Merc 60HP runs rough

psatushek · 03 October 2012, 00:13

A week ago my 1996 2 stroke 60HP Mercury bogged down at full throttle. I took it out again yesterday and the engine ran rough shortly after launch. No power at high throttle and seemed to vibrate more than usual. RPM's would increase when turning right, but not when going straight or turning left.

After about 30 minutes the engine started to run normally. It didn't bog down at full throttle and performed normally at other speeds.

Any suggestions on what to check? Water in fuel or problem with carburetor?

matt h · 03 October 2012, 08:33

check fuel from start to finish, fuel pick up in tank .. filters, fuel connector into engine. filter in engine. check fuel pump outlet. check carb bowls for water ingress.

uncle al · 03 October 2012, 19:13

sounds either fuel (most likly) or a loose or dirty electrical connection, I would go fuel first, I would take out the drain plugs (7/16a/f socket size clean rag underneath to catch the fuel and see what if any crap come out of the float bowl,if you want to pm me please do so for a more involved description and things to try.

psatushek · 05 October 2012, 23:33

thanks for the feedback. What I forgot to mention was that the fuel gauge showed about 1/3 when we started, but had dropped to near empty after 30-45 minutes. If I rule out a defective fuel gauge, it looks like we have a fuel leak. I smelled the water that's peeing out of the engine and noticed a trace of fuel, but I'm not sure if that's normal.

Could a leak allow water to enter the fuel system?

If a visual inspection of the system doesn't show a problem, then how do I do a pressure test of the fuel system?

yam man · 06 October 2012, 08:51

If the primer bulb gets hard when primed then there isn't any leaks. Failing that check all your fuel lines and connections boat / engine for visual leaks. Smell of fuel coming out the tell/tell probably the engine running rich ie unburnt fuel out the exhaust

psatushek · 09 October 2012, 18:16

I drained about 8 ounces of fuel and noticed a small amount of water in the bottom of the jar (approx 2 ml).

I don't think I have a fuel system leak because the primer bulb is hard after a few pumps. I've been using non-ethanol fuel. Where could the water have come from? Is some condensation in the tank normal?