problem with my motor it is a 60hp 1988 oil injected VRO and i have a problem it is starting sometimes hard it starts only when chocke is on even when warm weather is out then i have to let it rev up and then take choke off it seems to be ok then reverse it it is ok then shifting back into forward it stalls then rev it up again with choke then put in forward it is ok at low speeds but then when i leave at full throttle for a few seconds it shutts off so what is the prblem?