Silly question. If I try MCM with 300r cams, how can I make sure valve clear the piston? How can I measure the gap?

 

The classic method is to place plasticine (kids' 'modeling clay', i.e. non-ceramic) in the valve reliefs of the piston, put the head back on and carefully turn the motor over; take the head off again and results will be visible.

 

Thanks! I was hoping to find the trick which will allow to do that without removing cylinder head.

 

tsc: I empathize; I've had numerous hopes of that nature myself...Merry Christmas! {;^)

 

Any update on what we officially agree is best on these bikes yet. 300cc efi looking to upgrade to either 331 or 351 trying to decide if I want a Japanese ecu and if 02 and bigger injectors are better as well ar marc cam mod. Been waiting 3 years for a solid agreement from the community. I thought by now one of the tracker guys from thialand or someone here would get it sorted traded my old 09 klx carb for a 2022 and although it seems to do just fine. And a little better than my old carb guy especially in the higher elevations I would like just a bit more punch.

 

I think you're in the wrong thread for that. There are a couple threads dealing with the EFI bikes now. Klxster has one going and others have posted some stuff.

 

Cant see any of your photo's
I'm mid mod and would like to see some guidance please

 

If you are writing to me, I just checked the link in my signature and it still works to get to the Google document that is shared with anyone using the link.

 

I did it to my 06klx250 a couple years ago and was very pleased with the results. Less high end power but significant low end improvements. With a 52t sprocket in the rear it climbs like a goat now. It will chug up some rediculously steep hills at low RPMs that would have stalled it before the mod. I sometimes need to push with me feet to keep it from stalling but it still impresses me how it just keeps on chugging along.
However, Ive got around 40,000km on it now, have to guess because my speedo got stuck at 30,000km, and now it has started to knock quite loudly, especially at low rmp. That may be because the noise at higher RPMs drown it out though. Ive been told by my local dealer that 40,000km is about the limit of that engine before a rebuild is needed but I'm wondering if the cam mod is partly to blame for all the noise.
Any thoughts?

 

Get a mechainc's stethoscope from Harbor Freight or similar, like $10. Then listen around the engine with the probe to find out where the noise is loudest. If it's in the head it could be cams, but I doubt it. If it is the bottom end you need new bearings and probably rod kit. The MCM cam timing change will not cause any of what you are experiencing. It simply changes when the cams open and close, which is what alters the performance. No additional wear.

Plus there is a thread in the ADVrider forum where a rider in Thailand (I think) has done over 100,000 miles on a KLX with a 351 kit on it. I know he did some work over the miles, but it still did the job beyond the 100,000.