M/C 165 hp acting up

Goathorns

Active Member
I'm not quite sure what is wrong with it lately, or which or what to fix first.
While backing up a couple times when pulling my prawn traps, it seemed like I got water up the exhaust and onto the plugs. There was milky oil and a hi level of it. I changed the spark plugs, the plugs were wet, and the water evaporated from the engine oil by operating without the filler cap, pulled the tube from valve cover to carb, and dipstick out.
Today however, the engine was fine in the morning, but in the afternoon, I operated the boat a longer distance than I have for a week, and after going 10 miles, it started missing and popping, losing power and barely made it back to the marina before it died.
The manifold is 5 years old, a chinese one by HGE.
The electronic ignition module by Pertronics is probably 6 years old, I would have to check that bill. This is the 2nd module. the first one died with similar, but not exactly, performance issues, after lasting 10 years. (it would heat up after 5-6 miles and not perfrom at all after that)
The water pump in the leg is not suppling enough cold water. I removed the hose today and you can put your thumb over the hose and block the flow completely, doesn't turn into a spray nozzle. It should if it was new.
I know that I have to pull the boat for bottom paint, zincs and lubrication, but was hoping to make it until late June not mid May.
I don't want to ruin my engine, I know a bad manifold can wreck your valves, and water in a cylinder doesn't compress, often breaks timing gears into scrap metal.
Any thoughts or advice?
 
I can think of a couple of things here. There is supposed to be a flapper valve in the down pipe which is to prevent water coming back towards the engine from the exhaust. Do you have a closed cooling system? If you are running saltwater to cool your manifold, there is some chance that it has rusted out, which could result in water getting directly to your intake. As far as your impeller in the leg, your entire cooling system relies on it's flow. If it needs replacing, it needs replacing. Sounds like you need to put on your mechanics hat and roll up your sleeves.
 
Back
Top