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'99 250 saltwater series ox66 stalling/losing power
My second season with the motor and it has run perfectly, until this. It started by losing power - would be running at 4000 and it was like I pulled the throttle back to neutral. It would start and stop like this with the occasional stall.
I replaced the fuel/water separator (full of schmutz), the inline oil filter, the fuel filter that is in the plastic reservior before the VST, have taken apart the VST and cleaned the filter (it was pretty clear) - the gas was clean in the tank itself. This helped the loss of power, but it smoked like hell. I then cleaned the O2 sensor (it wasn't seeing any exhaust at all, LOTS of buildup). The sensor read over 1 volt before cleaning and is in the 0.5 to 0.6 range now and the smoking has been pretty much eliminated. It ran decent in the slip out of gear. Now once under power it almost got on plane before it stalled. Hell of a time getting it started - got towed - seemed like it wasnt' getting fuel. I open the VST back up and found a large number of black granules in the VST filter on the PUMP side of the filter (and there was black sediment on that side of the VS tank. Some think it may be the fuel line rotting from the ethanol, but the first filter is clean. There is one more hose between the filter and the engine. Any ideas?
Could it be the high pressure fuel pump or may the small ones on the side need to be serviced/replaced?
One more detail - I did a compression test before taking it out on the last ride/tow. The port side top chamber initially read 150 PSI, the middle 140 and the rest around 25. I changed out all of the plugs with the specified NGK's as I moved along and re-checked the first 2 again that then showed around 25 PSI. Perhaps I hadn't decompressed the gauge first, but weird nonetheless. I have no idea what pressure it should read other than they should all be withi 10% of each other.
Sorry for being long-winded. I could use some expert advice. Thanks.
I replaced the fuel/water separator (full of schmutz), the inline oil filter, the fuel filter that is in the plastic reservior before the VST, have taken apart the VST and cleaned the filter (it was pretty clear) - the gas was clean in the tank itself. This helped the loss of power, but it smoked like hell. I then cleaned the O2 sensor (it wasn't seeing any exhaust at all, LOTS of buildup). The sensor read over 1 volt before cleaning and is in the 0.5 to 0.6 range now and the smoking has been pretty much eliminated. It ran decent in the slip out of gear. Now once under power it almost got on plane before it stalled. Hell of a time getting it started - got towed - seemed like it wasnt' getting fuel. I open the VST back up and found a large number of black granules in the VST filter on the PUMP side of the filter (and there was black sediment on that side of the VS tank. Some think it may be the fuel line rotting from the ethanol, but the first filter is clean. There is one more hose between the filter and the engine. Any ideas?
Could it be the high pressure fuel pump or may the small ones on the side need to be serviced/replaced?
One more detail - I did a compression test before taking it out on the last ride/tow. The port side top chamber initially read 150 PSI, the middle 140 and the rest around 25. I changed out all of the plugs with the specified NGK's as I moved along and re-checked the first 2 again that then showed around 25 PSI. Perhaps I hadn't decompressed the gauge first, but weird nonetheless. I have no idea what pressure it should read other than they should all be withi 10% of each other.
Sorry for being long-winded. I could use some expert advice. Thanks.
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