How much to bore?

[z40021]

I have a 03 z400 and want to bore it to a 440 to be more competitive. I was wondering how much it costs to bore the cylinder out.

[Iliketogofast]

You can't just bore the sleeve and install a new piston. You have to bore the cylinder and get a new sleeve and piston. It comes in a kit, and you generally have to send the motor to the shop you bought it from for boring and sleeve installation.

That would be a great time to get some other head mods done though, such as porting and polishing, decking or a three angle valve job... Just send it all in at once as a tame Z400 and get a screamer back in the mail a couple weeks later.

[hotrodbelair]

i had a local machine shop do my 440 it was 175 and magic racing does it for 176. so i think most places will do it for around that price range.

[GPracer2500]

The Z400 has a plated cylinder (similar to a Nikasil coating). There is not sleeve. So, the options are to either bore the stock cylinder and have it replated; forgo the coating and have a sleeve installed; or get an entirely new cylinder.

Check out LA Sleave for the sleaving route or Athena for the new cylinder route. Those are just two companies though--there are others.

Here's the Athena 435 kit. The nice thing is that it's essentially a bolt on kit and you still have your stock cylinder if you ever wanted to go back to the stock bore:

http://dtdyno.com/images/athena435bigbore.jpg


I'm guessing any one of the three options is going to cost you between $500 and $800 (new or redone cylinder, piston, gaskets, etc.).

[z40021]

I want to have my motor done by yoshimura but cant aford it so I might get it bored out if it is only 175ish and then you can get a jt 440 kit off ebay for 150. And to you Iliketogofast I knew their was more i just didnt know how much it costed to bore out the cylinder.

[z40021]

Thanks

[Iliketogofast]

Well just to bore the cylinder only cost me $45, but mine was just a rebuild on the R.

[400exrules]

a friend of mine has a z400 and a dvx 400(drag bikes), both bored to 440 with 13.5:1 pistons in them..........ya, they haul........

[tallguyturbo]

Originally posted by hotrodbelair
i had a local machine shop do my 440 it was 175 and magic racing does it for 176. so i think most places will do it for around that price range.

What all did that include? I'm considering goin 440 in the next couple months and need to start pricing it all out.

[hotrodbelair]

Originally posted by tallguyturbo
What all did that include? I'm considering goin 440 in the next couple months and need to start pricing it all out.

i paid 220 for the sleeve and piston then 175 to instal the sleeve.

[DieselBoy]

I paid $80 at a professional engine builder shop. Bored, honed, and bead blasted for $80 OTD. He even took the head studs out, and milled everything...

you know whats funny? a 400ex sleeve is only $16, but to have it installed gets you up to 300 dollars. i priced it...

[400exrider707]

Originally posted by DieselBoy
I paid $80 at a professional engine builder shop. Bored, honed, and bead blasted for $80 OTD. He even took the head studs out, and milled everything...

you know whats funny? a 400ex sleeve is only $16, but to have it installed gets you up to 300 dollars. i priced it...

That price sounds about right to me, its the sleeving that gets the dollar signs going... :ermm:

[z40021]

does 120 soundabout right to get the cylinder bored and sleeve pressed in cause thats what someone said they paid and they had it bored to 95.5mm/450.