Mariner 15hp 2 stroke - removing stat/tell-tale

[Max...]

I believe these engines have a 'stat fitted that means the tell-tale pumps intermittently according to the state of the stat (sorry...).

As this is a bit confusing I believe some users remove the stat - any issues with this? do you just take the stat out and fit the cover back on or is a restrictor of similar needed?

My Tohatsu like most engines pumps non-stop and has no stat so presumably it is not a problem running 'cold' all the time?

[Boats&Outboards]

The merc uses a different system to the Tohatsu in that it only "shows" a tell-tale as when the thermostat opens, its constantly cooling itself, with most of the flow going back down its exhaust. The visual tell-tale will start pumping hot, then reduce as it cools. Perfectly normal but can be worrying to some when they look over and see nothing coming out

Generally it'll show mostly at wot. I'd not suggest removing the Stat, as this regulates the running temp so if removed it'll run too cold, with the usual pitfalls of that coming into effect. If you did remove some people fit a restrictor in its place to slow down the flow, keeping it at the right temp but giving a constant flow. My advise is run with it as per manufacturer with the stat in place. You get used to it

Your Tohatsu does have a stat but is designed to always "show" a flow, as a visual aid. Remember that most of its cooling is still dispersed through its prop/exhaust.

Peter @ Boatsandoutboards4sale ~ www.BoatsandOutboards4Sale.co.uk ~ 07930 421007

[Max...]

Thanks Peter, that's very useful. I did not realise the Twat had a stat too and often wondered how these engines got 'working temperature hot' as they obviously pump cold sea water all the time, makes sense of course. Do the stats ever give trouble?

[Fenlander]

>>>I'd not suggest removing the Stat, as this regulates the running temp so if removed it'll run too cold, with the usual pitfalls of that coming into effect.


100% agree. After running our 2001 Mariner 15 with a post stat telltale for some time I'd not take the stat out. As I mentioned in the other thread I put a new stat in mine at the ten year point but the old one was still working fine so saved in the workshop spares box.

Mine only really shows the (correct) intermittant flow at idle or perhaps trolling, once on the plane it is constant.

I think the whole issue is the single outboard boaters fear of breakdown at sea and watching a strong telltale even at idle feels reassuring.

[Locozodiac]

Max,

If your Tohatsu happens to have a bigger peeing port at rear upper middle leg, put your hand there, will feel water as it cools/warms while exiting indicating thermo is working properly.

Happy Boating