i have a '96 9.9hp Mercury 2-stroke outboard that i use to push my 26', 5700lb sailboat in and out of the marina. 2-stroke outboards normally shoot all the exhaust out through the prop, however, when the prop isn't sucking enough, there are a pair of exhaust relief ports that are above the normal waterline, to allow the exhaust to exit when there is back-pressure.<br /><br />However, i have two phenomenon that cannot be avoided. <br />1. my boat will only go 6kt, and that's not enough to suck out all the exhaust through the prop.<br />2. the bow-wave and stern-wave grow as the boat gets up to speed and starts to cover up the two relief exhaust ports. This only happens when the boat is moving, at a stand-still, the waterline is low enough to allow the exhaust ports to relieve the back-pressure<br /><br />So I need help in "relocating" the relief ports higher, out of the water (really, the waterline when at speed). Does anybody know the OD of the two ports? Does anybody have a ready-made solution? Does Mercury sell something?<br /><br />Thanks a ton!<br />-mrgnstrn
