2 stroke and 4 stroke proper break in procedure?

[roger86200x]

Hey,

Ive got an 84 250r motor (2stroke) and an 86 200x motor (4stroke) I am about done rebuilding...

I need to know the proper break in procedure for each of them...

If it matters:

The 2stroke 250r has new crank bearings, new connecting rod, new connecting rod upper and lower needle bearings, new wiseco .020 piston and the cylinder bored.

The 200x 4 stroke has new valves, new springs, all new valve clips and hardware, 10.25:1 wiseco piston .020 over, bored cylinder, and obviously some head polishing...

Just wondering if things like new conencting rod or crank bearings changes the break in...

Roger

[300rman]

well, there are mixed feelings on the subjct, but it is widely accepted to not beaton it on the first startup.

on both, a warmup/cool down cycle at idle, then ride both easy for about 20 minutes, letting it warm up, but not revving it up high, and then park it and let it cool down.
after that, go for another ride, j and sort of "work" your way into running the motor, and you will be fine. just dont sustain high-rpm very long until a few tanks of fuel have been run through.

anyone think that this would be a bad break in? thats how i did my R, and it runs fine, no problems :D

[RID3R]

With me I ran a completly rebuilt engine before no problems. It was 2 stroke though, dont know about 4. I had no problems at all with it. Its really up to you..

[Tri-ZNate]

I think the most important part is making sure you use assembly lube on the cam journals and such for the first start-up. after that just pick a way that doesnt tell you to go WOT on start-up with it

[Atc GuY]

Yep, no WOT. Be easy on them. I've also heard of people mixing 2 pingers gas rich to give more lubercation... just a thought. Also heard of using some 2 stroke gas in a 4 stroke... but that's just over the top! Just be easy on it and you'll be fine.

[joe_f7]

good info here that i'll swear by. long arcticle, but alot of good info.

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

[sbjones73]

i have heard something like this article before.

so what he is saying after warming up your engine. go and run it wide open and hard decell, then wide open again.? correct

i have actually had to do this on a detroit 60 series engine (diesel) and then took the head back off right away. the piston was cleaner than ever. i have had to do this 2 times before on a regular break in. and the pistons were already showing oil on top. so i can believe this som what, not sure.

[beets442]

Be good to it for at least 5-10hrs. CHANGE OIL!!!!!.If there are any particals in the oil you don't want to keep cycling thru your fresh engine. I believe one of the main things on any breakin, is NOT to stay at the same rpm for a long time. BEETS

[fabiodriven]

good info here that i'll swear by. long arcticle, but alot of good info.

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

I just read that whole thing and signed up for the newsletter. That dude seems really smart. Good job posting that.

[joe_f7]

the main thing is not to keep it at a steady light load throttle position. the motor needs a load on it to break in the rings, and you also don't want to hold it wide open for a long time. short bursts are ok. keep the oil clean on a 4 stroke. i would warm the motor up for the first time maybe even drive it around the house once and dump the oil right away to get the initial break in grit out. then go a few hours till the next change. 2-strokes run hard, but again without long burst of WOT. vary the throttle and load on the motor just like the arcticle. i've always done this with all my snowmobile motors, and they've always run strong. that moto man that wrote the arcticle has interesting stuff on porting too.

[roger86200x]

Thanks for that article.... that guys website has a LOT of good info on it...

Im getting my cylinders bored this week/weekend sometime... whenever I can get down there....

I'll try his break in procedure on the 4 stroke and see how it goes... It all seems to add up.

The 2 stroke I havent heard a lot on.... just no long WOT and not to stay in the same rpm range..... what about the oil? does it need to be changed too? (2 stroke)

Roger

[joe_f7]

well the 2-stoke engine oil is mixed, but if you have a brand new tranny i would go for a short ride and then dump the oil.

[roger86200x]

lol, I know its mixed.... but the engine should still have some metal shavings falling down into it from the cylinder.... they could get into the tranny, etc right??

What oil should be used in the bottom end of the 84 250r?

What oil:gas ratio should be used? (yes i know the oil is 2stroke and not case oil, lol) The guy who I got it from said he THINKS he ran it 32:1 but he wasnt sure... so what should I run it?

Roger

[Tri-ZNate]

the tranny is completely separate, so no shavings will get into your tranny oil. Also that is the reason you mix oil with gas unlike a 4 stroke.

[Hoosier_Daddy]

All the advice here seems gear toward 4 strokes.

I read over on Kawieriders a guy who has been building engine (aparantly owns a shop with a partner) says that when he get's done rebuilding the top end he starts it up and lets it get up to proper engine temp then rides it hard revving it out and going through all the gears and continues to ride it hard without overrevving it for about 15 minutes straight because, in his experience, you only have that initial short time to get the rings to properly seal. Anybody else around here do this method?

[roger86200x]

the tranny is completely separate, so no shavings will get into your tranny oil. Also that is the reason you mix oil with gas unlike a 4 stroke.

OK... but what oils the crank bearings? Isnt it the bottom end oil?

Roger

[joe_f7]

All the advice here seems gear toward 4 strokes.

I read over on Kawieriders a guy who has been building engine (aparantly owns a shop with a partner) says that when he get's done rebuilding the top end he starts it up and lets it get up to proper engine temp then rides it hard revving it out and going through all the gears and continues to ride it hard without overrevving it for about 15 minutes straight because, in his experience, you only have that initial short time to get the rings to properly seal. Anybody else around here do this method?

yup exactly how i do it.

[joe_f7]

OK... but what oils the crank bearings? Isnt it the bottom end oil?

Roger

the gas oil mix lubes them. the crank case is completely sealed off from the tranny.