Re: 1978 Cross Flow 200 bogging
90lbs is "just fine" on a crossflow V6....this isn't a 35 2-banger. This would be like 100lbs on a V4. As long as they're all fairly close, it shouldn't be the problem.<br />Timing may be an issue I wouldn't over-look...at WOT, it may be loud enough (engine) you can't hear the knock.<br />25P 4-blade may be too much for that 2.5L on an 18ft'r, although it may have nothin to do with your problems, "unless" you've been lugging with that prop, like under 5500 RPM. Bypass valve for extra water flow open at or above plane speed for extra water because the T-stats can't keep up along as for keeping a constant temp, so T-stats could be possible problem at low RPM, and then again, so could idle circuit in fuel system.<br />As mentioned above, have a look at the plugs-take them all out....turn flywheel by hand (clock-wise) and look into each plug-hole with a flashlight and verify piston tops are ok. You can roll the piston on down and see some of the cyl. wall too, that may tell you something if you see alot of verticle streaking.<br />You can set the timing static, but it must be set about 3 degs below Max using that method.