hey all,

figured i would share my newbie experience on the MCM and provide the steps a I took as well as the seat of the pants results. I did what seems to be a short cut version based on some videos i saw (did not remove the cams) and did not do the steps to modify or disable the KACR. I will apologize for the longwindedness now

After doing the MCM i put in the N1TC needle with the clip on the top notch (i had been running the stock needle, shimmed). I have to say i was a little nervous, I was having a hard time moving the sprockets, especially on the intake side- I thought I lost count of the teeth a few times and worried that Ii had totally messed up. I had made some additional marks with my sharpie marker on the cams to try to help but quickly smudged them away. I was initially confused as to what i was actually adjusting since it seemed that simply moving the sprockets would have no impact on the cams- but from what i understand, the small adjustment you need to do to the cams after adjusting the sprockets is what we are after with this mod?

after removing the cam cover and tensioner, my process was as follows:

1. put exhaust cam to TDC, marking the cam with lines for TDC.
2. removed bottom bolt, rotate, remove top bolt.
3. remove sprocket, hold chain tension, rotate 2 teeth, put back on.
4. slightly adjust cam to line back up with the new intake hole on the sprocket, bolt back on the top and then bottom cam bolt.
5. put intake came to TDC, mark the cam with lines for TDC.
6. removed bottom bolt, rotate, remove top bolt.
7. remove sprocket, hold chain tension, rotate 2 teeth, put back on.
8. slightly adjust cam to line back up with the exhuast hole on the sprocket, bolt back on the top and then bottom cam bolt.
9. put tensioner back in & button her back up.

once i had everything back together, the bike started up nice and easy. choked for maybe 5 seconds then settled right into a nice idle. Seemed a little louder than before and smelled richer but that makes sense with the new needle. i have my a/f screw at 2 turns out and needed to adjust the idle screw down a bit to sit @ 1300-1400 rpm idle. Throttle response was extra snappy and felt a noticeable improvement in low and mid range RPM, especially 4-6k- it felt similar to the stock power curve just with a lot more power overall! i was half expecting to pop wheelies with just throttle but that did not happen (i did get it up fairly easy from a 5 mph roll though). Power seems like it may be down a little in the high RPMs, doesn't seem as eager to rip to 10k RPM. All in all, its definitely an improvement and I'm very happy with it. I can't wait to get into some trails with this and feel the lower RPM power instead of having to really wind it out.

with all that being said, I'm kind of curious of how I would really tell if I had horribly messed up? On both cams we are moving the top bolt to the opposite hole (exhaust to intake, intake to exhaust) so had i moved more or less an 2 teeth, i would have to compensate by moving the cam more or less in order to line up with the new holes. Since its running good, I'm hopeful that i did not mess up- just curious if there would be obvious signs if i did. More or less asking for the "margin of error" with this mod. Lastly, any ill effects of NOT disabling the KACR? I'm not understanding why this has to be done with the MCM mod, and the bike started well both hot and cold throughout the day.

apologies again for the long post, but i figured this might serve helpful for some other folks and i wanted to share my experience.

 

Personally I disabled the compression release because it just isn't needed. Why blow half the fuel charge out the exhaust when trying to start. It may have been needed on the kick start 250/300, but just not needed with e-start. As for MCM it is based on Marcelino's experience.

 

You did not set and maintain TDC on the combustion stroke while doing the work ?

With both cams bolted onto the correct set of holes, there is not much else to go wrong except screwing up the gear reposition on the chain - IIRC, the gears are rotated toward each other when doing the repositioning..

Your KACR should now be far "out of spec" and you should not have hot start capability..The KACR should be keeping the exhaust valve open way too long into the combustion cycle for proper hot starting..

 

Perhaps your KACR is nonfunctional.. The hot start issue is a proven problem with MCM+unmodified KACR..

The loss of power above 6.5k - from your previous mod combo - should only be a fraction of a hp. The increases elsewhere more than makes up for this, right ? .

 

as far as the TDC on the combusion stroke, i believe i did. I might be saying the wrong thing, i certainly had it at TDC when moving the gears and adjusting the cam, but i turned the motor over to get to the different bolts. I believe the gears are moved away from each other when rotating (clockwise on the exhaust and counter clockwise on the intake)

interesting on the KACR. i rode for about 20 minutes. killed it, then went back out maybe 2 hours later for about 45 minutes. not a "hot" start, but it fired right up with no choke. i'm pretty sure once i came back home i killed it and started again but i will try out the hot start scenario, i don't want to get stuck in the woods down the road. worst case i'll pop the head cover off again and pull that spring off- can that be done while its still on the cam or does it need to be removed?

 

now that you say that about the KACR, I didn't take a close look at it, my father was messing with it though- and it was very "floppy". maybe the spring was already out!

yes, i much prefer the current set up with the bumps in the lower ranges.

 

Yes, I misspoke.. The overall result of the MCM is that the CAMS are moved slightly toward each other.. The direction of the gear repositioning is that the gears move away from each other...


You'll certainly need to test hot starting very carefully.

 

still not having any issues with a hot start. i rode for about 30 minutes, shut down for a few minutes, started right back up. rode for another 15, shut down same thing. Perhaps the KACR is not functional after all...

 

Well outstanding!

Perhaps we've already talked about this - I can't remember .. With that short N1TC needle@1N(top notch), you must use the stock slide spring on an undrilled slide lift hole/port. Both DJ needles must do this as well but it is paramount when using the N1TC. If your lift port is drilled, JB weld it shut and carefully redrill with a 3/32 bit. If spring is unknown, order a new one.. The results are worth far more than the hassle/cost...

If I am only just now giving you this guidance, I sincerely apologize..

 

no worries- i am using the stock slide spring and i did not drill the lift port. when i first messed with the carb jetting/shimming the stock needle i chose not to mess with the spring and port. didn't seem worth the risks.