Help, help !!!!

[sticka360]

Hi All !!
UK summers starts again !!

Can someone please help me? My Yamaha 50hp DETO Autolube 1989/90
Still having problems Ive had 3 mechanics and still cant sort !""!

First off, when I turn the key there is no alarm (should there be, as some outboards have ?) When I turn the key she starts first time and idles very well for ages and can restart again no probs. When I throttle out no worries, after about 10 mins or so at half to 3/4 throttle the power starts to "fade" then the engine goes to sounds like firing on 1 cylinder, just wont rev up to more than 2000 revs (approx) the engine is pumping water out the back no worries ??!?!? I have all the carbs cleaned, new fuel lines / Tank filter changed !?!? Is this a sign that the engine is over heating ???? When I take it to a mechanic on land.....you guessed it the engine on muffs goes on all day not missing a beat !!!!! Please can anybody help ?? ps I have also changed the CDI unit, Plugs cleaned are wiring, checked compressions etc. Idea........even though there is water pumping out the back through the tell tale, could this still not cool the engine (If thats whats the probs ?)

Your very, very frustarted

Mr Sticka360 !

[99yam40]

Test the alarms system to see if the buzzer works as it should, key on by itself will not test it. You will have to pull the pink wire off the temperature switch and ground it to head with key on to see if it works. Or maybe pull the kill switch with key on may bring in the alarm for testing.

Could be over temp or oil level putting it into safe mode.
You can use a timing light to see if that is what is happening as the timing is not allowed to advance properly if there is an alarm in.

[sticka360]

Tried the kill switch, the engine cuts out as it should do. Have never heard the alarm work before on this engine !! Ref the timing light it seems to only go into a like stanby mode when being used under load, never been able to use timing light when at sea so cant tell how the timming is !! Is the alarm on these engines only for oil (Autolube) and temp ???


Ref the cdi unit the fault is only there when after playing use for 10-20 mins or so, would a cdi unit ....decide hey I wanna stop working going into a stanby / limp home limp home mode ???? or would CDI unit work or not work at all ?

Cheers

sticka