MJA
Key Veteran
Location: Cumbria-UK
| Ideally you'd be better changeing the pinion gear to a 15tooth or 14 tooth.The 15 tooth gives 8:1 ratio,the 14 is around 8.45 to 8.5 i think,can't really remember exactly.
When moving down the pinion sizes you will need to also use thinner engine mount shims to keep the engine in line ,than shims used with 16 tooth.
If you search the Runryder Robbe forum you should find enough info there about shim thicknesses
MPII is quite good on the 91ST and hassle free to fit.Doesn't need that much of the canopy cutting away. Hatori mufflers would likely need more canopy cutting forward of the exhaust opening.
If you were useing the Hatori 700 with the Webra 91,it's supposed to work quite well with the 91ST according to the MHW test that Mike Billington did in March2004 on that engine ie in as much as it gave very good torque / HP figures
You'd need to get another manifold though or drill the holes closer together to match the 91ST and make a thin blanking plate maybe.
Whatever exhaust you fit ,be careful about how close it runs to the tank where it sticks through the frame openings
,especially if it's the original Millenium setup rather than the Dyna-X.YS uses full pressurised tank setup and under pressure the tank can swell outwards quite a bit
Martin |
