60hp overheating?

[andy6374]

1987 60hp VRO.<br /><br />Oil injection is disconnect and engine is run on a premix.<br /><br />Just replaced the thermostat and two pressure relief valves, grommets and springs. After about 1-2 mintues of idling on the muffs a steady overheat tone came on. Before this the tell-tale seemed to get progressively warmer. I killed the engine. I lifted the cowl and the cylinder heads didn't seem that warm at all. I could keep my hands on them, but the exhaust plate was hot to the touch.<br /><br />The new springs seemed harder to compress than the older ones and I thought that this would be normal since the old spring looked old and crappy. What do you think is causing the overheat? Tstat, pressure relief valves?

 

[andy6374]

Re: 60hp overheating?

Just went out and turned the key switch to the "ON" position and the buzzer came on. It's probably just the overheat sensor grounding out.<br /><br />Yet, the exhaust plate was a little to hot for comfort.

 

[andy6374]

Re: 60hp overheating?

Alright I've been away for 7 weeks and now I want to get this buzzer situation figured out. Like I said when I start it it will run fine for the first 2-3 minutes on the muffs. The tell-tale stream will get increasingly warmer. For reference the tell-tale is routed from the exhaust plate. Finally the warning buzzer comes on....but it is the beep beep beep. I know this is the low oil alarm, but the oil injection is disconnected and all the wires have been cut and sealed up.

Now....to make the story a little more confusing. Once I turn the engine off obviously the low oil alarm stops. But when I turn the key back to the "on" position it has the steady alarm...ie. overheat???? I don't understand this one.

I can hold my hands on the cylinders heads for a couple seconds so they are not too hot (normal I'd say). But the exhaust plate is very hot. However I know the overheat sensor is located near the #1 cylinder so I don't know how a normal temp cylinder head and hot exhaust plate could make the alarm go off.

Sometimes, if I turn the engine off for a couple of hours and then turn the key back to the "on" position the alarm still goes off. WHat always cures the problem is if I disconnect and reconnect the small harness which routes the wires for the tach,overheat,low oil, from the engihe to the control/throttle box. What the hell is going on here? I know it is a simple system, but I am at a lost. I mean...low oil alarm...then overheat???

confused and somewhat irritated
-andy

 

[ob]

Re: 60hp overheating?

Is the original VRO wire harness disconnected?Are the two wires from the oil reservoir disconnected?If you are mixing 50:1 in this engine and doing away with the vro feature,they should be.When was the waterpump last replaced?

 

[andy6374]

Re: 60hp overheating?

Yes the two main wires from the oil reservoir are disconnected, or at least I cut them and put some heat shrink on the wires.

What about the warning alarm still coming on hours after the engine was shut off? The tan wire isn't chaffed so it isn't grounding out to the block. Maybe its the overheat switch itself .

I am running a 50:1 premix.

As far as the waterpump, I don't know. I got the boat for free because according to the guy "the engine sucks and doesn't run". Once I recieved the boat I realized his problem was burnt out ignition coil ground wires. Whoa...it's alive!

I trying to sell the boat, but before I put in on the market I wanted to rebuild the carbs and go throught the cooling system. So I rebuilt the carbs and replaced the tstat and pressure relief valves. The waterpump was put on hold for the new owner because I applied more than sufficient torque to L/U bolts and they wouldn't budge. I have enough to do between my own boat and engine that I really don't want to deal with broken L/U bolts. But the waterpump could very well be the problem! Sorry for the long story..