420_Big_Bore

Sorted out the problem, it was the rubber gromit on the boost bottle. The old one was split and was leaking air in, so replaced and running perfect! Thanks for your help.

Carb boots are fine, before i pulled it down it was running perfect, but ill check the jets.

Hi guys not sure where to post this but i really need help. I just got my windows in my pistons ported bigger and built the motor back together, but i just started it and its revving really high and only on 1 cylinder. When i push the choke down then it stops. Can anyone help? Thanks!

I was planning on keeping the cast for now until i do go bigger bore or unless these fail. Just wanted some opinions on both sides, and to see if these are ok for now. But looks like my next set will be forged. Thanks for all help.

Cheers. Just needed an opinion. Later on i will get forged when i go to stroker.

Hey guys, i wont go into whole story just cut it down to this. I got a set of Pro-X 68mm cast pistons in my shee. Just wondering will forged pistons make that much difference? Seeing as im not doing any further mods at the moment i was wondering would i be wasting money on a new set of forged pistons when i already have new casts in? Cheers

I've just been told that wiseco dont make 68mm pistons for stock cranks, only stroker cranks.??

Does anybody know where i may be able to purchase some 68mm Wiseco Pistons for a big bore? Ps: I live in Australia.

Ok thanks heaps for your help i will do a plug test this week end and let you know how it went. And if my plugs were black would i need to go down in jet size? Or could it be too much oil in the fuel?

the BR8ES had oil on, but i havent done a recent plug chop. What do i need to do if it is oily? and what do i do if its black but dry?

Ok will do that this week end and let you know. By the way i am using NGK BR8ES plugs, not sure if they are similar to you guys?? Do you run hot or cold plugs?

Nah i am using the 34mm carbs and yes the jetting is definitely too small (for drag pipes), i was just wondering what size i would need to jump up to from 330? And anything else i would need to change?

Yeh 330's were for the setup i had before i got the drag pipes. Ok so if my plugs are black oily / or black dry what would i need to do? I've never heard plugs of being brown?

Well i had a stage 2 port job and then i got a 409cc Big Bore Kit. I live in Australia and somebody in Tasmania done the work for me and said to run 330's (with the bigbore kit and pro's). He said he didnt know much about drag pipes so thats why im askin you guys. Im guessing a set of wisecos will make a bg difference as well? Wow 400's, thats a big jump. Yeh he did have a site, grandriverracing.com but i cant find it anymore?

Yeh i realise that now, but i couldnt find any 68mm wiseco's around. Might have to ask round. Well with my pro's and the setup i got, the mechanic told me to run with 330 mains.