Cylinder rechromed and new piston

[Lee_250f]

Hey people. I just got my cylinder rechromed and a new piston kit. What do u rekon the best way to run it in is and for how long? should i make my fuel more rich or just leave it as normal wich is 32:1. Its a cr125 by the way if it makes a differnece. Cyas.

[Robbo66]

depends. i take it you have more compression? try it out with 32:1. i dont see why you would change it.
see how it goes, report back here, and im sure, us fellow fmxaus'ers would be happy to assist you:)

[Lee_250f]

yeh i didnt no if i shoudl run more oil just to make shore the rings are really well lubed and stuff. how should i run it in....just put around or just hit band and then get out or what, and how long should i run itin for like a tank or wat?thanks

[[TOPGEAR]]

just lube it all up before u put it together and run it at the ratio u normally run it at.

theres heaps of different ways u can do it.

1 i have heard. start the bike and give it revs till the barrel is hot. then leave it till its stone cold (2hours maybe) or just leave it over night. repeat that another 2 times. then go out for a 15 minute ride with no powerband and nothing over 1/2 throttle. let it rest for about 30 minutes and then u are right to go.

2nd one. start the bike, warm it up. go for a 10 minute ride (nothing over 1/2 and no powerband) making some short gear changes and not reving it out in one gear. then let it sit for 30 minutes. go out again this time go a bit faster and get some powerband happening but not too much. and still nothing over 1/2 throtle. then let it sit for 30 minutes. then after that u can go as fast and as hard as u want.

i've heard heaps. personally, i use the first one.

ive siezed an engine not doing it right so just be careful and follow instructions.

and if u do one i said and u blow ur motor up. dont sue me haha

[Lee_250f]

lmao. yeh sweet. thanks topgear. its jsut that ive heard so much differnet shit about running in bikes. few people told me jsut jump on and rev the absolute crap through it but i didnt think that would be right.

[[TOPGEAR]]

nah dont do that.

ive used both the methods i said. the first one i used for the topend and the second i used on the bottom end.

[Robbo66]

they are both wrong. you have to get the piston used to being hot, and going cold.

Do not ride at a sustained RPM for a long time.

Operate bike in “normal” manner. Ride for 5 minutes. Turn off and let cool down for 5 minutes. Then ride for 10 minutes and the turn off and cool for 5 minutes. Continue this adding 5 minutes of run time until you reach 30 minutes. Bike is then broken in. (This procedure takes time and patience. When done properly the rewards are great.)

It is important that during this break in time the RPM is varied constantly. Do not run at a sustained RPM for a long time. If you are cruising at 25mph for a minute, change to 30mph, etc. Do not put on a stand and let idle for any part of the break in period. Engine needs to have air going past it and the RPM constantly varied.

EDIT: Another thing people think is 'oh, I'll put more oil in the premix when breaking the new top end in'. This actually makes the bike run LEANER and hotter.........if your lucky it might even seize.

by leaner, i mean, you add oil to the fuel, which will richen the fuel, but will lean out the fuel and air mixture.

[[TOPGEAR]]

they arent wrong, its probably just cause u havent heard of them before.

i have used them both twice and they have worked fine.

[Lee_250f]

well this is ehat i am gonna do. first ride ill just go round slow withput band until the cylinder gets fairly hot. let it go stone cold then do that gain. each time for about 15minuts. the third ride hit band but only just and then let it off straight away through the gears. then let it cool and do it agian. then go again after cooled and start gettin into band properly and let cool again then shell be ready for a floggin. if u think this is not good please let me no ur reasons. thanks.

[[TOPGEAR]]

yeh, just about anything works as long as u dont rev the **** out of it and go as fast as u can

[Robbo66]

read my post. dont stay at a consistent rpm and your fine. you can hit powerband if you want. just dont hold it there.

[Robbo66]

another thing..

where did you get it done?

[kyle]

run it at 40:1

start the bike and let it idle for ten mins, then let it sit for 20, start and idle for 10 again and then ride for ten no powerband, but hard and then you are ready to go, done it three times on my 125 and that is how to the piston seated in the barrel for most power.

[[TOPGEAR]]

yeh thats similar to what i said, there is a heap of different ways. just do whatever the shop said where ever u got all the shit from.

STEP 25: BREAK IN
There are many different theories on break in procedure, so here is ours. Basically, when breaking in an engine, you do not want to strain it in anyway, never go above 3/4 throttle, don't ride in sand and try to keep it on flat ground:
Note: You will be riding the bike at half throttle. To avoid fouling the plug, you may want to install a hotter one.

1) Start the bike and warm it up. Ride for about 10 minutes at half throttle. Shut it off and allow it to cool.

2) Check for any leaks and noises and pull the plug to check it.

3) Start the bike, warm it up and ride for about 20 minutes. Shift through the gears, but do not use more than half throttle. Allow the bike to cool. Check all components of the bike, look for leaks and check the spark plug.

4) If the bike looks good, not making any funny noises and is not leaking, you are good to go and the bike is ready to be put through its paces.

[Mungoman58]

Originally posted by kyle
run it at 40:1

start the bike and let it idle for ten mins, then let it sit for 20, start and idle for 10 again and then ride for ten no powerband, but hard and then you are ready to go, done it three times on my 125 and that is how to the piston seated in the barrel for most power.

Dunno bout this letting your bike idle for 10 mins???? I woulda thought that would do more harm then good. How's the bike suppose to stay cool when its not moving?? Oh and another thing I don't think anyone has mentioned is that after your first ride park it and check for leaks. Then after a few more rides park it and check that bolts etc are still all tight

[Lee_250f]

yeh well i was supposed to be riding this weekend but my parts havn came back yet. is been 3weeks now and i starting to get pissed off and thanks with all ya comments on runnig it in.

[[TOPGEAR]]

thats nothing, i waited 6 months for my shit to come from japan. then one day i was sick of waiting so i called a few places in QLD and got the parts the next day lol

[Lee_250f]

yeh im just pissed off cosue i got the bike and 2weks later it blew up. my bike shop told me no longer than 4days and now its 3weeks and ive really been wanting to ride!lol cant ever go without a bike.

[[TOPGEAR]]

i had mine 2 days and it blew up. didnt completely blow up but it ****ed the conrod & all the bearnings.

ring him up and say why is it taking so long, u said 4 days. say u missed out on a holiday where u had to put down a non refunable deposit and u missed out lol. maybe u might get $100 back off them

[Mungoman45]

In this day and age, service standards are piss poor to say the least. When they say 4 days, they really mean 4 weeks. Dont listen to a salesman when they tell you an estimate on time of delivery, as it is just that, an "ESTIMATE", and an uninformed one at that, as they have no idea whether parts are in stock from where they have to order from, nor do they know how long it will take to get them delivered....

Now, the waiting game sucks, so lets all play hungry, hungry hippo's. :smoker2:

[Lee_250f]

Hungry hungry hippos......ive already broken the bloody thing since my last bike also blew up on me and took ages to get fixed.lol.