how long do i run in my Stage6 Sport Pro MKII Cylinder Kit - Aerox/ Minarelli Liquid Cooled 70CC ? its on a Yamaha aerox
straight from SRT's website Since the correct way to run in a new engine or brand new parts is a much-discussed subject, I have decided to make a 'how-to' explaining what I think is the best way to do so. First of all, don't listen to people that simply state that a 100 mile running-in period is necessary for every engine. When looking at the best way to run in a new cylinder, the main difference can be found between alloy and cast-iron cylinders. Alloy When your cylinder and/or your piston are new, their first few minutes are the most important. Start up your engine, and let it run idle/low revs for some time until it reaches normal operating temperature (~50 C). After that, shut off your engine and let it cool off completely. Repeat this procedure once more, using slightly higher revs. After this your cylinder is ready to be used. Every time you start up your engine you need to let it reach the normal operating temperature gently before you start giving it full throttle or high revs. Cast-iron Cast-iron cylinder kits require a running-in period for about 50 miles. This running-in means changing the engine revs frequently, and not using full-throttle for long periods of time. So it actually is possible to drive top speed for a short while during this running-in period. Just keep in mind that you change the load on your engine frequently, as well as your engine revs.
Cast iron run in of 50 miles? your kidding, the rings will not have bedded in and you will be heading for some accelerated wear to the bore and piston.
i believe its called a 'hard break in' or something along those lines. its commonly done on motocross bikes. the idea is that by keeping the rings under load over lots of differant rev ranges, they seat better. when i used to put a new piston in my 125, id just warm it up thoroughly, ride slowly for like 10 mins, then ride as normal. it kept loads of compression and never got blow-by.
Not so easy on a ped when the variator is trying to keep the engine within a narrow powerband. Also most motocross engines have alloy barrel and heads.
If its been built properly and you know what your doing. You can run in a two-stroke in around 45min.
Start running at reasonably low speeds with a rich mixture and additional oil in the fuel. If you norally use a 20:1 mix, run-in on an 18:1 ratio for eg. After a bout 15 minutes of operaton at a fairly constant speed, try varying your speed and occasionally use up to about 3/4 throttle. Continue changing your speed for another 15 minutes, but take care not to accelerate too briskly. Prolonged opreation of a two stroke at part throttle followed by a burst of full throttle may damage the engine. This occurs because only a small amount of oil is present in the engine during constant light throttle running. Suddenly opening the throttle severly losds the engine but only a small quantity of oil is available to lubricate at slow speeds. During the nest 15minutes gradually build up to racing speed, but do not use full throttle for more than 200 yards on a straight. Accelerate hard out of the corners for the last 15 minute segment, easing off after each burst to allow the ring and piston time to cool before the next blast. The hard acceleration is necessary to bed the rings into the bore. Do not hold full throttle for more than a few seconds or the rings and bore could overheat and glaze. Takes between 45 to 60min. Make sure your running rich and extra oil.
Its all down to correct set up. Jeting, oil quality, oil ratio, piston to cylinder clearance. Wether or not you chamfer the ports and piston skirt etc etc blah blah
in info that came with my malossi sports 70 say to not pass 3/4 throttle for 45min's or riding, after that you should consider the kit run in cast iron take little to no running it.
i would rather run my polini sport kit in the duration it says in the instruction to be honest 250miles/500kms on 3/4 max then ill give it full throttle i havent known anyone to run in there cast iron kits in 45 minutes until now. instead of messing around with set ups i would rather have one set up then run it in with the correct method
it strange, on the road ppl have massive run in times. with off road, when i had my kx rebuilt i was told to hammer it round the track.
it is strange but if you think about it 250 isnt alot if you have low down grunt with a sports kit 3/4 shouldnt be a problem mileage will fly past