So you want to know what the inside of the motor looks like?

[safiri]

I swapped out transmissions on my formerly MXC, now EXC, KTM RFS. Wanted the wide-ratio, lower first gear - higher sixth gear versus the MXC close-ratio 6 speed.

Figure most brands are going to look similar.

http://home.everestkc.net/malsin/Motorc ... roject.htm

[MoRidin]

That chain guide is a GREAT change.

Mike I gotta say that motor looks CLEAN. Very little scarring on any of the moving parts. This would be a great thread to post for the Rotella doubters as this bike consumed exclusively Rotella for the fist 5-6 years.

Awesome writeup Mike. So, how do you like the change?

[safiri]

I thought the inside looked great as well. I didn't separate the head (actually, lower half of the head) from the cylinder so I don't know what the combustion chamber, valves, etc. look like. Looking up the bottom of the cylinder I didn't see anything of note. Not much to see, however. Despite what the pictures lead you to believe, the inside of the engine is actually quite simple in design. KISS.

Since getting the bike a year ago, I have run either Mobil 1 10-50 or Castrol Synthetic 5-50 from the auto parts store.

Of note:
- The lower cam chain guide is a good upgrade.
- There is a new cam gear (top, on cam) that gets rid of that little silver bolt. First, it is $45 or so. Second, you have to disassemble the cam shaft (pull off one of the roller bearings and press it back on, which at that point replace it) to get to the gear. Some of those little silver bolts have failed and dropped down into the engine. The lower guide should keep this from happening. With all of that in mind, I used a spring punch to jimmy the threads of the bolt that protruded from the lock (not nyloc) nut.
- I upgraded the shift spring lock to the newer one ($10) that gets rid of a little ball bearing and replaces it with a simple sleeve.

I have about 10 miles of road riding on the bike since put together. I am still running 13/52 gearing, which is what it had as an MXC. Thus, wheelies are REALLY easy in first gear, which is much lower than it was. I will bump up to 14/52 when I change out (I already have a 52, else I would go 14/50). The higher sixth is really nice at highway speeds. I just got back from a short run on the interstate at 65 mph. The bike purrs along, not high rpm at all. The 400 will still accelerate when given throttle at that speed, although fifth gear would be preferable for that. I think I am going to really like the lower first when I need it, which isn't often. Otherwise, I will notice having to shift into second to ride what I used to ride in first.

[MoRidin]

Mike:

I will look in the garage tonight. There is a chance I have the OEM 50 as I pulled that off quickly for a 52. If I do, I will PM you and send it your way.

[Hank Moody]

Wow! Great write up and photos!

So I thought re-greasing the head bearings, replacing the handlebars and installing a steering damper was a big project! I'm still waiting on the OEM radiator fan, apparently still on back order from BMW/Husqvarna USA

Mike this should make those hard climbs much more manageable with the lower gearing. Then you will be able to run away on the highway when we head back to the barn.

[safiri]

Wow! Great write up and photos!

Thanks. The job looks a lot more complex than it is. Then again, every time I touch your bike I screw it up ... Damn Swedish things! (BTW, I'm 50% Swedish!)

So I thought re-greasing the head bearings, replacing the handlebars and installing a steering damper was a big project! I'm still waiting on the OEM radiator fan, apparently still on back order from BMW/Husqvarna USA

You will really like having the damper. REALLY LIKE! (Yes, I am saying that loudly.)

Mike this should make those hard climbs much more manageable with the lower gearing. Then you will be able to run away on the highway when we head back to the barn.

That is what I hope ... especially the former. The latter might be pushing it on a 400, but cruising I will be able to drop the RPMs down and be nicer to the engine and get better mileage.

I will look in the garage tonight. There is a chance I have the OEM 50 as I pulled that off quickly for a 52. If I do, I will PM you and send it your way.

That would be appreciated, but I certainly understand if you can't find a sprocket that you removed 4 or 5 years ago!