I have been using this 470 all of last summer, and for the first month of this year, and it has been starting and running fine. I have never had to take it over 3500rpm, but when I tried last week, the engine "bogged down". I re-set the timing, and took it out again, and had no trouble reaching 5000rpm, but almost immediately, a knock developed, and is now there at any speed, and it isn't a random, or irregular knock, it's quite consistent with engine speed.
I have tried retarding the ignition, but to no avail. My knowledge of marine engines is severely limited, but I've owned enough clunker cars to be very suspicious this is a rod bearing. My question is, is a rod bearing likely to have failed quite so quickly? I would have expected a sight knock, getting worse over time, but to have developed over a few minutes doesn't seem kosher. I have tried removing the plug leads one at a time, to see if the knocking diminished, but it does not seem to have any effect. I am on the point of pulling the engine, but would appreciate any opinions before I do.
Thanks
I have tried retarding the ignition, but to no avail. My knowledge of marine engines is severely limited, but I've owned enough clunker cars to be very suspicious this is a rod bearing. My question is, is a rod bearing likely to have failed quite so quickly? I would have expected a sight knock, getting worse over time, but to have developed over a few minutes doesn't seem kosher. I have tried removing the plug leads one at a time, to see if the knocking diminished, but it does not seem to have any effect. I am on the point of pulling the engine, but would appreciate any opinions before I do.
Thanks