Break in.

[traxxasx]

Well im getting my jug back tommrow with a new piston rings eveything. I want to know the proper way to break in my 82 r because it seems like the previous owner messed up on that and thats why im having to replace a brand new top end. Please tel me good steps to a proper break in, thanks.

[MRPoopie]

http://www.duncanracing.com/techfaq/Tech_2-stroke-engine-break-in.phtml

[Liquid-Darkness]

Slap it togeather with a clean air filter and some 32:1 fuel. Ride it around for an hour under 1/2 throttle or less. and listen for noises. Take it home and let it cool, retorque head bolts/ cap nuts. Do this 2 more times, then jet for power.

I suggest putting on a Paul Turner High Rev with some type of FMF silencer<Turbine Core with built-in sparky> and some stock reeds+stops before you break it in. If they make that exhaust for an air cooler.

[chris200x]

Slap it togeather with a clean air filter and some 32:1 fuel. Ride it around for an hour and listen for noises. Take it home and let it cool, retourqe head bolts. Do this 2 more times, then jet for power.

I suggest putting on a complete DG exhaust system and some boyesen power reeds before you break it in. That would make it a quick air cooler.

I'm kinda curious about the proper steps aswell. Can running it for a few hours without it being jetted properly hurt anything? Do you go easy or balls out?

[SYKO]

well I heat cycle mine 4 times (start idle blip the throttle a few times for about 3-5 mins then shut off) then I easy ride for about 10-20 mins a few times then let cool a few times, then after all that I get CRAZY!! and rip like a tidal wave is behind me!! also use hot soapy water to clean out the cyl and then dry before you assyemble it, and use a little 2 stroke oil in the assy when you do everything should go tegether like money and a whore (real easy) then after a couple of rides retighten all bolts.

[SWIGIN]

Riding it under 1/2 throttle while its lean will not hurt anything.


how and why wouldnt it hurt anything?

i do like syko does with a retorque after it cools every time till the gaskets stop compressing.

but on a air cooler this wont take long...maybe once or twice

[Billy Golightly]

I usually heat cycle 4 times, blipping the throttle up to 1/4 the first time, 1/2 the 2nd time, 3/4 the 3rd, and up to wide open on the 4th. Make sure its completely cooled before you attempt another cycle, and as mentioned check all nuts and bolts, retorque everything. I am not a fan of putting oil in the cylinder before it first runs, as it in my opinion makes the cylinder walls much easier to glaze over then if you start it "dry."

[Bryan Raffa]

I put very, very little oil in mine when assembling like billy was saying about glazing.. the first time I start it I let it run for 10-15 min just idling maybe a few 1/4 throttle blips thats it!.. Let it completely cool,,Ice cold... re torque the head, then the second cycle I let it idle for about 10 min and give it a ride using varring RPM's But not wide open, And not holding it to one rpm too long..let it cool completely,,Re touque...99% of the time I find this not necessary but I have gotten use to doing it this way and it just makes me feel better when I check it for the 2nd time..then I ride it normal with a little extra oil in the pre-mix.

[traxxasx]

geez thanks guys, im actually kinda scared to do it because it costed me 210 for the piston kit, gaskets, bore. So yea hope i do it right.

[traxxasx]

Ah stupid lazy people down at sams bike shop dident even bore my jug. They got my piston kit and gaskets but dident do a 30 min bore. Its been a week since i left my jug with them and they dident do it that whole time. Ruens my day, todays my only day off and i was hoping to get it running right today so i can go out this weekend and ride but some lazy people ruend it. Pisses me off. They quoted me it will be done either before next wensday or wensday morning. Yea whatever.

[SYKO]

hey man make sure they know that an air cooled motor needs alittle more for tolences when being bored than a liquid cooled motor!!!

[traxxasx]

Got my cylinder gaskets piston and everything. Im goign to put it toghther tommrow. Break it in and hopefully fixes my problem. Then to the dunes i go this weekend. Hope it does well with regular knobbies with low psi. Other than that im going to ride it for maybe a month and then to the classifieds it goes.

