I have a 80's model 115 Johnson with manual shifting. I have all the power I need in forward, but my reverse is weak. The engine shifts easly into reverse but will not reve (speed) up. <br />What should I look for? Does my shift or throttle linkage need adjusting?<br />I did a search the last few nights but did not find anyone with a similar problem. <br /><br />Thanks In advance.