Looks very lean, What do you think?!

Jonny Appleseed /

Just pulled the head off my new A55 Airsal to see how the piston+cylinder were fairing, and boy am I happy I did. I attached a couple pictures of what it looked like. I ran my finger over the cylinder wall and it was bone dry. Luckily, there doesn't appear to be any significant damage to either the cylinder or piston.

I was running a 74 jet in my 14mm PHVA, have since upjetted to a 78. Do you guys think that will be a significant enough upjet or should i go up a size or two more?

Also, in the picture of the head you'll see there's a little knick in the squish-band region... It came like this but i didn't think much of it until I started reading more and more about squish in Bell's tuners handbook. do you think it's significant enough to cause any major performance issues?

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Re: Looks very lean, What do you think?!

How much oil you are premixing, the cylinder seems to have a little scuffing. The nick in the head wont matter much, knock down any high spots and the low spot will just get filled with carbon.

Re: Looks very lean, What do you think?!

Jonny Appleseed /

premixing 2%.

Re: Looks very lean, What do you think?!

i agree take down the high spot and it shouldn't matter much also if this is a new engine i was told to run a thicker mix my buddy (a bike mechanic) told me to run 2 tanks of 25:1 for break in and then start leaning my mix though there are probly people with alot more knowledge than myself overall doesn't look to shabby though would hop on some oil though

Re: Looks very lean, What do you think?!

50:1 is fine if you ditched your oil injector.

What does your plug look like now?

Re: Looks very lean, What do you think?!

Jonny Appleseed /

well, the plug that was in it when i was running it with the 74 jet was light with a little bit of erosion on the ground electrode. Since i upjetted to a 78, the plug is nice and dark although i haven't done a WOT plug chop yet.

Re: Looks very lean, What do you think?!

Jonny Appleseed /

what im most nervous about is the cylinder wall scuffing... is that normal...? it still feels completely smooth.

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