At F2 Motorcycles Ltd we still hear from people who have set their tappet gaps according to the factory handbook. They usually complain of lots of noise coming from the right hand side of the engine. So here is the F2 Motorcycles Ltd guide to setting the tappet gap.
The factory handbook instructions require the tappets to be set at top dead centre using marks on the flywheel. This system assumes that the lowest point on the camshaft is machined exactly to correspond to the position it is in when the piston is at top dead centre. A fair assumption, but unfortunately in the case of Ural it is a completely false assumption. The method and settings we use at F2 will work on all Ural 750 OHV engines. The same method but with different settings will work on every 4-stroke engine I have ever come across.
It is so simple.
Start by removing both spark plugs so the engine is easy to turn.
Looking at the rockers, turn the engine over slowly using the kickstart until the inlet valve has opened completely and has just started to close. To be clear this is when the spring you can see on the inlet valve has completely compressed and has just started to return.
Stop the engine at this point and set the exhaust tappet clearance. Always use two feeler gauges. The 0.10 mm feeler should pass through the gap and the larger 0.15 mm should not.
If any adjustments are needed hold the adjuster stationary with one spanner and loosen the locknut with another spanner. Then make your adjustment and retighten the locknut before checking the gap with both feelers.
Turn the engine using the kickstart again, until the exhaust valve has completely closed and has just started to open. To be clear when the spring you can see on the exhaust valve has extended to its longest length and has just started to be compressed.
Stop the engine at this point and set the inlet tappet clearance in the same way as the exhaust was set.
The settings for Ural 750 OHV are between 0.10 mm and 0.15 mm.