how do you guys break in a new motor?

[mikey's250sx]

i just finished my 300r and am looking for advise on break-in. i don't want to burn it up because i will have a hard time finding a piston.

i planned on just gentle riding for a tank or two across a field and back running rich and i already have 3 spare plugs to take along.

[oddball3]

Keep varying the throttle from about idle to 3/4. give it a couple WOT bursts but not holding it for long, and don't stay at a constant one speed for a length of time. Thats how I always did my motors, from trikes,sleds, and jet-skis.

[BigGreenMachine]

Two stroke, I warm it up to operating temp, kill it and let it cool down completely, retorque the head nuts and then ride it like I stole it. (assuming your jetting is spot on)

[TravEX]

This was posted at ATVRiders.com for TRX R's by beerock, sounds good to me.

"How to break in your motor
This is for everyone trying to figure out what they really need to do to break there motor in correctly.
There are plenty of variances to this, there are also people that will say as soon as its built you can scream the motor right away, I dont believe in this procedure, you can glaze your bore doing that and score a piston. I know theres some guy on the internet with a site about running your motor hard right after being built. LOL


first do a compression test, if its over 185 psi you will need to run race gas. MY SUGESTION is to run AMSOIL dominator oil at 50:1 This is the best oil on the market in my opinion. If you want to run another brand thats great theres tons of good oils out there. Whatever oil you run make sure you consistantly mix it properly and try not to use other brand oils.(unless your in a pinch.

once you figure out your compression psi. mix the oil and fill your tank. dont eye up the oil use a ratio rite or use a maxima pre mix(what i use its great)

start it up and blip the throttle until the cylinder gets warm DONT ride it or put it in gear. Once the cylinder is warm to the touch shut her off and let it cool completely. do this 3 times.......

then ride it varying the throttle from 1/4 to 1/2 throttle then let it cool completely do this 3 times!!

after this ride it from 1/4 to 3/4 throttle then let it cool completely do this 3 times!!!

after that ride it from 1/4 to WOT, DO NOT HOLD IT WOT just constantly roll the throttle on and off, no abrupt throttle. do this 3 times with a cooling cycle in between each time.

after this you should be done with your tank of gas, fill it up and ride it gently for the next gas tank keep rolling the throttle on and off. after the second tank LET HER RIP!!!!!!!!!!"

Here's the link http://www.exriders.com/vbb/showthread.php?threadid=196570

[TimSr]

Keep varying the throttle from about idle to 3/4. give it a couple WOT bursts but not holding it for long, and don't stay at a constant one speed for a length of time. Thats how I always did my motors, from trikes,sleds, and jet-skis.

Thats pretty much what it says on the Wiseco instruction paper they used to send out with their pistons. This is a two stroke procedure, if anybody is wondering. It only takes about a 1/2 hour at best to seat and break in a two stroke top end, according to Wiseco and I agree with them.

4 strokes have a whole different set of variables, but thats not relevant to this thread.

[TeamGeek6]

Extremely rich doesnt help much, increase the premix and ride like the owners manual recommends, after all, it was written by the engineers that designed the engine...

[peeweesp]

well i read this on another fourm i frequent not so long ago, i wish i still had the site but there is a guy that disaggress with the take it easy approch he uses the "moto Man break in" heres a link dose it work people have there own ways do what you think.

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

(keep in mind it was probobly only tested on streetbike engines, i just thought i would throw it out there, like i said do what you think is right)

[Hornetpowerspor]

I agree with everyone above. However different applications require different break in. If all of your tollerances are to OEM specs, break it in like the owners manual says. In many cases, especially racing applications, clearances are set loose. Hopefully you checked your piston to cyl clearance during assembly. Seeing that you have a big bore kit, I would be curious as to what tolerances your machinist left when it was bored. When you have a .003-.0045 clearance on a 64-72mm bore, you don't really need to apply the (cool down ) step because there is no real chance of seizing your piston, assuming your cooling system, jetting and oil premix are correct. Just my 02 cents;)

[Tri-ZNate]

It sounded like he knew his stuff till I got to the "Smaller ports actually make more power than bigger ports" part :rolleyes:

[Jason Hall]

If it has a wiseco piston, heat cycles is what you want to do. From what I have learned you want to warm it up & let it completly cool down. A wiseco is a forged piston, that is compressed in a mold while still a liquid. Because it was under pressure when made it naturally wants to expand out. Once it has enough heat cycles the molecules will settle to it's permanent size.

[mikey's250sx]

well this is what i may have found out. the part # off the box from the piston at service honda comes up 300cc kit 1984 (1.00)

does thet mean a 1.00 overbore?

honda part # 13105-964-810

it is not a wiseco piston. are the original honda pistons cast or forged?

if it is a 1.00 overbore what do you think that would be for actual displacement?

i guess it is a good thing i kept the original cylinder too if i can't bore this one again.

as fas as the break in i get the idea to take it easy for a bit, change up the throttle position, and let it cool , and check the head stud torque.


thanks

[blue27]

"BREAKING IN ENGINE: Start engine. Warm up for 2-3 minutes. Ride at moderate speeds for 10 minutes. Shut off engine. Allow engine to cool completely. Repeat 5-6 times before racing your TIGER" this from the Tiger 200 engine manual. I agree with above take it easy for atleast a tank full of gas and do not hold it a one speed to long do not run at WOT and try nut to lug or bog down the engine. 4 stroke about the same but Mickey Dunlap used to break in my race motor by starting it up and giving it a couple of good revs from idile to full and said that was good enough, ride it and check head torque. Good Luck

[crackshot]

Depends if you want it to go fast or not.
If you want it to be a slug butt, baby it and run it slow.
You want to make it fast, run it hard and it will run like a raped ape!

[OldSchoolin86]

Warm it up slow, take it for a 30m leisure ride then beat the hell out of it. Don't just let it sit there and idle tho, warm it up by slow riding.

[peeweesp]

It sounded like he knew his stuff till I got to the "Smaller ports actually make more power than bigger ports" part

yeah i saw that, dont know what thats about, but on one of the other fourms i read about the break in many have used it with no probloms, i dont know but if i had a new bike, i owuldnt be able to resist, opening it up.