I have an Atwood primer bulb that came with my boat that is rock hard and almost un-squeezable when it's less than 50-60 degrees. On my Nissan kicker motor the primer bulb is soft, easy to squeeze, and primes in just a few squeezes at any temperature. I'm pretty sure it's an OEM bulb that came with the motor. Can anyone recommend a good supple 3/8 bulb for my main motor (60 HP Johnson).