More power for GB400 needed

[FilthyLuka]

If the bottom end is the same as an XR600, why not just bolt on the XR600 complete top end? Head, Cylinder, Carbs? You would need to fabricate an exhaust i would imagine (custom chambers in Tamaki).

As far as taking a dremel to the ports goes, dinae do it laddy. Too much you can mess up if its your first time, see if you can find a junk head to practice on. I would just avoid the porting for the time being.

XR top end
Wiseco High Compression Piston
XR Racing Stainless Valves
Titanium Valve Springs and Keepers
Brass Valve Guides
Mikuni TM flatslide Carb (with accelerator pump)
Custom Exhaust headers going to either a big brand racing pipe (Yoshi, Arrow) or full custom exhaust

Personally, I think it would be great fun :-) But if its your only bike, i say leave it stock. The GB's are awesome even without fucking with them.

You could always just bolt in a CR500 Engine

[Brutus]

I had sourced wiseco pistion etc and other internals. But .. think I may just visit Custom chambers and change carb.
I have trouble in the rain, sticky carb, but when I back flush the carb it clears(ie rev the nuts, put hand over air intake to choke it) it works til the next time. I've reconditioned it twice, but to no avail...
Leaving it stock is a good idea but always want more power when your 95kg.

[mark247]

I had sourced wiseco pistion etc and other internals. But .. think I may just visit Custom chambers and change carb.
I have trouble in the rain, sticky carb, but when I back flush the carb it clears(ie rev the nuts, put hand over air intake to choke it) it works til the next time. I've reconditioned it twice, but to no avail...
Leaving it stock is a good idea but always want more power when your 95kg.

I never knew Wiseco made a piston for them... I remember when i had mine it needed new rings and i couldnt find new ones ANYWHERE. I could of got some made i guess but i was on a budget.... so i put second hand ones in because i thought they were alright..... i ended up selling it up... Wish i didnt now, they are such a good looking bike.

[Brutus]

Yeah is was looking at making it a 500cc, after being told the 400 is a sleved 500, but I don't think this is quite correct.
I like it for the forgiveness it has especially with metzlers(?) but the old dunlop arrowmax is certainly a great tire for the GB. Hows the NC30?
i borrowing a 91 cbr 250rr at present and it is a bundle of laughs, think I'm rossi, well sounds like it at 18 grand. redlines at 19 but thats heinous!

[mark247]

Yeah is was looking at making it a 500cc, after being told the 400 is a sleved 500, but I don't think this is quite correct.
I like it for the forgiveness it has especially with metzlers(?) but the old dunlop arrowmax is certainly a great tire for the GB. Hows the NC30?
i borrowing a 91 cbr 250rr at present and it is a bundle of laughs, think I'm rossi, well sounds like it at 18 grand. redlines at 19 but thats heinous!

If you like the old GB400 you will like the NC30. It's just as much fun in the twisties only it actually has a thing called power.... haha. but in saying that my old GB400 was totally awesome for what it was, a thumper.

[koba]

Yeah is was looking at making it a 500cc, after being told the 400 is a sleved 500, but I don't think this is quite correct.
I like it for the forgiveness it has especially with metzlers(?) but the old dunlop arrowmax is certainly a great tire for the GB. Hows the NC30?
i borrowing a 91 cbr 250rr at present and it is a bundle of laughs, think I'm rossi, well sounds like it at 18 grand. redlines at 19 but thats heinous!

Entirely possible, many bikes have a 400cc jap version, rg400 with 45 horsepower is one example!

check this out for some related engrish!
Engrish GB specs.