Can anyone tell me how to adjust or reset or check my engine breaking on my Prairie 650. I can hear the actuator aligning itself each time I start up and shut off the quad. The engine breaking seems to work until the eingine rpms drop down to around idle. If I bump the throttle it will engine break for a little while until the rpms drop back to idle. Besides when going down a hill I don't want to bump the throttle. I used to work correctly.

Any ideas???

 

Misadjusted shift lever, loose engine mounting bolts?

 

The KEBC functions to keep the effective radius of the DRIVING pulley of the clutch at a point which causes the effective transmission ratio of the CVT (clutch) to be lower than it would be, if no engine braking was required, and this "low" ratio makes the wheels try to turn the engine against its compression, rather than vice versa.

If the drive belt is slipping, then there is not enough coupling of the forces causing the tires to rotate to the engine's compression resistance. From your post, it sounds like the problem you have is being caused by too much belt slack (belt deflection) and all that you need to do is adjust the belt deflection to meet OEM specification to correct this problem. You do this by adding shims to the driven pulley. You need to read up on how to do this and you need some special tools, if you do not want to go to a dealer. If the problem it is not caused by the belt deflection adjustment, then there may be something out of whack with the KEBC actuator motor postion, the computer, or the KEBC actuator linkage.

All that the KEBC system does is to push a forked lever against the outer collar of the driving pulley's center bushing, thus preventing the driving pulley from expnding to open up the distance between its inner and outer sheaves. In effect, this forces the clutch pulley ratio to take a "low gear" position, rather than allowing it to shift to a "high gear" position, (as it normally would) when engine RPM increases. It is the same effect as you get when downshifting a car transmission, instead of putting on the brakes, when you want to slow down.

Since, in a braking situation, the engine is not delivering driving power to the wheels, the wheels must then turn the engine (faster than the engine wants to go). This is how the compression braking effect is created. The KEBC system uses a computer to determine how much pressure the engine braking lever (located inside the belt cover) must exert against the inner bushing of the driving pulley to create the "downshifting" braking force. The KEBC computer does this by comparing several parameters, such as engine RPM and throttle setting. When this computer senses that the throttle setting is lower than it should be (for that engine RPM), it then causes an electrical signal to be sent to the KEBC actuator motor, and this motor then revolves a jackscrew that is attached to the one end of a lever. The other end of that lever then is then pressed against the driving pulley center bushing. This pressure against the bushing prevents the clutch from expanding (as it normally would if you were accelerating) and that causes the effective ratio of the clutch to remain in a low gear position, thus forcing the wheels to turn the engine, instead of the other way around.

The KEBC is not really a very troublesome gadget, but it does depend upon correct belt tension settings and it is designed to operate properly only with the standard clutch springs. The troubles begin when something is either out of whack, or the clutch springs have been replaced with non-standard ones. If the springs have been modified, then only God (or Nyroc) knows how to get the KEBC to operate correctly.

A word of caution...NEVER, NEVER, remove the belt cover without first turning OFF the ignition switch, because if you do that then the KEBC actuator motor (which is a computer-counted pulse-type servomotor) will begin to revolve and it will quickly spin itself to the extreme end of its travel. You may then find it quite difficult, (if not impossible), to get it back to the exact and correct setting after that happens, so don't do it! I make it a point to unplug the KEBC actuator motor immediately after I take off the belt cover.

Good luck.

(Wheeuw!) I hope that you got all that.

 

bigwave, after reading your post it seems that your braking system is working just as it is supposed to . the engine breaking is one of the best in the system and giving it gas to re engage the break is how it works. when i go down hills i gave it some throttle to get down ( engaging the engine break instead of the foot break) i found that it was the best way to have better control over the bike,a lot better then coasting and using the foot and hand break. but never had a problem with it not holding untill the engine rivs dropped off.it was a process on long twisty accents of re engaging the engine break and trying to hold it there by feathering the throttle. lots of practise that was covered by the better then average brakes to make up for the lack of attention to the process in hand. i have a attention disorder when driving the kawi i allways think about climbing the next hill or out running the honda's on the next long stretch. if it looks like its not normal , bogtrotter has it all covered on what to look for.

 

Thanks for the replys everyone.

Hay Bogtrotter, I did get that and I do understand everything you talked about. And I do believe the problem started after replaceing my belt about a year ago and the key did get turned on with the cover off and the tensioner having to where to go (still hooked up). Now, any ideas on how or where to start to reset the darn thing, there has to be a way, I just need to find it.

 

Bigwave, Here is Nyroc's website address. Here you can get much good information about your quad. Nyroc is definitely the man:

http://atv.dnsalias.com/forum.cgi

Go there, log on (and become a member, no charge) then go to the tech tips section and there you will see the various well-explained and illustrated technical tips, one of which will tell you how to reset the KEBC motor back to its correct position. That is the boss ATV website of all websites. If you still have questions, ask them in that forum and one of the moderators will give you an answer.

The short answer (and I am guessing at this one and have never done it myself, so check it out first ) may be to remove the belt cover with the ignition turned off, then reverse the two wires to the KEBC actuator motor (hooking it up backwards), then turn it on at the ignition switch and let the actuator motor spool itself up back (to its fully retracted position), then turn it off at the ignition switch again and then re-connect the actuator wires properly, and then replace the belt cover. Then turn on the ignition switch and let the computer reset the actuator position (with the engine running). It makes sense, but I dunno if it will work this way. Let me know if this, or some other fix, works for you... by PM if you can. Thanks and good luck.

( I still think the belt deflection may also be off its correct adjustment, by the way.)

 

I just posted a simular problem I am having with my BF750, the only difference I see is I had rpms and the engine was braking then out of nowhere I am freewheeling into disaster!!!