when the engine starts warming up after 1 or 2 hours running hard or not it starts temporarily miss firing at around 2500 RPM.
you can hear and see the motor drop and raise RPM slightly
(between 2000 and 2500 rpm for around 1/10 of a second continuously)
when throttle is given passed 2500RPM the RPM drop goes away and the motor sounds fine but is only producing 75kph instead of 105kph.
I thought it may have something to do with over heating after talking to some people so I purchased a new impeller due to a notice in tell tail water pressure drop, installed it and found no difference in pressure,
am eager to see the results ..... have not yet taken her out yet
engine details : 225AETO 6K7 UL 701420
any help would be much appreciated.
FYI
after more diagnosis I found a valve blocked open by rubbish, the one that goes between the cooling veins and the exhaust (it opens to relieve pressure on instruments at very high RPM - high water pressure - )
so being blocked open most of the pressure that was needed to reach the top of the heads at low RPM - low water pressure - was being flushed out the exhaust.
pees like a horse now
you can hear and see the motor drop and raise RPM slightly
(between 2000 and 2500 rpm for around 1/10 of a second continuously)
when throttle is given passed 2500RPM the RPM drop goes away and the motor sounds fine but is only producing 75kph instead of 105kph.
I thought it may have something to do with over heating after talking to some people so I purchased a new impeller due to a notice in tell tail water pressure drop, installed it and found no difference in pressure,
am eager to see the results ..... have not yet taken her out yet
engine details : 225AETO 6K7 UL 701420
any help would be much appreciated.
FYI
after more diagnosis I found a valve blocked open by rubbish, the one that goes between the cooling veins and the exhaust (it opens to relieve pressure on instruments at very high RPM - high water pressure - )
so being blocked open most of the pressure that was needed to reach the top of the heads at low RPM - low water pressure - was being flushed out the exhaust.
pees like a horse now