so finaly the bike is ok,

i did the mcm only for the inlet cam....

at first i have the stock timing but with about 1/4 touth advance at both inlet and exhaust (2-3 deggress), than i did the mcm only for the inlet. This means that now i have 2-3 degrees advance at the exhaust and 5-6 degrees retard the inlet.

the bike realy goes better now. I use to have it 300cc (now is 250) but it seems to me that it goes like 300 after the mcm at the inlet... I believe also that the reprofiled cams are realy giving more power with the mcm..... Thanks Marcelino!!!!!!!

 

Same thing some of my seventh graders think too...

They know it all, their other teachers and I know nothing.

 

i made also an adaptor for O2 sensor at the exhaust, in order to set the AFR properly. right now i have dynojet stage 2 for klx300 with the needle at pin 3, pilot screw 2turns back and oem 132 main jet.

 

I don't quite understand what you did here. Is the MCM not advancing both cams in the 8-10 degree range? If so, how are you advanced on the exh. only 2-3 degrees, but retarded on the intake 5-6?

 

you can make the timing slightly retard at both cams. you can do this by not putting the inlet mark exactly align with the top of the head but put it slightly advanced (just 1/4 of a touth). If you do this you will have both inlet and exhaust cam 2-3 degrees retarded. with MCM you do 8-9 degrees avance to the inlet and 8-9 degrees retard to the exhasut. I did only the inlet so after the mcm to the inlet i am : -2 degrees retard +9 advance = +7 advance. the exhaust staid at -2 degrees retarded from the first slightly retarding timing.

i did this because i couldnt do the mcm to the exhaust cam as i had problems with piston - exhaust valve clearence.

 

So advise me here Mark. The ACR uses the spring to release compression? When the revs pick up the shoes are centrifugally displaced to the outer position. So the wire lock is used to lock the shoes out in a stretched spring position? ( I have 101's anyway but chucked my spring)

 

I'm feeling the need to remind readers that the MCM advances the intake cam and retards the exhaust cam.

 

yes that is correct i ment the opposit. i ll corect my post

its more easy doing it than describe it...

i sould have taken pictures...

 

Yes, the spring helps pull the shoes (counterweights) in so that the decompression mechanism hits the valve shim cap, opening the valve.

The only reason I used the wire lock out was just to stop any movement rather than let the counterweights move at all. Consider it a sort of security measure - two less moving parts.

The compression release is a hold over from the kick start KLX250/300 and with the electric start is proving to be unneeded. As I said, research shows neither the CRF250L nor the WR250X/R use a compression release and the Supersherpa doesn't use one either. Seems the starter has no problem spinning the engine over sans compression release.

If I do anything with the top end I'll probably have the mechanism pressed out, cutting a bit of rotating weight off the cam.

 

klx678, you can just drift the ACR off. Properly support the cam, get a small sledge hammer and an appropriate, heavy, drift.