[Dirtcrasher]

I've broke in quite a few motors. It always makes ya a bit nervous when you've dropped hundreds of dollars into something you feel could blow up again and you want to get it right. When I was 16yo I threw a chain into my clutch pivot on my 1981 RM125 motor and it cost me 700$ to rebuild the whole motor. I was terrified that it would seize unless I broke it in right and spent alot of hours going easy on it. Through the years I learned a process that worked better for me.

Four stroke or Two stroke, I just take it easy like 1/4 to 1/2 throttle for a half hour. Then I let it cool down and do it again with little bursts of 3/4 throttle. Most important thing is to vary your speed and dog it around a bit.

Next time out I ride the same varying throttle and add just a quick burst of wide open throttle and always vary the speeds and throttle. Cool it down for 20 minutes and repeat.

I feel safe after about 2 to 3 hours and ride it near normally at that point. when I've done that for a bit I feel comfortable to hold it as wide open as long as I like.

I never changed the mixing ratio on a 2 stroke but I do change the 4 stroke tranny oil often during the break in time. This procedure has always worked well for me.....

If you have the time you can break in a completely rebuilt motor in a day. What do you think a professional racer like James Stewart does? If he changes a top end on race day there isn't nearly any break in procedure done to it at all.

[traxxasx]

I've broke in quite a few motors. It always makes ya a bit nervous when you've dropped hundreds of dollars into something you feel could blow up again and you want to get it right. When I was 16yo I threw a chain into my clutch pivot on my 1981 RM125 motor and it cost me 700$ to rebuild the whole motor. I was terrified that it would seize unless I broke it in right and spent alot of hours going easy on it. Through the years I learned a process that worked better for me.

Four stroke or Two stroke, I just take it easy like 1/4 to 1/2 throttle for a half hour. Then I let it cool down and do it again with little bursts of 3/4 throttle. Most important thing is to vary your speed and dog it around a bit.

Next time out I ride the same varying throttle and add just a quick burst of wide open throttle and always vary the speeds and throttle. Cool it down for 20 minutes and repeat.

I feel safe after about 2 to 3 hours and ride it near normally at that point. when I've done that for a bit I feel comfortable to hold it as wide open as long as I like.

I never changed the mixing ratio on a 2 stroke but I do change the 4 stroke tranny oil often during the break in time. This procedure has always worked well for me.....

If you have the time you can break in a completely rebuilt motor in a day. What do you think a professional racer like James Stewart does? If he changes a top end on race day there isn't nearly any break in procedure done to it at all.


Thanks for some comfort. I just hope i can throughly break it in tommrow so i can ride it full blast at the dunes on sunday. Hope all goes well.

[3leggeddog]

some very good info there.i agree with some but disagree with others.heres what i do....


use very,very little oil during assembly.brsure you got a good hone!if you didn't change a whole lot,your jetting shouldn't change much from a bore,and new piston.

fire it up,and rev it up and down 1/4 throttle till it's warm.don't let it just idle,this is a good way to glaze the jug.just rev it lightly.once the machine is warm,ride it!you need to put a load on the rings for them force out against the cylinder wall and wear to the shape of the cylinder.even though it's a fresh bore,i gurantee the cylinder is not 100% perfectly round.you nees those rings to wear to the shape of the jug,to do this it needs a load.so run it through the gears,1/4 throttle.let off ,and DO NOT PULL IN THE CLUTCH!!
slowly downshift back through the gears.the motor will have a greater scavenging effect if you let it engine break.this will help pull out all those little particles of ring you just created by loading the rings.after the 1/4 throttle run,do a 1/2 throttle run,same way,hold it at half throttle,run it through all the gears,and engine break.then let er cool.retouqe everything.next do your 3/4 throttle run,then a w.o.t. run.let er cool,retourqe everything,to the manufactures specs.,and your done.change the crankcase oil on a 4 stroke,and change the pulg on either 2 or 4 stroke.fresh plug,and rip it up.

i got all my info from motoman.com.i have done this the last few times,and everything has been gravy

[traxxasx]

Well i put it toghther and was breakin it in and when i went to put it away for the night it died. I tried to kick it over and all it will do it start for a secound and die, its dark now and the po pos are around i cant mess with it anymore and tomrrow was my day to go to the desert and its not ganna happen. This is lame and gay. I think im just going to sell it for 900 cash. Ill let ya know tommrow its going into the classifieds.