Bonneville America Forums Forums Technical Forums Performance Mods Another Big bore installed!

Heya everyone,
I finished the big bore last Friday, and took it for an easy run around the local streets (it was dark). It felt crisp and powerful but I had to restrain from hitting the throttle too much. So got it home and gave it a good check over, balanced the carbs etc. It actually worked!

Then Saturday morning I saddled up for a decent ride around a trip that had a bit of everything like hills/straights/traffic lights etc. I reached the petrol station at about 30km into the trip and all was still ok so I knew it was time to see how she went. WOW, this bike feels strong and smooth and hardly any dips in power until later in the ride. Thats when it started to get stronger and stronger, I was slowing up then using 1/2 to 3/4 throttle to accelerate and the clutch was slipping at higher revs!!!!

The clutch slip was a bit disapointing because I had to ease up a bit, but that was to be expected. I have the clutch springs on order from brent anyway so i hope they arrive soon! I will run it in progressively over the next 1000km then get the dyno tune to see what it is making for horsepower / torque.

The current set-up is:
904cc Wiseco, Ported head with match ported inlet manifolds, valve grind, freak, D&D pipes, thruxton needles, 42/155 jets, 18t sprocket (a must for this bike).

Good job. You did it yourself I am assuming? Nothing better than hitting the starter the very first time and it jumps to life. Makes your heart go pitter patter don't it?

I rember my first time with the big bore, its like no other.

You changing the clutch plates out or just the springs?

Thanks mate, yes I did the big bore install myself. It sure does give you that sence of achievement once it starts up, especially as this was the first motor that I've ever done any major work on!

I'm only going to change the springs as the clutch (and bike) only has 10000 kilometres on it, hopefully that is all I will need to do.

Nice job. I have the same thing instored in my future

The clutch plates are strong enough to handle the Big Bore kit. All you'll need to change is the clutch springs......Angelis

I'd suggest roughing up the steel clutch plates with sand paper or with a blast in your glass bead cabinet, when you install your new springs.

Hopefully you didn't slip your clutch long enough to "glaze" the friction disks.

Main thing for you to check when doing your spring job is to see if there are blued spots on the steel plates, indicating over heating from slippage. If you find that, get all new steels and frictions - and change the oil.

Congrats on your project!

Hey Runner. Did you buy the BB kit local or from OS? What did the project cost you? cost you? Thinking about spending my tax return on exactly the same!

Hey Brett,
The Wiseco kit cost me Aus$670 from my dealer if I remember correctly. Then you need a few other things such as rotor/tensioner/clutch cover gaskets- ~$30, clutch springs ~$35, valve shims (maybe)~$10 each, oils and filters~$55, and machine work which will cost any where between $280>$600 depending on what you do to your head performance wise.

I did the re-build myself, a shop would have been too expensive. I can do a good deal on that if you want to bring it to Wollongong, send me a PM if your interested.

I have just installed the 904cc kit, K&N filter and open pipes and boy am I impressed!

Wizza
Bendigo Victoria

I just finished installing my jealousy kit.

Stop it y'all your killin me.

Congrats Chris on the install. Good Job! Sounds like you deserve a nice cold keg now.

Outstanding guys. I hope my info was useful to some of you too.
Have a VB on me!

dangit bastards! I'm getting a deposit back on my old duplex I just moved out of and I may just spring for the Wiseco kit (if the girlfriend doesn't notice...).
I found a local machine shop to do some mild headwork too for a reaonsable price. I think they said 75/hour.