View Single Post
Old 07-07-2014, 04:22 PM
Theon Theon is offline
Motorized Bicycle Elite Member
Join Date: Jan 2014
Location: FNQ Australia
Posts: 1,440
Default Re: Dual Suspension 'Roo'

Cheers Guy's,
This motor comes recommended with a 39t sprocket and after giving it a good strapping on a 44t, I'm keen to try it on a 39.
I didn't get the low to mid grunt from this motor that I do from my reed valve motor, however top end is really good, and I feel is better suited to road bike, The Goat has a much lighter frame, Much better brakes and now has a reasonable set of road tyres and a 39t sprocket.
So the plan is to put my new Roo in the Goat, leaving it stock for now, well, we'll see, I am tempted to give the motor a little more compression and have a bit of a play with the transfer ports, but I want to do this motor step by step, so I can see the improvements of each mod, however I am aware that certain mods work best in combination, and I am aware that Dino when building this motor has put a fair bit of development in to getting it to work so well, he has obviously found a good 'balance' of power, reliability, and Cost.
The Twin carbs seem to be working nice, with plenty of throttle in reserve, the motor was doing amazing revs and not even WOT. However a big Walbro is probably what I will have to use due to space restrictions, and maybe wanting to run a muffler where the left side carby is.
It has a strange dual personality, where it is very quiet and a little 'tame' until you get the revs up, Then the 'Turbo' kicks in, the exhaust note changes to a louder and more aggressive note, and takes a fair bit of backing off, to get the motor to 'calm down' again. Dino has obviously 'sacraficed' a little low down to get this motor to run sweetest in the higher revs, I'm not sure that I should mess with it to much. I even like the nice quiet low speed operation, and am putting a fair bit of thought into the exhaust, the Exhaust I built for the Goat was aimed at low to mid, and I will have to try it on the Roo, it may improve my low down, and I can't see how it can hurt my top end over the standard pipe.
I have found a cheap set of reasonable 24" Rims, and have decided this way on my 'Dirt bike', which will get the Phantoms bottom end with the Goats Top end and reeds. I am starting to get a bit of a shopping list for my 'Dirt Bike', and would like to do it right, so may have to take my time with it.
Reply With Quote