Worst thing I ran into was getting the sprockets on the right teeth - not much danger since the marks are quite clearly off when wrong - but I'd just either be a tooth off one way or the other or go the wrong way. No biggie, but goofy on my part.

The only other "regret" was not being able to foresee that the KACR is unnecessary. If I had I'd have gotten it pressed out. I didn't have whatever to do it without any concern for damage, so I didn't do it.

Key point for lesser experienced mechanical types to eliminating that "disastrous" factor is to double/triple/quadruple check work and then still spin the engine over slowly with a socket and ratchet/breaker bar on the crank bolt to make sure it will turn over without any valve interference.

A rider doesn't need to be a master mechanic, but it does take good mechanical sense relating to the process. They don't really need to "know why" but do need to "know how". You don't need to understand internal combustion to change a spark plug or exact valve/piston clearance to shim for proper valve clearance, don't even need to know the science of fasteners to torque a bolt/nut - just need to be able to do the wrenching correctly.

One can have a master's degree in mechanical engineering, but if one strip one's drain plug one is still hosed. Gotta be able to do.

 

I think I can help a bit. No, there is no need to change from checking valves at TDC compression. I'm sure you realize the whole TDCC (Top Dead Center Compression) is to assure both cams are off the valve caps, max clearance will definitely always be at TDCC as well as a fair amount of rotation either way, but TDCC is absolute. The cam re-timing will not alter that fact. Clearance could be checked on intake at other positions as can exhaust, but on a single and most twins it is far simpler to use TDCC.

Key points will always be crank at TDCC and cams rotated to proper positioning with front run of cam drive taut, stock or MCM. I'd put the chain on, set cams in place and rotate intake back by hand the small amount to take out play, then look at the marking.

As I've said, I bounced around with the chain teeth, but nothing of any issue, the markings and positions are clear and obvious. If you are off a tooth or whatever it is quite clear. For me it was just the fumbling around of the cams fitting to teeth then re-seating in the head that caused the bit of issue with teeth - going the wrong way didn't help for speed of work. My other bike is shim over bucket so I never bothered with cams out and previous to that they were single overhead cam and push rod (MotoGuzzi) - easier to set up.

After the fact, doing the mod a second time would be a breeze.

I recommend since you are shimming, loosen the cam bolts while in the engine, then do the actual removal and shifting of the sprockets on the bench - no way to drop bolts in bottom end. In addition, suspend the chain with a screw driver so as to not drop it in the tower, not that it is a big deal, just some time getting the magnetic wand to pull it back up. There is no specific positioning on the chain, just the end relationship of cam timing/sprockets to the crank at TDCC. I remember someone was saying something about keeping the cam chain in exact position - it's an endless chain of identical links, no big deal.


Valve adjustment side story: On Gold Wings the manual had the valve adjustment (2 valves/cylinder) done in two rotations, one had a cylinder at TDC compression and two on either exhaust or intake stroke, adjust four valves (both on one cylinder, intake on one and exhaust on the other), then spin the crank to get the untouched cylinder on TDC compression, which put the other two in position to get the unadjusted valves done (both on last cylinder exhaust on one and intake on the other). Pretty crazy, but efficient. Standard in-line fours worked the same. At least most of the Hondas used screw adjusters and the shimmed engines didn't get valve check at set up. The V-4s were a pain in the butt, because they were difficult to access compared to the others.

First motorcycle I set up at the dealership was a 1982 standard Wing, so I got kind of a trial by fire. Previous to that all it had been was two strokes and a MotoGuzzi where you did left side TDCC, then right side TDCC. Since that time it's been a variety.

Best was doing the Nighthawk S - hydraulic valve adjusters, change oil!

 

