Scooterotica

I have a malossi 221 engine at the mo in my 152L2 and I am not too happy with it really. It's low on torque, and 4th gear is a problem. The age old: thrash the nuts off it in 3rd, keep your head down and pray there are no inclines coming on the horizon.
I had it dynoed at Diablo and it makes 18bhp, which is a bit disappointing, but as Alan pointed out, with less than 12 bhp at around 4500 rpm, it's not going to pull the gearing, even with a T5 4th gear. An age old malossi trait.

I had a ride on Alan's Polini 210 and it was much better. Power lower down the rev range, with lots more torque to boot.

I should have listened to Alan in the first place......

Anyway, I have decided to go Polini, but time is tight, and I am not prepared to miss the summer waiting for a scooter shop to swap it for me. So I will do it myself, probably.

What I want to know is, with my current set-up. Harry Barlow put the packer at the top of the barrel. Will this work with the Polini too?

Also will the head I already have work with the Polini too?

Is there much difference in the crank case porting between a malossi and a Polini? Will I need to port the cases again?

Any advice would be much appreciated.

Ps anyone want to buy a Malossi kit?

Wax watch this space! my polini 220's gone on dyno(s/erotica)friday, setup and dyno graph will follow.....

Super. I would like to see that..........................

Hi. Polini piston crown is a different radius than the malossi so to do a proper job you need a different head. A specific SIP head is available for 60mm stroke that eliminates the need for a head packer.
Transfer ports in crankcase will be near enough to make no difference.

What exhaust are you using. Maybe a gruntier pipe will help at the expense of top end. Rotary or Reed?

SF

I have a SIP Road in my Malossi 221 (1 mm base gasket, 0,5 head gasket (aprox 125/185), MMW head, RD reeds, all ported, M Tech, Keihin PWK 35 AS, short 4 gear, etc) and it is plenty of power in all RPM range. Top speed is some were arround 135 k/h (no way of measuring) and it can go 120 k/h every were.

Sip Road plus new set of rings = new engine.

Kool. I am using a JL left hander and its rotary induction via a 28mm carb. I went for a blast last night and it seems much better than I remember from last time? Tucking my head down at 60 hot me through and into the power again. It's only done about 70 miles, so maybe it's loosened up a bit? Or is about seize due to an air leak! I did a plug chop though and it was brown? The temp on the sip speedo was about 55 degrees too.

Is there something wrong with it? The Germans are getting upper 30s from Malossi 221 top ends.
18 seems remarkably low, considering what it is.

(not taking the pi ss)

I don't want nothing that crazy! I have a 34bhp TS1 for that. I Just want a reliable scooter that pulls 4th gear and doesn't need filling up every 20 miles.

Perhaps the new malossi kit will sort out the peaky problems? Has anyone dynoed one yet?

Al did my polini 220cc it still uses the standard carb,auto lube and SiP road exhaust.
I haven't got the dyno sheets but Al said 19bhp & loads of torque, also getting 12 MPL
It made a bit more power using the polini induction but did 7/8 MPL

Sounds good to me Train Driver