What sort of contact breaker drive/distributor housing is fitted to your Bullet? You might do better with the type fitted to late export 500 Bullets which has the shaft running in proper bearings, the one shown in your photo seems to be the older type.
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If many German Bulleteers are using the OKO successfully and yours is still running rich, I can't imagine all those Germans wanting to stop and clean their spark plugs every 50km,
so you must still be doing something differently from them - pilot air screw adjustment, perhaps? Needle position?
Forgive what I hope is a silly question, but are you running with the cold-start plunger wide open, or at least not fully closed? Check the lever or plunger cable is properly adjusted, and that the thing shuts off properly once you have the engine running.
To make that 19T sprocket worthwhile you need a seriously tuned engine, I would suggest a high compression 87mm piston, a tuned cylinder head and fancy cams, not just a less restrictive carb and silencer, because a stock 500 Indian Bullet engine is still in a very low state of tune. Tuning up the engine then places extra stress on the bottom end, so with that tuning package I would also want a steel con-rod and roller big-end.
You might be interested to know, however, that in the 1990s a UK motorcycle dealer was racing 500 Indian Bullets, still with the standard cams and 6.5:1 piston. They fitted the smaller bore exhaust pipes off the 350 models and LOWERED to gearing slightly from the factory 17T gearbox sprocket to a 16T, to help the engines rev more freely. Maybe your efforts should be heading in this direction? Otherwise enjoy playing tunes on your gearbox. I know the Netherlands are not noted for mountains, but the wind is definitely a thing over there!
Photo: fineartamerica.com
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