ESE's works engine tuner

[quallman1234]

I haven't seen a mention of Elf 976? I know you can still get that in NZ . Its recommended next to A747 in the RS125 manual, its what i used to use on my RS125, never had a issue!
Wasn't cheap though!

[Frits Overmars]

The RSA 125 uses roller bearing for crank mains. What is the advantage of rollers over ball?

Roller bearings can take higher loads, but that is not the main reason. When fitted correctly the Aprilia bearings allow for 0,4 mm of axial play. Any less costs power.
You can't do that with ball bearings (unless you use a sloppy fit on the shafts, like many kart tuners used to do).

[wobbly]

976 is a full synthetic just like Motul 800,so is OK for unleaded fuel ( as they were designed for ) when run rich to prevent breaking down the oil
when it overheats.
I did hours of dyno oil testing for a customer using 909 and 976 in a KT100 to establish the best type and ratio.
As soon as you really wind in the needles the superior lubrication of the castor base made more power the hotter the egt got.
The 976 started to show marks on the skirts and lost power over around 620* in the header.

[quallman1234]

976 is a full synthetic just like Motul 800,so is OK for unleaded fuel ( as they were designed for ) when run rich to prevent breaking down the oil
when it overheats.
I did hours of dyno oil testing for a customer using 909 and 976 in a KT100 to establish the best type and ratio.
As soon as you really wind in the needles the superior lubrication of the castor base made more power the hotter the egt got.
The 976 started to show marks on the skirts and lost power over around 620* in the header.

Thanks for that, was curious

Majority of 125GP bikes in NZ are running on the wrong oil in that case .

[jasonu]

Majority of 125GP bikes in NZ are running on the wrong oil in that case .

Probably because it is cheaper.... not that you could ever accuse a Kiwi motorcycle racer of skimping.

[quallman1234]

Probably because it is cheaper.... not that you could ever accuse a Kiwi motorcycle racer of skimping.

Its not that cheap!

You learn quickly that you should never skimp out on the RS125's Recommended Servicing life of a part (Or any two strokes for that matter)
It ends up costing you more otherwise! Obviously if you had the knowledge and experience of Wobbly it would be different! But i'm just a newb!
I am one of the lucky few who just followed the book, and never ever once had a issue. Apart from the bike keep falling over but i think that was more the rider .

[Drew]

Apart from the bike keep falling over but i think that was more the rider .

It's an inherent design fault with bikes. Get a sidecar!

[F5 Dave]

how 'bout a nice sensible Austin Allegro. Suit you Drew.

[peewee]

The high B port KZ2 engine won the Nationals here in 2013 and was insanely fast down the shute.
But this year I went thru all the testing again with the newest iteration of the TM - KZ10 .
This had the casting changed by the factory that allowed much bigger Aux Ex ports, and proved in the final analysis to generate more bottom end than I could drag out of the older engine, no matter what.
It won the title again this year, proving to be faster in outright power terms than the very best World Cup winning engines by SavTech from Europe, due in part to the extra
off corner response - also down to the perfect jetting combo on the day.
A super proud day for me and the team, making the pass for the lead at the end of the main straight with 3 to go after getting a way faster straight entry speed and carrying it in the draft.

i can see why someone would use a high B. allows the aux to be just that much bigger by bringing the floor down alittle more. but some engines cant have the aux floor right on top of the A like aprillia because the side piston skirt is cut to high so the aux floor needs to be kept alittle higher or you get a shortcircuit. on a situation like this do you think the high B would still work better or is its only benefit to allow the aux floor to sit right on top of A ? basically what im wondering is does a high B only have the benefit on letting the aux floor be very close to the top of A (assuming the piston design will allow it without creating a shortcut) or does a high B also have some kind of scaveging benefit also ?

[wobbly]

No - the high B gives more total STA to the transfers, as in a well designed setup it is alot wider than any A port.
So you have the B and C ports combining to give a better total STA than is possible with a normal small A and progressively lower B and C ports.
But its always a compromise, it makes no sense to run a high B port with no powervalve, as this scavenging regime favours top end at the expense of below
pipe power.
As I detailed before I could, and did, make a very good attempt at matching the high A port setup in a KZ2 with the big B port situation -
but at the end of the day we needed the high A port to get natural drive off the bottom when passing in traffic.
But this was helped some by the factory catching up on the usual 3 year lag in technology when comparing GP125 with KZ2 and allowing me to grind really big Aux port top edges
to gain sufficient blowdown to match the rocket ship big B port engine I did the year before.

[jasonu]

Its not that cheap!

I said cheapER.
NZers are notorious skimpers.

[Drew]

I said cheapER.
NZers are notorious skimpers.

Naaaaaah. Second hand tyres were fine on a full power superbike.

[peewee]

what you guys think ? engmod is suggesting the reeds open 2mm more. i managed to get 1.5 more . hard to say if its going to work but theres only one way to find out

[wobbly]

What is limiting the tip lift ?
Is it that the plate wont fit when any higher into the reed box.
Could you could just add another 0.5mm piece of reed strip under the plate - but general rule is to keep lift under 0.3* reed free length = 27mm for 9mm lift.

[peewee]

nothing is limiting the lift. i had some spare stoppers around and cut the fingers off then used the end strip under the cage stoppers. didnt think of it but ya i can cut a strip from some old reeds and put that under the stopper also. i wonder if the pressure differentials will actually open the petals this much now ?