1) Avoid using fuels containing ethanol as the alcohol content can and does cause internal corrosion, particularly in relation to bikes which are used infrequently.
2) Trials bikes should be run on 100:1 mix for watercooled, and 80:1 air cooled. Oil used should be fully synthetic PREMIX ONLY, and mixing should be carried out using a syringe and measuring jug to be certain the ratios are correct.
3) On bikes which have been run using excessive amounts of oil (50:1 or more), the exhaust system will be completely clogged, and in most cases the rings will be gummed up. These bikes will run far better after exhausts have been properly serviced, and piston rings replaced.
4) High octane race fuels are not required for low revving low compression trials motors, and the slower burn of these fuels will often mean reduced throttle response, in comparison to a lower octane non ethanol fuel.
5) If E fuel is all that you can get, then expect to renew main bearings and con-rod bearings much more often, as internal corrosion caused by E fuel will greatly increase the chances of premature wear.