LCGB Forums

Going to be fitting an Avanti ex box and 17t front sprocket at weekend(currently on Bgm v.2 and 16t).
Will I need to up my main jet?
Im running a 28mm PHBH with 118 main jet
All info appreciated.
Cheers

Plug chops are the best indicator of that but you could go up a couple of sizes to be safe and work your way back down.

Rich Oswald wrote:Plug chops are the best indicator of that but you could go uo a couple of sizes to be safe and work your way back down.

Nice 1,thank you

what top end have you got on ? Gear box ? Crownwheeel ?

Why increase the front sprocket size ? whats the intended result ?

You are potentially changing 3 things all at the same time - which adds a degree of complication if the results arent what you expect

bookertmgs1 wrote:what top end have you got on ? Gear box ? Crownwheeel ?

Why increase the front sprocket size ? whats the intended result ?

You are potentially changing 3 things all at the same time - which adds a degree of complication if the results arent what you expect

+1

Rich Oswald wrote:Plug chops are the best indicator of that but you could go uo a couple of sizes to be safe and work your way back down.

+1

Thanks for the replies.
Going off another thread about raising my top speed a little(and wanting a new exhaust) Im changing to an ex box,going to a 17t sprocket which should give me the extra mph required(currently 62gps).At the moment its screaming at top end.l,so going to a 17t would help to reduce that too?
Any and all advice greatly accepted.Thank you

bookertmgs1 wrote:what top end have you got on ? Gear box ? Crownwheeel ?

Why increase the front sprocket size ? whats the intended result ?

You are potentially changing 3 things all at the same time - which adds a degree of complication if the results arent what you expect

I have an RT195 and 46t crownwheel with pacemaker box.

I would try the exhaust first before changing anything else you will know then if you need to alter the gearing

Micky67keane wrote:

bookertmgs1 wrote:what top end have you got on ? Gear box ? Crownwheeel ?

Why increase the front sprocket size ? whats the intended result ?

You are potentially changing 3 things all at the same time - which adds a degree of complication if the results arent what you expect

I have an RT195 and 46t crownwheel with pacemaker box.

Ok - with the Pacemaker gear box & 17T would make it very similar to LI150 & 16T which should suit the kit.

Dont forget you are likely to need a new chain too.

On a standard RT Kit you should expect another 5mph flat out - but nothing revolutionary

Thanks for the replies,should have changed this by now but hopefully THIS weekend!

Only just got round to doing this.Seems to pull alot better now,2nd and 3rd have a more useful range and 4th isn't screaming it's head off.
67mph gps speed which is liveable(for now..)
Thanks for all replies/advice,gratefully recieved.Cheers,Mick