Did you notice that type of wear pattern on the piston/sleeve during early break in? Mike told me to hit it for two or three more tanks at 240F on the track then shoot for 280F. Ron C. also told me they start the MSR spring at 9.2mm and toss it out by 10mm because it looses it's "memory" and your clutch setting will not be consistent.

Like mugen drew stated I would go with what Mike Swaugers advice since he has loged a lot of time on these engines and you are getting your info from him first hand. I'm sure other pros have different methods but then you don't have them here to give advice on this particular motor.

The the clutch advice they gave you is pretty good from when I have tried it.

Not at all....
I try to for already 20 years now. but it's still nothing......

your in the ninja thread, what do you think people will recommend? lol

I'm definitely not going to doubt ANYTHING RonC. stated. This weekends setting started at 9.5 with a uncollapsed spring, new drilled flyweights, 3racing lite weight STEEL clutch bell, new yellow and used clutch spring seat and nut. It bogged out of the corner, L.S.N. setting was checked but there was no gain. Adjusted nut to 9.8mm, now we got something,10mm better, 10.2 set on kill. I had a decision to make at this point because the car started shaking the tires out of a large 180 that leads on to the front straight, back off the nut or go down on the spur. Went down on the spur to a 49 and it was magic. Ran this set-up for 5 practice tanks, 4 qual's and a 20 minute main. From start to finish I noticed no difference and the lap times reflect this. And the little devil that pop's up on your left shoulder would not shut up...

CD, yeah I have noticed using a digital ball mic that the manufactures have started doing different things with sleeve taper to hopefully achieve longer engine life in the "sweet spot". The original ds had a visible step 2mm under the bottom of the port openings. As far as what I saw with the Ninja I gave it a couple of more tanks on the bench. Track running I did a tank at 240,250 and 260. Still plenty of smoke down the long straight so we start turning the needle..."when in doubt, lean it out".

all ok here
this weekend firts time a race after the Winternats now let's hope the wheater will be ok.
need NITRO smell

Well, another weekend of racing. The MR12 just passed the 1 gallong mark and it is finaly broke in. Still has a pinch at the top, but doesn't squeek anymore. the engine has A LOT of top end, but the bottom end was a little sluggish at first, till I found the right combination of clutch and gear. The only incident the engine had all weekend is at the beginning of the 4th qualifier. My pit man couldn't get the engine started and flooded it to the point it hydrolocked. (all due to a dead glow-starter)

The engine ran very well all during the main, but the car on the other hand was a bag of (you know what), thanks to a hit 2 min in to the rear arm. I drove the car with a broke rear arm for 18 more min and still ended up taking home the 1st place trophy for the main.

If anybody has any doughts about this engine, don't. It holds a tune and has plenty of power, even with a fuel line leak I found after I got home during the tear-down.

I'm not sure if Mike and Ron are drilling their shoes- wouldn't that be cause for having to crank down on the nut to get the same punch out of the clutch? If the shoes are lighter the engine has to be higher in the powerband to keep them on the steel plate right?? The lighter shoes will slide out quicker, but not as hard as a non-drilled shoe.

I may be hosed in my theory.... it's awful late here on the east coast

Don't light shoes move out fast but hit soft/ Heavy shoes move out slower but hit harder?? (both assuming the same spring compression).

I need some edumacation on that

lighter shoes engage at higher rpm.

with same spin tension the lighter shoes would hit harder, because more force is required to 'spit them out'.

Im no rocket surgeon, but the force will be the same, its the engines powerband that you want to tune for. lighter shoes, later engagement. heavy shoes, earlier engagement.

Actually, I drive 1 league higher than You Michel.....

With the mugen clutch, with 4 shoes in between the pins, it all comes down to centrifugal forces.... with the serpent type of clutches, it's a bit different.... (just to make people a bit more confused... )

But as we are talking mugen now, lighter shoes will engage later, but also with less force....
If you are having mid power problems, lighter shoes might do the job, because the clutch might help (due to some slip) to keep the rev's of the engine up...
Heavier shoes, with a harder spring setting might let the engine bog down a bit.....

yes this is what i meant! thanks randay.

i just couldnt think of how to say it lol...