Honda Engine Overheating - advise please

[mhb100]

Guys,

My Honda 90 nearly overheated the other weekend - it put me into limp home mode and if i went over 5kts it would buzz. I did not realise it would do this, but grateful as there seems no obvious damage as it prevented me from overheating.

I've followed the honda diagnostics which seems to indicate either the thermostat or thermo switch was faulty (as it stopped buzzing when i removed the red wire) so i have put in a new thermometer and also cleaned out the flushing pipe realease value next to the thermometer which was also a little salty.

Testing on the muffs It looks like it has worked ok, as the buzzing has stopped.But i notice that when the engine goes upto temperature there does seem to be a trickle of hot water out of the over flow pipe next to the thermostat.

I had not noticed this before and I'm wondering if this is normal. Does any one one know if this is normal?

There was some salt deposits in the waterways and i'm wondering if it needs descaling. Is there a good way to do this?

any advise much appreciated

Mark

[Mollers]

Hookay, I've had most of this with our 50. Firstly, I'd change the stat as a matter of course, for the little that they cost, it's worth it for piece of mind. Secondly, the telltale on our's blocks for a pastime, if you pull the rubber pipe off from the brass fitting on the block and get a strong jet, you'll know that the blockage is either in the pipe or the plastic outlet fitting. Clear it with a bit of soft wire.
If you have a new stat and a strong telltale, it'll be your temp. sensor at fault.

[mhb100]

Thanks Moller

It looks like its sorted now that i've put in a new thermostat and cleaned out all the flush pipes/valves.

Out of interest how to you flush your Honda?.Do you run on muffs, and then also flush through the overflow port back through the head?

I must confess to always flushing through the muffs but not flushing through the flush port on all occasions, so that's probably not helped,and explains why there was some deposits in the flushing port.

I've tried to buy a honda flush pipe but cant seem to get one locally.

Cheers
Mark

[ashbypower]

Originally Posted by mhb100

Thanks Moller


Out of interest how to you flush your Honda?.Do you run on muffs, and then also flush through the overflow port back through the head?

What are you calling the Overflow port?? do you mean the "Tell tale" ??

[mhb100]

On the honda there's a hose from near the thermostat that seems to be some form of overflow pipe/release pressure pipe, which then continues to a port (about the width of a standard hose pipe) which i supposed is better named as as an overflow port. Its not the tell tale.

I dont have the honda manual but i'm guesing that if i flush through the muffs the water circulates around the head and past the thermostat (once upto temperature) but i'm not sure on what circumstanced it also flushes the overflow/pressure release pipe. So i'm guessing that i also need to flush from this port back through the engine and back through the tell tale to keep the water system clear.

Hope that explains it clearer, unfortunately i dont have any honda guide. Im guessing honda have designed this to be the flushing port, replacing the need for the muff's.

[Mollers]

You only need to flush on muffs, but you need enough hosepipe flow to get the telltale running well. Flush for long enough for the stat to open.