I bought a 2006 KLX250 from a guy who was second owner and he said the 1st owner had modded it.

I know it has to have most of the stuff done to it listed here since it starts and runs fantastic and I have no issues with power delivery etc.

Is there an easy way to tell if the MCM has been done?

It has obviously been rejetted. Open airbox top. Full exhaust (too loud for me but damn!!!), Manual cam chain tensioner.

Really wondering about the MCM and decompression device removal.

What would I look for to see if that has been done?

Is it obvious?

Love this bike!!!

 

Easiest would be to check if the KACR has been disabled, then look and see if both cams are out of alignment. Read over one of the posts on completeing the MCM and you'll find pics that will help *grin

 

So If I pull Valve Cover it should be fairly obvious?

I need to check clearances anyways since I don't have a great history on the bike.

 

yes... viewing the alignment marks on the cams will tell you for sure. I don't have the instructions handy, but you should be able to search and get the document including good pictures. You'll want to know if it has been done in case you have to pull the cams to swap out a shim. If it has been done and you pull the cams, you'll need to know how to align them correctly on reassembly. If it hasn't been done... you might consider doing it while you are in there...

 

Assuming the carb, etc, are in good working order with new fuel in the tank - If the bike starts instantly, it likely has the MCM. This is kinda subjective. But MCM bikes - especially when warm - will fire before you can push and release the button..

If it doesn't fire up like that, it could still have the MCM.. But instant firing is a hallmark of MCM..

 

OK, found it.. here is the doc I used and it has a couple of good pictures..

https://docs.google.com/document/d/1...m3gkMeNUU/edit

 

Intake cam will be in exhaust holes on cam sprocket and exhaust will be in intake holes.

 

Yep and off 2T as in pictures. Otherwise I don't think there is any other absolute proof to be positive the change has been made.

 

I did the MCM and bike runs great. If you notice, I scribed a faint line on the drive side of my cams before I did the MCM so I could clearly visualize the relative change in cam angular position. The lines used to be parallel to the valve cover gasket surface but now the cams can be seen to have rotated toward each other. TDC found with a plastic straw on piston and moving bike in 6th gear until I find it with both cams on base circle. Bike power has softened slightly in recent rides. Probably just my *** getting fatter. Valve clearance probably too tight. Plan to set new clearance near the max spec. Still have to look at the specs and calculate shims needed. Interestingly the spark plug shows little evidence of rich fuelling.
Perhaps there is room for improvement but getting 70 mpg if I don't hammer it is nice.

Edit: Just looked at the specs and the cam drive side is too loose, other side is still in spec but on the tight side. My guess is that the drive side cam bearing surfaces are wearing faster than the valve clearance can tighten up from wear. I wonder if a MCT set slightly loose would remedy that. Thinking about measuring the cam bearing clearances to see if anything is amiss. Should be between .001 and .006 inches. Now to find some plastigage in that range.