350x ??

[YAMAHA_Jim]

WHat is the biggest cc you can bore a 350x. Theres a flat track blaster that races here w/ a 350x motor in it.Someone said it was a 385X,,,is this possible?? This blaster hauls major Arse. He is in a different class so i havent raced against him.

[200xman]

I think Powroll used to go up to something around 390-400. Don't know if they still make anything that big.

[350Xccelerator]

i think the biggest kit powroll has is 430.

[3WheelsForever]

If you want to go bigger than 430 you can talk to LA Sleeve, they make a kit for the 350x. The sleeve and piston that comes with it makes the 350x to a total of 452cc!

[hondatrikesrule22]

I bet that costs a pretty penny :shock: .

[Tyler 54]

LOL I seen a 460!!! yes 460 kit on ebay a while back.It went for over $700 :-D

[MR ATC]

with machine work to the lower cases ( for sleeve clearance) a 350X can be built up to 500cc. the crank is more then capable to withstand the added displacement.

[84250r]

with machine work to the lower cases ( for sleeve clearance) a 350X can be built up to 500cc. the crank is more then capable to withstand the added displacement.

WTF,,,blink blink,are my eyes fooling me. Should i say welcome back Mr Atc...... :shock:

[Troll 2]

Here's a thread that say's TC Racing makes 350X engines all the way up to 550's converted by him..$$$$$$ but very fast.
Link=> http://forums.atvconnection.com/messageview.cfm/catid/15/threadid/362144.cfm

[trikerider2oo7]

550?!?!?!? Hayseuss! That thing would fly!!

[TimSr]

From my information, max overbore on a 350x is 1mm which would be 359cc. So in answer to your question, you cannot bore a 350x out to a 385, however several big bore kits were offered for it at one time, and he had to have installed one if his 385 is accurrate.

[YAMAHA_Jim]

Thanx for the info.I'm not to familiar with 350x motors and big bore kits.

[wilkin250r]

There are lots of answers and some seem to be contradictory.

To clarify, there are different ways of increasing the bore on an engine.

I don't know the 350X in particular, but I know engine modification in general. One person mentioned that max overbore is 1mm, which is a total of 359cc. This would be the maximum overbore on the STOCK cylinder sleeve.

If you want to go beyond 359cc, you would need to install a new sleeve. This isn't terribly difficult. You bring it to a shop, and they press out the old sleeve, bore the cylinder a little, and press in a new sleeve. This will probably get you up to about 400cc.

To go bigger, you need an even BIGGER sleeve. This gets difficult, because the bottom end can only accept a certain size. So, in order to go bigger, you need to press a bigger sleeve into the cylinder, and ALSO you need to machine the cases on the bottom end to accept the bigger sleeve. This is no small task. If you send it to a shop, it is usually at least $500 in labor just to split the cases to machine them. However, with this method, you can increase the bore to over 500cc.