16t sprocket

[PowerFiend]

Slow600,
Sounds as you have your K5 running good. You posted else where that you had problems with the 450's hanging on the straights (quick search did not find it). If you are now looking for more gear & spinning the tire you found the solution? I read you switched to the PC2 & the VF2 anything else??

When I was running my 97 CR500 in SM trim with a tired stock topend and only a VF2 and PC pipe, I never had any problems with 450's on the straights. The hardest part of running the big smoker was corner speed, if he was getting past on the straights it was probably due to poor drive out of the corners.

[Polar-Bus]

Slow600,
Sounds as you have your K5 running good. You posted else where that you had problems with the 450's hanging on the straights (quick search did not find it). If you are now looking for more gear & spinning the tire you found the solution? I read you switched to the PC2 & the VF2 anything else??

When I was running my 97 CR500 in SM trim with a tired stock topend and only a VF2 and PC pipe, I never had any problems with 450's on the straights. The hardest part of running the big smoker was corner speed, if he was getting past on the straights it was probably due to poor drive out of the corners.

It's the engine braking that the big 4 strokes have. I get my butt handed to me out on the ice oval, for this exact reason. Not from being out accelerated, but from being "out-braked" I also have a YZ450F that I set up this winter out on the ice, and wow, you can stick a 450F DEEP entering a corner (vs. my KX500)

[DoldGuy]

I don't want to Hijack this thread, but has anyone used a compression release (in the head / not like Accu setup). We used these in the old days (Flat Tracking) & they really helped the bike setup for the turn by allowing the rear end to step out in a controlled manner allowing you to run it in much deeper. It was very similar to the current 4 strokes (250F/450F) but not as much as the Yamaha TT500 when they came out. Just my thoughts.

[kaw rider]

I have a picture of one in the head. It would be alot easyer if stewart made a billet head and then machine the dome for it. Like this one is. Then you would have to machine your cylinder for the decompression valve.

[jfabmotorsports.com]

I don't want to Hijack this thread, but has anyone used a compression release (in the head / not like Accu setup). We used these in the old days (Flat Tracking) & they really helped the bike setup for the turn by allowing the rear end to step out in a controlled manner allowing you to run it in much deeper. It was very similar to the current 4 strokes (250F/450F) but not as much as the Yamaha TT500 when they came out. Just my thoughts.

What causes engine braking on a 4 stroke?
Why do 2 strokes and diesels not have it?

[Motorrad]

how would a compression release help engine braking into a corner??  Wouldn't this hurt it further...   You lost me on this one...

[jfabmotorsports.com]

how would a compression release help engine braking into a corner??  Wouldn't this hurt it further...   You lost me on this one...

Thats where I was heading. If you had a 2 inch hole in the head it would release a lot of compression and not slow the bike down. I would like the theory explained to me though, please.

[DoldGuy]

I will TRY to explain. Imagine going down a straight with an upcoming some what tight left hander, your in fourth or fifth gear with the motor tapped, what do you do, you grab a handful of brakes and MAYBE down shift a gear if it does not cause too much rear wheel hop. This is where the comp release comes into play, you use the downshift (or 2) to come in hot & let the motors gearbox be the Controlled engine braking (which feels much like a current F four stroke) and with a turn left, then right, the rearend steps out smoothly & controlled. If anyone has tried to go fast on an oval before will tell you, you have to be aggresive & smooth to have good lap times. Next time you go riding, try downshifting 2 gears with the clutch out & see how much engine braking is actually in a 2 stroke, it's just not smooth like a 4 stroke. I hope this gives some what of an explanation.

[azracer19]

As far as compression release operation, When I first learned to ride, many years ago my Dad would take me to Bay.mar it was a TT track i was tought to hold the throttle open and pull the compression release going into the turn release it back onto the straright...  the entire time holding the throttle open this was on a 100 cc bike. it would be dangerous IMO to use this method on a 500. I was kinda like drifting thru corners I suppose

[slow600]

the kx would lose in a straight line race to my 450 before. now that it got some love thanks to good ole stewart its a different animal. all the new-found power almost caused me to biff twice due to excessive tire spin coming out of a corner. around a course my 450 is definatly quicker due to several factors, but straight section is absolutly no contest. its almost humorous how fast it pulls away, the 450 is not stock at all either. sigh.....i hope i dont get too many tickets this summer. 

[alward25]

i thought sidewinder made down to a 38

That would be funny to have a rear sprocket almost the same size front sprocket.

[Polar-Bus]

What causes engine braking on a 4 stroke?
Why do 2 strokes and diesels not have it?

A 4 stroke engine has a much longer and complete compression stroke vs a piston port type 2 stroke. Also the fact that the engine has to turn over 4 times vs. 2 times for every power stroke also causes a lot of stored inertia that takes longer to decellerate. It took me a LONG time to acclimate to hitting jumps with my YZF vs. my 2 stroke. If you slightly "chop" the throttle off the face of a jump with a 4 stroke, the engine braking causes your front end to dip, and then you will most likely be taking a dirt nap..    

This is my crude comparasin of 2s vs. 4s, i'm sure there is someone here who can explain the details far more precise than me..

[oic0]

As for diesels, this page explains how a jake brake works and why they don't have engine breaking to begin with. http://www.jakebrake.com/products/how-the-jake-brake-works.php

I fail to see how a standard four stroke is different than a diesel though? Maybe both of them have big ol pumping losses, just a diesel is usually pulling a much larger weight so it isn't enough and they need the extra hit from a jake brake?

[jfabmotorsports.com]

I will TRY to explain. Imagine going down a straight with an upcoming some what tight left hander, your in fourth or fifth gear with the motor tapped, what do you do, you grab a handful of brakes and MAYBE down shift a gear if it does not cause too much rear wheel hop. This is where the comp release comes into play, you use the downshift (or 2) to come in hot & let the motors gearbox be the Controlled engine braking (which feels much like a current F four stroke) and with a turn left, then right, the rearend steps out smoothly & controlled. If anyone has tried to go fast on an oval before will tell you, you have to be aggresive & smooth to have good lap times. Next time you go riding, try downshifting 2 gears with the clutch out & see how much engine braking is actually in a 2 stroke, it's just not smooth like a 4 stroke. I hope this gives some what of an explanation.

Thats an awsome explination of why you would want engine braking. Now, how is a compression release going to slow the engine down? Were the slipper clutches designed to get rid of the engine braking that 4 stocks have so that you could use the rear brake with more controle?

[slow600]

well i got the traction issue under control this morning. i swear the distanzia's feel d**n near like slicks. every kx owner should get to experience a power wheelie while still coming out of a turn. my 16t front is not here yet, but i almost decided im not gonna use it. i cant bring myself to get rid of the case saver. im waiting on a completion of a pmp 40 tooth rear. hopefully this will keep me in the "meat" of the power for longer.