"i have a '98(i think) merc 40, not tiller, and whenever i'm running at more than 1\4 throttle i have to hold it where i want it. a few seconds after i let it go it eases it's way back to around 1\4 throttle. is there a way i can adjust or tighten something so that this won't happen and i can just set it and not hold it open?"