boring out 300

[foxracing2218]

how big do you think i could make the cylinder head without it cracking. its a 98 i dont think its ever been honed before.

[bwamos]

You mean cylinder bore?

I forget exactly how high you can go on the stock sleeve but I beleive you can at least go up to a 296cc (+2mm / +.080 overbore). I beleive 313cc (+4mm / +.160) is the highest reccomended bore on the stock sleeve. I could be wrong though.

330's (+6mm / +.240")and 350's (+8mm / +.315") are common big bores. But, for these you really need a new big bore sleeve. I've heard of people going up to 400cc's but, I have not personaly seen one in person. Couldn't tell you how thin the cylinder walls would be, or how reliable they are.

[bradley300]

ive seen up to a 380 that was just abore (i think FST does it)

my 300 was a 350 big bore that gt thunder did

[honda250xrider]

max i would go would be .80 over bore on stock sleeve, you can go much higher on aftermarket, i would not bore unless you plan really bore it out, .80 is not much and will not net u much hp what will is the hc piston. The ports on the 300 are very very small.

[honda300EXtreme]

well, to my knoledge .120 is the largest you can on on a stock cylinder which comes out at 305cc's


with these you will see some gain, but not alot

there are aftermarket sleeves common ones being 313, 330, 345, 350, and a 380 or 385 or 390 made by fst, anything over a 330 you should invest in a hd rod, and it will require case boring


but you will see the real gains out of a cam, hc piston, porting, carb, and gearing

[honda8&3]

Four Stroke Tech is an awesome company. Love how they actually make stuff for the 300. Most companies make very little.

[TRX-330]

i only went 40 over with stock cylinder i plan to go 389 prolly next winter. or else im gunna get a 350x engine and put it in.