1st rebuild question

[Sweendogie]

im rebuilding my top end and i always run synthetic oil... but i was told not to use synthetic oil to break in the top end because the rings wont set properly.... so when i break it in it should be alright to use conventional oil shouldnt it? also what do you guys all do to break an engine in? ive searched a lot but want to know what the guys running yfz's are doing

[Ride1Rob]

It's pretty much what you're most comfortable with on the breakin. Every motor that I rebuild I heat cycle. Have one that I just put back together that I'll start cycling later today. Since I've been doing this (about 3yrs) I haven't had the 1st issue with the rings seating properly. The old conventional way (riding it nicely for the 1st 10 hours or so) never gave me any issues either other than ALOT of wasted time :rolleyes: . In a little less than an hours time total on the motor of heat cycling I'm already riding the quad like she's meant to be rode (HARD). It's alil funny to me when I meet guys that just got a bike and have had it for almost a month and are still afraid to ride it hard.

Look at the pro racers for example. They build those motors after every race. I don't think they putt around on them for hours before they ride them balls to the wall. I would think they heat cycle them as well.

[stoopidbot]

http://www.mototuneusa.com/break_in_secrets.htm

Read that article, that is how you should break in a motor.

[miles Machine]

for break in you should use a motorcycle grade sae non synthetic oil...i stress motorcycle grade oil because they have friction modifiers, anti foaming agents, and detergents in them for use with clutches...if you use a automotive grade oil you could prematurely wear out your clutches...now ik theirs gonna be someone on here that will say well ive never had a problem and i run automotive oil but they ether are lucky or just are not noticing the reproductions of it....also what was mentioned earlier with heat cycles is exactly what i do...heat cycle it twice at idle, let it fully cool down, then after that take it out about 2-3 times all 20 min rides then bring it back let it cool off and after the second or third time drop the sae oil out, fill her with synthetic and install a new filter and your ready to rip

[proctorbc2005]

Originally posted by miles Machine
for break in you should use a motorcycle grade sae non synthetic oil...i stress motorcycle grade oil because they have friction modifiers, anti foaming agents, and detergents in them for use with clutches...if you use a automotive grade oil you could prematurely wear out your clutches...now ik theirs gonna be someone on here that will say well ive never had a problem and i run automotive oil but they ether are lucky or just are not noticing the reproductions of it....also what was mentioned earlier with heat cycles is exactly what i do...heat cycle it twice at idle, let it fully cool down, then after that take it out about 2-3 times all 20 min rides then bring it back let it cool off and after the second or third time drop the sae oil out, fill her with synthetic and install a new filter and your ready to rip

This is almost exactly the same method I used a few days ago, Only I rebuilt my entire engine, From stock to performance parts. In fact my mechanic (guy with 20+years experience) who I trust completly, is the one who did it.

[trx400 rider]

ok so im rebuilding my dirtbike motor friday. you are saying to use what kind of oil?and i should drive slow at first to look for leaks and to warm up the motor.then i should just punch it through every gear and ride it hard is that correct.

[miles Machine]

nope after youve done a couple warm up cycles and youve let it cool down, your gonna want to take it on 2-3 15-20 min rides in between each let the engine completely cool....ok now when your on your break in ride you want to shift up and down all through the gears and go up and down through the rpm range but not high in the rpm range...after the break in ride drain the non synthetic motorcycle grade oil and remove the oil filter...then simply replace the oil filter with a new one and fill with your choice of motorcycle grade synthetic oil


hope this helps
Chad

[trx400 rider]

ok sorry but what is a heat cycle im kind new to rebuilding.

[trx400 rider]

or warm up cycles

[trx400 rider]

ok i get it sorry thanks every one

[trx400 rider]

and how long should it take to break it in throgh all the gears

[daddio]

Originally posted by stoopidbot
http://www.mototuneusa.com/break_in_secrets.htm

Read that article, that is how you should break in a motor.

In the last 2 years I have been breaking our motors in this way, and they seem to run harder and last longer. In fact, the last motor I tore apart still had the cross hatching after 10 hrs of racing.

[miles Machine]

well you can do it your way if you desire i wouldnt recommend it because i think your just getting lucky....however i bought my 450r brand new in jan 06...i did my method...raced it for 2-1/2 years plus all my practices, trail rides, and goofing off...i did change the oil religiously tho every week, but when i took it apart it to still had cross hatching