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kirkallen143 · 04-19-2018, 04:02 PM

Couldn't help but jump in...
I'm staying with the stock carburetor, also. I just got through drilling out my pilot to 0.018" (#77 drill bit), and the stock pilot dia. seemed a lot smaller (do not know how small the K40A is actually, that was the smallest bit I had).

Funny, I have not even started the engine yet (still assembling), but from research on here, I am trying to get ahead for a properly running engine. To start, I drilled the main jet to 0.042" (same orifice dia. as a keihin 110 jet), shimmed needle w/ two washers, will do the air box mod w/ KN filter, removed catalytic converter, and mod'd stock muffler (extra holes in baffle plates, includes grinding the inside header weld).

Here at sea level in Texas, say on 200cc to 400cc single cylinder engines (non-racing) I've had good luck on drilled pilot sizes varying between 0.018" to 0.022", and the usual 1 to 2 turns out on the mixture screw (depending on temps/humidity).

We'll see how it goes, but I'll start another thread about my settings at a later date (hopefully soon)...

Kirk
ps.(forgot to note I have the 2018 Hawk 250)

04-19-2018, 04:02 PM	#11
kirkallen143 Join Date: May 2015 Posts: 84	Couldn't help but jump in... I'm staying with the stock carburetor, also. I just got through drilling out my pilot to 0.018" (#77 drill bit), and the stock pilot dia. seemed a lot smaller (do not know how small the K40A is actually, that was the smallest bit I had). Funny, I have not even started the engine yet (still assembling), but from research on here, I am trying to get ahead for a properly running engine. To start, I drilled the main jet to 0.042" (same orifice dia. as a keihin 110 jet), shimmed needle w/ two washers, will do the air box mod w/ KN filter, removed catalytic converter, and mod'd stock muffler (extra holes in baffle plates, includes grinding the inside header weld). Here at sea level in Texas, say on 200cc to 400cc single cylinder engines (non-racing) I've had good luck on drilled pilot sizes varying between 0.018" to 0.022", and the usual 1 to 2 turns out on the mixture screw (depending on temps/humidity). We'll see how it goes, but I'll start another thread about my settings at a later date (hopefully soon)... Kirk ps.(forgot to note I have the 2018 Hawk 250)
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