Run in period?

[Syfoon]

Pretty simple.

Just got the NSR home after its rebuild, only done 20km on its new piston, barrel and ring.

So, how long and how should I run it in?
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Not here...

[badlydamaged]

Im no expert Id guess about 500 miles not stressing the engine too much (not full throttle basically and mainly staying below 7000 rpm) and then gradually giving it more wellie until about 800 miles when you should be OK for full power .

Cheers, Jonathan
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My bike: 1988 Kawasaki KH100 Status: Polluting Devon with two stroke smog and noise pollution!
"Its not your engine size that matters!, It's what you do with it that counts"
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[mr jamez]

I searched for this on the boards a while back, Pretty sure it was Korn who posted:

0-100 miles : 5,000rpm
100-200 miles : 5,500rpm
200-300 miles : 6,000rpm
300-400 miles : 6,500rpm
400-500 miles : 7,000rpm
500-600 miles : 7,500rpm
600-700 miles : 8,000rpm
700-800 miles : 9,000rpm
800-900 miles : 10,000rpm
900-1000 miles : 11,500rpm

And vary the revs as well, don't just sit there with the throttle in the same position all the time, give it some work to do

[yambabe]

He-who-fixes-small-bikes-for-a-living says:

hahaha!

Put plenty of 2-stroke in, then it's really not just about revs it's about load too.

The figures below can be used as a guideline, but how would you go on if you had no rev-counter? Try to keep to no more than half-throttle and use your gears accordingly, and use approx 50 miles per 1000 rpm until you have done about 500 miles.

I hope you make sense of this because I have no idea at all what he's talking about but he usually knows what he's doing!
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Sod falling in love, I wanna fall in chocolate.

[divuk83]

Always give the bike a few mins to warm up just idling. Be gentle for the first few minutes and then gradually get faster.

What kind of cylinder is it? I have generally run all my nicosil ones in for a few hours of gentle riding and they have been fine. Not sure about cast iron ones and the like as they take a lot more running in. Having said that all my cylinders have been thrashed on the dyno to start off with so who can say if running in is that important. As long as you warm it up first, that is the key point.

Dave

[Mr Pants!]

Check your manual, it normally says in there.
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Mr Pants! (Alex or Al)
Its better to burn out, than to fade away....

[stinkwheel]

two schools of thought on that one, One says that you should warm it up thoroughly then thrash the nads off it to bed the rings in. I wouldn't do that if I were you.

The other says 'stick to x-revs for y-miles', I wouldn't do that either.

The way I have always done it is to up the 2-stroke ratio a bit (or turn up the pump) for the first 500 miles, you want to see a blue haze out the exhaust. Warm the bike up thoroughly before riding off (very important) and ride it in a 'steady' manner without putting a lot of load on the engine. This does not mean you can't go fast but don't thrash it to do so, let the engine decide how far it wants to rev. I wouldn't push it into the powerband for maybe the first 100 miles then gradually start dipping into it more and more as you go on. Avoid sitting at the same rev speeds for extended periods, blip the throttle as you go down hills to keep the oil flowing. If you have a fast bit, space it out with a slower bit to allow things to cool down again

After 500 miles you will probably have worked up to using the powerband quite a lot. On one of my older 2-strokes I would then give it a decoke (maybe do the zorst), drop the mix ratio back down, treat it to a new plug then go out and build up to ragging the arse off it by about 700 miles once I was happy it was coping with the new mix ratio and not just relying on the excess sat in the sump from before.

But that's just what I do.

(I have owned and mantained the following 2-strokes: soviet RT125, jawa350, RD350YPVS, Kawa KH350, suzuki T500)
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.