It is done. Have yet to torque the cams in but the tensioner is in and my faint cam shaft marks look rotated as expected. Slightly adv on intake, slightly ret on Ex. My pic approximates the MCM thread pic. Darned bike shop doesn't carry shims so I had to order. Don't want to wait a week to ride my bike so I am throwing it back together and will install the shims I ordered in a couple of weeks. I do not think a few hundred more miles will burn a valve. I still have over 0.004" on my tightest exhaust valve. If anyone disagrees I'd like to hear about it. Pretty easy job. Only needed the manual for the specs. Thumpers are a lot easier than my V4 Honda on valve clearance. And the ACT is so easy to install compared to my V4 Honda. Gonna order me a Krieger MCT just because and my last thing is a new back tire. Intend to install at home with a home grown tubeless conversion. Going tubeless was the best improvement I ever made to my mountainbikes. Hope it is nice on a moto too.
First ride impressions: The cam chain is louder. Result of the work or just noticing it? I think it is louder. It was not this loud when I had the lid and snorkel in place. Maybe the ACCT needs to settle in. Krieger will get some money from me soon. The front brake is gonna take some getting used to with Galfer semi metallic pads and brake line. Faster, easier stopping than before and the pads aren't even broke in.
The MCM mod kicks ***. I guess I got it all right because there are no bad mechanical sounds from my engine up to 8krpm, intake noise is less obnoxious, and the front wheel levitates a bit easier with less rpm-clutch play needed. I think I need some time on soft dirt to get the feel for the balance point with softer landings when I go too far. Even without moving back in the seat I had the front off the pavement without trying to. Overall the MCM mod was pretty easy. I didn't even check my work afterwards. Just slapped it together and fired it up but did ease into the rpms bit by bit to make sure I didn't screw up, and I didn't. Will put in the new shims I ordered next week or so. Need to pop in the new larger DJ mains I received. She feels a bit more lean today. Will start small and work up to the largest. I raised my DJ needle to 4N/128 and lost a few mpg. Will be interesting to see how MCM affects economy. If I can stay off the throttle. If you have any curiosity about it, DO IT. The MCM that is. A very good and cheap HP booster. Now if I could lose 30lbs I would have a really fast bike.
Lost Part: Anybody know of a cheap way to replace the washer/gasket that the 3 valve cover bolts sit on? Somehow I lost one and can't find it in the garage. Maybe it fell in the engine?

 

OK.. so 128/4N.. I know your running an X3, so if you also have the airbox lid off, you are lean everywhere.. In fact, until you drop in at least a DJ136, you might actually get more performance by putting (just) the lid back on..

 

Stoppies and wheelies oh my. MCM is the bomb. I have DJ136,140, & 144 main jets to get rid of the lean fuel mix. Changing the needle position might be a little more time consuming. Will probably leave my needle at 4N and slap in the DJ140 main and see how it runs. Wish I new why the keihin pilot jet they sold me at the LBS looks different from the one in my carb. Could it be a DJ pilot on my bike? Between the front brake upgrade and power upgrade I got a whole new bike. Can't see why I would ever want to go with a DRZ400SM as the KLX250SF is smaller and lighter, like me, except I am not as lighter anymore. I am looking forward to throttle wheelies in 1st gear next week once the carb is sorted out. Thanks to Marcelino and everyone who helped me understand the mod. Piece of cake..

 

DJ doesn't make a pilot jet for the KLX250.. Just back out the fuel screw 3.5. to 4 turns until you get a 38 or 40.. 140/4N could get you that lovin feelin (of your bike doing a reverse cowgirl on ya in the middle of the street !) Also, with the 140, once you feel the WOT power from 7.5k on up, your addicted. You'll be making up reasons why you have to go ride.




I did a dyno pull with stock header + DGR and 140/5N - it went way too rich (a low of 10:1) from off idle to 6500 rpm (Here is the post - https://www.kawasakiforums.com/forum...-slipon-42907/),,, My local dyno tuner/dyno operator/shop owner says the notches are usually good for 1 full point of AFR - Point is that even though you'll love 140/4N, just know that you could be overfueling the midrange..

Also, because of its' design, I think your X3 might produce a little more HP than my DGR..

 

Pilot jets:
N424-25- (#38) Kawasaki part no 92064-1050
N424-25- (#40) Kawasaki part no 92064-1108

 

Uhh, 35hp out of the box, slight increase in weight

 

I have been a total thread hijacker. Sorry. Anyways, I may need to get a 400SM to taste and see if I like it more. I suppose the lighter weight of the SF would be better at trail riding. I generally stay on the street, so far. I saw a 2009 KX250 locally for 2900. Imagining that bike crossed with SF street legal parts, wheels, and brakes. 230 lbs. THAT is the supermoto I want. Hey, klxster, I slapped in a DJ 136(from 128 previously) at 4N still and opened the idle screw to 3.5 turns. Short ride in the hood and even more power is on tap. Exhaust sounds a little fuller. Had to dial up the idle speed a little. If the rain holds off I will get out for a longer spin including local interstate.
Test ride done: Fuel economy is down 15% but fun is up. More full throttle use does that too. No more lean surging from 55-75 mph. A lot more spunk in midrange. Bottom end rpm feel soft, 3-5krpm. Need to find the correct pilot jet.

 

Yep, I know snappster.. But 136/4N is a "No-No".. Your midrange AFR @ 4N with the 136 will be well into the 14's - maybe close to 15:1.. Your bike running 136/5N is the 4th chart down in green - https://www.kawasakiforums.com/forum...-system-42926/

136/5N, perhaps, would make a good setup for you (and me) in the summer heat..

Your "holy grail" could be 140/4N - Below is my DGR chart using 140/5N , this is tantamount to your bike.. Imagine the midrange AFR on this chart(about 5.5k to about 7.5k) being 1 point higher with 4N, PERFECT! - Ignore the fat low end as that was an overly rich fuel screw setting on the #40 pilot