No es "sólo" la horquilla, además los "shift dogs" del engranaje de 3ra están redondeados. Son esos tres dientes gordos que encajan dentro del otro engranaje, deben tener el borde cuadrado, cuando se redondean hacen eso, saltan y calzan en la próxima coincidencia con los agujeros.
A unas les pasa en la 2da y a otras en la 3ra, es como si la moto tuviera un hipo cuando la aceleras y todo vuelve a la normalidad 1 decima de segundo despues.
Ayudate con google para leer esto.
"My bike 'skips' in third gear...
...almost like the ignition cuts out momentarily, or some gear is skipping a tooth." You need transmission work. This can happen to any gear, but usually second or third suffers first. People will try to tell you the shock coupling in the transmission is slipping from one position to the next... hogwash. It's not possible. What's happened is that the shift dogs have rounded off and a shift fork is bent. The gear is only engaged by the rounded part of the shift dogs, which let the gear slip off and bear against the fork. That in turn springs the gear back into engagement the next time the dogs line up a fraction of a revolution later. The problem can start with a bent shift fork (from dropping the bike on the shift lever, etc) or with rounded dogs (from too many missed shifts or half-shifts). It can also start from poor initial assembly of the transmission, whereby there was never enough shift dog engagement in a particular gear.
You can be certain you have this problem if the oil is an irridescent gold color when you drain it. The gold is the surface of the shift fork wearing away; normally there is absolutely no wear on the shift forks regardless of mileage. Thin slivers of metal that you find will be from the edges of the shift dogs.
Bottom line is, it needs to be repaired. The problem will get worse and you will damage the shift drum. A good rebuild brings M93 and M94 transmissions nearly to M97 spec. Nearly, meaning that the engagement dogs are straight and five out of six bearings are 'clean.' There will still be one open bearing and an M94 will still have O-rings, but neither difference is significant.
http://www.largiader.com/tech/oiltrans/