Internal Zinc anode replacement. 1987 Yamaha 115Hp

ozkor

Cadet
Joined
Dec 7, 2014
Messages
12
I think I need to replace the internal zinc anodes in my 1987 115Hp Yamy. This is because the water cooling system was blocked up and I unblocked it using actetic acid %20 mixture. It worked really well and was using the motor with no issues for 12 months. Now after sitting for about 3 months with just running the motor every month in the shed. I went out last weekend and to my suprise the heat alarm comes on after running it at 5000rpm for about 10 mins. I am flushing it out again and suspect it will be fine but I realise that the issue must be corrosion. I assuming I need to replace some zinc anodes which the acid would have gotten rid of anything that was left of them.
Are they difficult to replace does the heads need to be removed. I am worried about removing heads as being an old engine I am guessing the bolts could well break.
Any body done this sort of thing before.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
I believe removal of the heads may be "opening the can of worms" due to nuts/bolts may be stuck with corrosion and break off when you attempt to remove them....especially on a 28 year old motor. Maybe check your water pump, thermostat and pressure control valve first....
 
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