1987 dt85 alarm at high rpms

[river37091]

engine runs fine at half throttle,as soon as u kick it up alarm goes off.new,w-pump,t-stat,head gasket,and heat sensor.engine oil pump disconnected,pre-mix 50 to 1.also tach doesn't work any help is appreciated,roy

 

[bossee]

Re: 1987 dt85 alarm at high rpms

Hi,<br />Have this outboard been running fine with premix 50:1 (fuelil) before this "alarm" problem?<br /><br />Have the oil alarm (oil level and oil flow) been disconnected also?<br /><br />Pros and cons with premix but the outboard actually runs best with the oil injection system in use. On Suzuki 2-strokes You get mix of 150:1 at idle and low RPM and gradually as You increase RPM it is 50:1 at WOT (wide open throttle) for better lubrication. It is in lower RPM range the outboard will get to much oil and you may get fouled spark plugs.

 

[river37091]

Re: 1987 dt85 alarm at high rpms

bo this is roy again.same engine.have 2 post going.maybe he should run 100:1?willcheck oil alarm and let u know

 

[bossee]

Re: 1987 dt85 alarm at high rpms

Hi,<br />No 100:1 will be to little oil at higher RPM. You do not want poor lubrication...

 

[DAG4Bama]

Re: 1987 dt85 alarm at high rpms

I have the same problem and same motor, advise with what you found out please.

 

[jim dozier]

Re: 1987 dt85 alarm at high rpms

I used to have a DT85 that would set off the temp alarm after a few minutes at WOT. I serviced the cooling system from top to bottom, put in new head gaskets (all of which were in need of replacement) only to find that it still overheated sometimes. When I finally got around to installing a tachometer I found the engine to be grossly overpropped and max rpm was only 4400 rpm. When the engine was repropped for 5800 rpm the engine no longer overheated. Check your rpm at WOT.