (sp?) force. Like the old Mechanical advance on your cars distributer. Its a mechanical device that starts working at low RPM when centrifical force is low. Without taking a look at it. A guess would be to remove the springs to disable it. --- In DSN_klr650@yahoogroups.com, "Jim The Canoeist" wrote:

> I'm confused. Isn't the KACR only energized when the starter is

engaged?

> Are we learning that it also releases compression at low engine

rev's?

> > Are you telling me I am damaging something by going real slow with

the

> clutch out and then applying throttle? Is the automatic

compression release

> energized during this? > > I want to be sure of this. > Is there somewhere where we can read the theory and operation of

the KACR?

> > -Jim in AZ > >

This is exactly my point (how slow?) but I read where others warn about the system energizing at low speeds and having experience 'driving through it', etc. I have often gotten the engine below idle speed in tight situations. That was not low enough for the engine to chuff-out of course but I'm wondering if low enough for a compression release to mess with things. Obviously, I am very worried and must learn the real story & no guessing. It appears that this device is digital, i.e., it is either in or out, depending if those weights are rotating fast enough to disengage a pin or allow it to return to its static position. The issue is whether or not this occurs at operating rev's (albeit, below the idle speed). The engine should not be operated with the compression released because exhaust gasses are being released where they can do damage. Does anyone know what the symptoms are for when the compression release activates while the engine is running at very low RPM? If there were some detectable sound or other signal, I could experiment with a running engine and the idle stop. -Jim in AZ

----- Original Message ----- From: KDXKawboy@... To: a14@... ; DSN_klr650@yahoogroups.com ; jwalsh21@... Sent: Saturday, October 18, 2003 6:46 AM Subject: Re: [DSN_klr650] Re:more carb jetting NKLR In a message dated 2003-10-18 4:48:16 AM Pacific Daylight Time, a14@... writes: The KACR is located on the end of the exhaust cam. It is controlled by weights which must overcome spring tension with centrifugal force. In it's static position there is a pin which is located next to the right exhaust cam lobe which causes the valve to open earlier thus releasing compression. It stays this way at starter motor speeds and once running the weights swing out pulling the pin out of the way. If you let the engine speed drop too low the weights will be pulled in by the spring and the pin will begin to release compression. This will cause hot exhaust gases to pass by the right exhaust valve seat excessively which can overheat the seat in the head and on the valve, allow deposits to form and eventually can cause them to burn. Walt A14 "War Horse" How low is too low? I wouldn't think the weights would swing in until some where well below idle speed if the weights swing outward with anything over starter speed. Pat G'ville, Nv [Non-text portions of this message have been removed]

Thank you Walt. How do you know the compression is released at 800 RPM? What is the indication? -Jim in AZ

----- Original Message ----- From: "Walt" To: ; DSN_klr650@yahoogroups.com> Sent: Saturday, October 18, 2003 7:22 AM Subject: Re: [DSN_klr650] Re:more carb jetting NKLR > > How low is too low? I wouldn't think the weights would swing in until some > > where well below idle speed if the weights swing outward with anything > over > > starter speed. > > > > Pat > > G'ville, Nv > > > > > > Well on my bike it is around 800 RPM but I would suppose > every bike is a bit different due to build variations and wear. > Believe it or not but I can get my bike that low without lugging > or shaking until the KACR kicks in when I want to be in stealth > mode even with a 16 tooth front sprocket. I can even pull a > moderate hill with a heavy load at 1000 RPM which is usually as > low as I go but only in first gear of course since when in a higher > gear I can downshift and otherwise keep it above 2000 RPM. > Keep in mind that this is with applying very light throttle and when > acceleration is needed or at the first hint of lugging I pull in and > feather the clutch while applying the throttle to speed up. > > Walt > A14 "War Horse"