Yesterday I was running back to the harbor at high speed with my tiller-operated 2003 NSD40B and 16' inflatable when the alarm sounded and I looked back to see the center light on (may have been flashing) and copious white smoke or probably steam streaming out of the cowling intake at the back. I immediately closed the throttle and after about a minute, the alarm and light went off, and the steaming stopped. I remained in gear at idle, and removed the cowling, but could see nothing amiss - so far as that goes... Sound at idle was smooth and normal, no visible smoke or steam. The telltale stream appeared normal throughout (impeller recently replaced), and the fuel squeeze bulb was firm with gas.
The seas were smooth with no wind and we were making about 1.7 knots, though there is almost always current along there to confound speed determination. The motor would not respond at all to throttle, other than to sound a bit throatier as the throttle was opened. After a few minutes, I tried the key-push idle control, which worked as normal and I bumped it to the highest idle setting, which gave us 2.2 knots or so and we got back home. Those are typical speeds at idle. My impression was that the throttle would not produce those RPMs, though the idle setting did, but I probably didn't test that conclusion carefully enough.
Once on the trailer back home I put the muffs on and let it idle a bit, then tried the throttle and it appeared to rev fine and quickly, with a little white smoke coming through the hub at high RPM. I only goosed it a bit twice to check.
Can anyone point me in the right direction as to what this might mean, and how to do some preliminary diagnosis before considering taking it to a shop?
The seas were smooth with no wind and we were making about 1.7 knots, though there is almost always current along there to confound speed determination. The motor would not respond at all to throttle, other than to sound a bit throatier as the throttle was opened. After a few minutes, I tried the key-push idle control, which worked as normal and I bumped it to the highest idle setting, which gave us 2.2 knots or so and we got back home. Those are typical speeds at idle. My impression was that the throttle would not produce those RPMs, though the idle setting did, but I probably didn't test that conclusion carefully enough.
Once on the trailer back home I put the muffs on and let it idle a bit, then tried the throttle and it appeared to rev fine and quickly, with a little white smoke coming through the hub at high RPM. I only goosed it a bit twice to check.
Can anyone point me in the right direction as to what this might mean, and how to do some preliminary diagnosis before considering taking it to a shop?
