TZR50. After rebuild how long do I need to run it in for.

[icedragon]

I have just put a 90cc kit on my tzr. I got it from Poland and the instructions said to run it in do 500km (310miles) at no more than 30kmph (18mph) and then a further 500km (310mph) at no more than 40Kmph (24mph).

Is this right. Surely them speeds are Illigal to start with. Plus that would take me about a year to cover 620 miles.

If its right I have no choise I suppose

[Ryan09]

Iv read mixed opinions of running in a 2 stroke, some say rev it hard from day 1 and others say dont go over half throttle for a few hundred miles. Either way those speeds you put up are ridiculous and youll be pretty bored by the end of it..

[nayruf]

Hi

We used to run in Maico motor cross pistons in to a new bore by starting the engine allowing the engine to warm up with very little revs, then we would let it cool down and re-torque the head/barrel, then ride around on a few slow laps, then just ride as normal, bearing in mind that these were race bikes and the piston life can sometimes be quite short.

So I should imagine that providing you allow the engine to warm up then let it cool fully followed by a re-torque then run the engine without over or under stressing it for a 100 miles or so then it would be ok, I did the same to my DT 175 after new mains, small end, big end a con rod and a new piston in a freshly honed bore and that was over 2000 miles ago,

Good luck have fun and don’t hold it against me if it goes pop

[icedragon]

Iv just been riding it at just touching 30 for now. I don't go out on it much so running it in will take forever

[slice]

Running in is about NOT overstressing the engine, it has nothing to do with speed and has everything to do with being gentle with your engine so DON'T go flat out nor run it really slow in low gear let it run freely using gentle throttle and gear shifting and you should be fine in aboiut 250 miles, all my rebuilds have been treated this way and I have never had a problem, tell a lie my AJS used to eat crank pins cos it was badly designed but your bike is well made and can take it if you treat it right.

[DirtyDT]

........................... Surely them speeds are Illigal to start with.....................

Only on a motorway.

I would be more worried about being passed by a bloke with the Olympic torch doing an amateur jog.

[icedragon]

Haha

[drewpy]

i rebuilt an auto scooter with a fresh cylinder.

the clutch bites at 5k revs so you have no choice on the engine speed TBH.

good advice on tickover and letting it cool, re-torquing head.

just don't let it under or over rev IMHO.

[Gringo]

if you just drive carefully when its cold, so can you give it full gas when its the right temperature i use to do it at that way and i have never broke a cylinder!!