Topend Break In Concern

[kave]

Thanks in advance for any help.

Bought my first blaster (2000) and it had a severe air leak at the base gasket. The piston skirt was gone but there was no damage to the cases.

I replaced the crank bearings and seals myself.

Ken bored (66.25) and honed the cylinder and I have it all back together. Held 6psi for 10 minutes.

Only aftermarket parts are FMF Fatty Gold pipe and Power Core 2 silencer. The air box lid is still on.

My concern is running stock jetting for break in. Based on my research of this site, stock jetting is too lean with the pipe. Elevation is <100ft.

What jet sizes will get me through the break in procedure without engine seizure? I will fine tune the jetting after the break in.

Thanks,

 

[blasterdemon7]

I would say about a 280. I would wait a little for other people to give there opinion. In not a pro at jetting.

Edit: I see you still have the air box lid on. If you plan to run without it, jump up to a 290.

 

[kave]

After an electrical problem was solved, I got it started for the first time today.

I used the 290 jet, center needle position, and 32:1 mix.

After ten minutes of idle (a couple of 1/4 throttle revs), the cylinder was too hot to touch. Is this normal? When revved, it was slow to come back to idle.

Any tips would be appreciated. I'm knew to 2 strokes.

Thanks,

 

[Kgibson]

just idling it will get hot it needs the air movement to cool. Sounds like ur lean on the pilot also, with the slow to come down from idle. You can turn in the air screw a 1/4 turn at a time and see if that helps...that richens up the circuit. Also if u are just running thru heat cycle...run it till it gets hot to the touch and trhen let it cool

 

[Awk08]

just idling it will get hot it needs the air movement to cool. Sounds like ur lean on the pilot also, with the slow to come down from idle. You can turn in the air screw a 1/4 turn at a time and see if that helps...that richens up the circuit. Also if u are just running thru heat cycle...run it till it gets hot to the touch and trhen let it cool

yep !!!!!
turning the airscrew in richens it by adding less air
the main has nothing to do with heat cycles, or a proper 2 tanks of fuel break-in, (which nobody does)
no wide open throttle till them 4-5 heat cycles are done, then just take it easy for a few hours, no sustained wot's
then you'll have to plug chop that main to see what the plug is telling you... rich or lean, and one run for the test wont fry it

anything over a 270/280 should keep you in the safe zone, then plug chop to fine tune

 

[Rubbersalt]

break in procedures are 1 of the areas i am most crucial. I do the same for forged and cast pistons. Forged just needs to be heated up slower.

32:1 premix(NEVER USE OIL INJECTION FOR BREAK IN)
I prefer maxima 927, yamalube 2r, or klots for breakin and riding. Good quality oils break things in slower and more evenly.

My personal procedure;
Run bike for 10 minutes, let cool off for 30minutes
run bike for 10 minutes, let cool off for 20 minutes
***next part you vary the throttle as you ride, do not let it be constant.***
RIDE bike for 15-20 minutes no more than 1/4 thorttle, let cool off - 10 minutes
Ride bike for 15-20 minutes, no more than 1/2 throttle, let cool off - 10 minutes
ride bike for 20-30 minutes, no more than 3/4 throttle, let cool off -10 minutes
ride bike for 20-30 minutes, use full throttle, let cool off
Ride bike as normal. Suggest just taking it east for the first couple hours or so.

If you have a wiseco, this is very critical to break the piston in. Wiseco - aka seize-co. They love to expand all funky and stick rings when heated up fast. Cast pistons are more forgiving but i feel they should all be heated up slowly.

Just for a quick question, have your ports been chamfered? A good number of people don't know this needs to be done after a fresh bore. Sharp/hard edges need to be removed the the ports, otherwise rings can catch them and break things.

 

[Zwiser]

all i did was do 2 heat cycles and then ride easy on different throttle positions