1994 Yamaha 200 hp Salwater series overheating alarms!

25contender

Recruit
Joined
Jul 22, 2011
Messages
5
I have a pair of 1994 Yam 200hp Saltwater series on a 94' 25 Contender, sea trial went fine no alarms everything was perfect. Bought the boat, week later took her out and punched it out of the channel and for a minute or two ran at about 48mph then my overheating alarms went of on the starboard engine. I went and bought a pair of impeller kits and changed housing,impeller, the hole nine yards.. took her out again, and again, the alarms sounded.just thought id throw this in there, the previous owner had taken thermostats out and had been running it without, so that eliminates the thermostats being bad. but still i bought new ones and still alarms went off. i called a few mechanics and got a few different opinions. SO all in all ive replaced impellers, poppet valves ( werent bad at all ) , and thermostats. nothing seems to be working. the previous owner told me he had a similar problem about a year before he sold it and he replaced the temp switches, so i figured there still good. i brought a mechanic on board and took her out again and he seemed as confused as i was, heads were normal temps, sensors were tested and supposivley fine.. please help!

any advice is accepted and appreciated! thanks :)
 
Last edited:

poni302

Seaman Apprentice
Joined
Jul 26, 2010
Messages
30
Re: 1994 Yamaha 200 hp Salwater series overheating alarms!

Long shot but are you getting oil injected into the gas . Maybe the alarm is for low oil which would cause the engine to over heat also . I'm a newbe but it might be worth a look.
 

25contender

Recruit
Joined
Jul 22, 2011
Messages
5
Re: 1994 Yamaha 200 hp Salwater series overheating alarms!

thanks for the reply,
Yea i was told to look at that also, should of looked last time i ran it but was too overwhelmed with the alarms going off. but diffenetly worth chacking out. thank you Poni, appreciate it!
 

25contender

Recruit
Joined
Jul 22, 2011
Messages
5
Re: 1994 Yamaha 200 hp Salwater series overheating alarms!

other than the oil injection, any one have any other ideas?? everything helps!
 
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