2012 300 running in a new piston

[Weird Rooster]

Top end time. What is the accepted method of running in a new OEM piston? I have read that you shouldn't use synthetic oil for the first tank of fuel? The bike has 75hrs and about 2,500km (1,500 miles).

 

[Jakobi]

I don't do anything special.

Wash the bike. Wash the bike again. Get the job done.

Double check water, coolant, fluids, airfilter - check
Start the bike - check
Operating temp - check
No coolant leaks - check
Then I take it for a ride around the block. No steady rpm. No excessive screaming. Just load the engine up a gear high and let it pull through from idle into the upper mid. Let the engine drop rpm under its own as well (no clutch). After 5 minutes of this I bring it back to the shed. Double check everything again. Inspect coolant leaks. Go over bits and pieces.

Next ride I treat it like I would any other. Bring it up to temp and when its ready let er rip.

No idea if its right or wrong, but its worked for me so far. I don't have the time to be mixing a special tank of fuel for break in - and realistically, you'll still be circulating the synthetic from the pool in the crank cases anyway.

 

[wence]

As above....

 

[Jim Cook]

I concur as well.

In addition, I do not oil the piston rings or cylinder during reassembly, as it will receive lubricant in the premix before it fires the first time.
I feel that this helps the rings to seat properly.

I do oil the wrist pin bearing.

 

[desertgasser300]

All of the above, as well!

 

[Jim Cook]

I set my engines up on the tight side, so a proper warm-up before loading the engine with a lot of throttle is imperative to prevent damage.


.

 

[Weird Rooster]

Thanks for the replies. What ring gap have you guys used on a 300?

 

[n_green]

You'll probably find if you buy a kit ring gap is already acceptable. I've never had to file a ring.
Manual calls for .4mm min to .8mm max or thereabouts doesn't it?
After 25 hrs my '14 still has a ring gap of .385mm top and bottom.

 

[Jakobi]

I've used wisecos calc + a bees dick in the past. Like Jim I set mine up on the tighter side.

 

[desertgasser300]

Wiseco and wossner use the same ring gap and im sure if you could find it Vertex would too.

 

[blamir]

75 is hours is not early to change piston?

 

[Jakobi]

75 is hours is not early to change piston?

Depends how you ride them. I've pulled a piston at 75hrs on my EC300 from new and rings had barely worn. I had moved up from a 250F and most of the hours were getting to know the bike. I've also stretched 110hrs out of an EC250 and rings were at maximum tolerance.

I like to change mine around 85hrs in general, but in saying that my new bikes just over 50hrs (I think - trail tech speedo seems to be playing up) and I can already feel its lost some snap.