I always followed the "slow break in" procedure but used the following process on the last couple of engines I built with impressive results

Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

 

10-4, I remember reading that a few years ago... I will put it to use on the 331, Thanks!

 

I also use Motomans' break-in procedure. The problem is that his his instructions for the "street break-in"are vague. You have to read his Dyno break-in procedure and duplicate THAT on the street. Preferably, late at night on a lonely road.

Main thing is, it must be done immediately. You fire it up for the first time, let it idle until fully warmed up, then immediately perform the proper Motoman break-in procedure.. 20 minutes later, your DONE !

 

So here is the knowledge, condensed for a Motoman "street" break-in - with a "twist" or two for the KLX250.

1. With all systems checked, a 4 mile stretch of empty roadway nearby, and cool weather, give the engine its' first startup - start only to idle. Check for any problems while the engine is at idle, warming up.

2. (Use 4th gear for the break-in procedure.) Applying 1/2 throttle and a cap of 6000 rpm, run thru gears to 6000 rpm in 4th - Allow bike to decel with closed throttle, without using the brakes, to 4000 rpm. Apply 1/2 throttle to accel back to 6000 rpm, then decel back to 4000 rpm. Do this one more time. There should be three accels and decels total.

3. Immediately repeat this process 3 more times but using 3/4 throttle accels to 8000 rpm ( and decels to 4000 rpm)

4. Immediately perform 3 full throttle accels to 10,000 rpm, but with decels to 3000 rpm..

You are done ! Now you can run it any way you want to..

I share this with you only because you are going to do this break-in with the DJ148 lidless CVK setup - which I know will be proper fueling for wide-open throttle operations..

 

Sweet, thank you for the Cliff's Notes! Can't get any simpler than that...lol

 

Got the cylinder and head on, bolts greased and torqued...

Rings are no fun...I bet I spent 30 minutes trying to get the cylinder down over the rings... didn't use anything, just my fingers and a bunch of cuss words... next time I'll make sure I have a large hose clamp or zip tie on hand. Lesson learned.

Crank moved while putting the cylinder on so I had to find TDC again while holding the chain. Engine rotates smoothly by hand through several revolutions.

Done for tonight... tomorrow I'll put the cams back in.

 

Got her about 95% back together. Turns nice a smooth with the spark plug removed. Radiators are full of coolant. Exhaust is on. Only parts left are the bodywork.

I still need to change the oil for standard 10w-40, change the main jet, and double check everything.

With any luck, I'll crank her up tomorrow and get her broke in...

 

Try and post a video of the startup. That was a really good deal for the BB.

 

WOOT! (Yeah.. I'm old skool)

1st run and break-in done.... 4th gear full throttle roll-ons....Dayuuuum!

Let her warm up and last check for leaks, then out to the road for 4 or 5 - 1/2 throttle 4th gear 4k-> 6k->4k cycles, then 4 or 5 - 3/4ish throttle 4k-> 8k-> 4k cycles, finally 6 or 8 full throttle 3k-> 9Kish ->3k cycles.

I will admit that at that point, I just did a few extra cycles just to feel the rush. 4th gear 3k full throttle roll-on is impressive... back end gets a little loose (I was up on the tank...lol)

I'll be using much less clutch in the tight stuff *grin

She's out cooling off now.. don't see any leaks anywhere. Still need to fine tune the manual CCT. Probably have to adjust the air screw and check my exhaust as I had more decel pop than normal (running a 40 pilot). Vibes were ok, more thump than vibe but noticeable.

Two thumbs up! Thanks for all the help!

PS: I'm still waiting on heavier Barnett clutch springs, and will change out 3 of the stockers at my first oil change.

 

Sorry man... didn't see your post till after.. and didn't take any video (you know, in case she came unglued... no evidence LOL)