Running In An Engine

[mx250]

What's the purpose of a 'run in' on a two stroke? To me it's just a check that every thing is as it should be - tolerances, timing etc.

One heat cycle - careful start up, pick up more and more revs, listening and feeling for any 'locking', fully warm it by progressively putting it more and more under load (more revs, more acceleration). One successful heat cycle - about 10-15minutes - and then go for it.

If it is quality parts put together right it will be right - it's a two stroke - beauty in it simplicity.

Plug chops and tuning after that as per usual for the usual reasons.

[VMX247]

Usually do 3 X 5min bursts waiting untill your hand can touch the cylinder without burning yourself in between.Each 5mins riding round gradually increasing rpm untill you go for the doctor on the the third go.Heat cycling it's called as you want to gradually bring the piston up to it's peak operating temp gradually the first time.
As with a few of the above stories the common element is NEVER keep a constant throttle.Flogging it from the get go is OK in an old air cooled engine but in a water cooled nikasil cylinder you will cold seize within a minute if you do not warm up correctly.  

DITTO

Is a sight lap under yellow flag and who is testing the speed    
cheers

[Freakshow]

bulge it.

I like that term. Bulge it Can I use it? 

I prefer teh term bludge it.

[Marc.com]

Can a bike be run in on the stand.
Does the engine need varying loads.
Ji

Heat cycling, just get it hot a couple of times on the stand and let it cool down between, all running in is doing is bedding the rings and knocking the high spots off the piston as metal things expand at odd speeds.

Ever wondered why rental cars run so well, they get a good flopgging from day one.... or they do if I am driving 

[firko]

I've never run a two stroke engine in...ever. One or two cruise laps to make sure it's been put together properly and then hammer the bejesus out of the forking thing.
I've only ever had two sieze ups in 40 years of owning, riding and racing two strokes and they all perform pretty damn well if I don't say so myself.

[holeshot buddy]

assemble the top end dry
then kick over on kickstart
quickly about 30 times (with tounge out Lh side)
run in

[TT5 Matt]

team kawasaki drop the oil out of there 4t multi's and fill her up with deisel with a hour city riding for there run in on prodie racers and the advice from the guys was if the motor was going to be fired up that day you assembled it using crc on the piston/ring lands and bore to stop carbon from forming in the ring lands and to help bed in the rings,ive used this method for years with no drammars