kx65 pipe vs a kx85 pipe, which would be better for me?

mark20

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well, im thinking of buying a used dirt bike pipe and welding it on to a 66cc 2 stroke bike.
however, im stumped between 2 pipes, the kx 65 pipe and the kx85 pipe. (only ones available)
i figured the more pipe the better, (i like to have a vertical set up, not a belly down set up)

i will be doing some basic port work, and messing with the squish gap. i might adapt my 22mm pz carb on there if i have too.


the engine is currently stock with the head sanded down roughly .010, it will have a 36t sprocket as well.


so, i need some opinions here! (and i would like to stick to these pipes if i can help it, as there basically the perfect shape for my bike)
 
I have never used a KX65 pipe but I have used many others. As popular as the KX85 pipe is, the KX65 is probably better for most builds honestly.

Going from a KX85 to a RM80(much smaller) on the same bike cost my ported triple40 2-3mph but had much better mid range. Both were same exact diameter and similar length stringer with the kx85 stinger being 2" longer to help the low end. RM80 would be much more fun to commute on even though it was a tiny bit slower up top since it didn't rev as high.

Keep in mind Kawasaki uses the KX85 pipe for both their 85cc AND 100cc motors so it is quite a bit bigger than other 80cc pipes. YZ85 probably comes the closest.
 
I'm using a KX65 pipe that i cut up, reconfigured, then took its first divergent cone and replaced it with the first divergent cone off of
a SBP expansion chamber lol https://motoredbikes.com/threads/stinger-length.54364/page-33
Sounds weird i know, i just wanted to try the longer thinner first cone off of the SBP pipe, someone said better torque :unsure:

Anyway, i am going to get another KX65 pipe, cut it up, reconfigure it but use the whole thing this next time around to see what the changes are going to be.

KX65 in my opinion.

 
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Looks the the kx65 pipe is probably better for most things other than top speed. Looks like thats the one for me
 
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