Have a 98 merc efi and the primer ball keeps collapsing when I am running near full throttle for an extended period of time. When this happens the motor acts as if it runs out of gas. let the boat sit for a few, the primer ball returns back to normal and the engine runs fine. The ball seems to be in good shape and operates properly when squeezed. The boat is a 98 ranger R81 sport, my thought is venting but I cant seem to find one on the boat, even though I understand there has to be one for gas to flow properly. I left a similar post on the ranger site with no response. Any help would be appreciated, thanks.