help running in a 2000 yz426f


3 replies to this topic
  • nathanyzf426

Posted June 17, 2008 - 02:54 AM

#1

gidday lads:busted: just wondering if you can give me some pointers apperently i have to bed the rings in by kicking it with no oil with the spark plug out 50 or so times then once going first 15 hours 1/4 throttle then i cant remember for certain but i think it was 20 hours 1/2 throttle and so on any tips on good oils you would recommend for this it has just been totally rebuilt due to conrod breaking and stripping out the inside including putting holes through cases and barrel it has just cost me around 2500 bukks to fix and really dont want it to cost me any more i have been trying to find out everywhere but nothing that i could find i am a 2 stroke fan but have just moved onto a fourstroke as i picked this bike up off my mate already damaged:censored: cheers nathan

  • matt4x4

Posted June 17, 2008 - 05:20 AM

#2

That sounds pretty extreme to me - 15 hrs at 1/4 and 20 hrs at half.
If your cylinder was replated/honed, you have the crosshatch nice and fresh to bed the rings, outside of that there really isn't anything else you need to worry about.
Don't kick it 50 times without oil - you have quite a few bearings in the bottom end that probably want some oil, but that's just a guess. :thumbsup:

My break-in is as follows:

I crank the engine manually about 10-15 times when it's still on the bench to test and make sure everything is turning smooth.
After install in the bike, I start it, let it idle about 5 minutes while checking that the heat is coming up right and nothing is getting hotter than it should, checking rads, hoses, head, cylinder etc. If you hear strange sounds of course shut it down right away and investigate before further break-in. I shut the engine down, let it cool check my fluids to verify that I have no gasket/seal leaks, (getting coolant into my oil etc.), repeat the procedure once more. Verify everything once more.

Now I ride the bike keeping the rev's lower for about 15 minutes, after riding, once again, I check everything.
I perform that once more loading the bike up a little more.
Once everything checks out, I ride it nicely for about half an hour.
Lastly I change the oil, check for problems there, if everything checks out and I have fresh oil in it, I ride it like I stole it.

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  • grayracer513

Posted June 17, 2008 - 05:54 AM

#3

gidday lads:busted: just wondering if you can give me some pointers apperently i have to bed the rings in by kicking it with no oil with the spark plug out 50 or so times then once going first 15 hours 1/4 throttle then i cant remember for certain but i think it was 20 hours 1/2 throttle and so on any tips on good oils you would recommend for this it has just been totally rebuilt due to conrod breaking and stripping out the inside including putting holes through cases and barrel it has just cost me around 2500 bukks to fix and really dont want it to cost me any more i have been trying to find out everywhere but nothing that i could find i am a 2 stroke fan but have just moved onto a fourstroke as i picked this bike up off my mate already damaged:censored: cheers nathan

I don't know where you heard all of that, but it's ridiculous. If you break in an engine like that, the rings will never seal properly.

Start the bike and run it for about a minute, then warm it up for about 10 more by riding it around in 1-3rd gears, not applying much load. Shut it down for 5 or so while you check it over for leaks or loose stuff.

Then take it out and ride it at half speed for about ten minutes. Don't lug it hard at low RPM, and don't go past 2/3 throttle. Let it sit for 10 more minutes.

Now go ride it. Again, don't lug it, and don't run it as hard as you can, either. Just ride it. Give some gas and make it work a little. Accelerate through three gears, coast, accelerate some more. Work it at about 90% of what it's capable of for about an hour. Change the oil, and ride it. It's broken in.

I have no idea what's available in Australia, but find a good high quality synthetic oil suitable for motorcycle engines, like Amsoil MCF, or Mobil 1 Racing 4T, and change it every third ride day or less. And yes, use it for break in, too.

  • nathanyzf426

Posted June 18, 2008 - 12:52 AM

#4

cheers for all the info much appreciated i have a pretty good insight on what is needed to run it in, yeah my mate told me to do all that other crap it sounded pretty out their thats why i asked mind you my mechanic did state what you have pretty well just explained only in another form of words but i guess the more inputs the more understanding i have with it well i never got the engine back yesterday as i was supposed to instead i got a phone call telling me i have to now buy a water pump shaft as the old one was overlooked and turns out its broken also-----breathes----- it is starting to get a bit to much to be honest even though im forever getting told how much i will gain/profit if i was to sell it but the point is im still without a bike and it friggen sukkks well on the bright side my part will b here tomoro and am told i will get the bike back friday in time for the weekend please please please lol as soon as i get the motor back i will put it in the bike and let you boys know how i went cheers again.........





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