Technical New thermostat different

[rawill]

I got a new thermostat for my 1984 70s. I see it does not have the take off point for the small diameter hose that goes to the carburettor. So for now I have blocked that hose. How important is that hose, I assume for heating the base of the carburettor to stop icing etc. So I am assuming it is fine if it does not ice up. And I assume the carburettor will run colder which might help improve economy.

/R

 

[alexGS]

Yep, some later UNO 70SL models (probably SX in the UK) had a small aluminium 'bar' carrying thermovalves and thermoswitch for fast idle/accel pump cutoff systems - this was fed by a small pipe from the thermostat as you mentioned, returning to the inlet manifold water jacket. On those models you'd have to work out some way of drilling a hole for an appropriate fitting but on yours (carburettor heating only) there shouldn't be a problem (if, in winter, you get a problem with the engine faltering after a few kilometres in cold, damp conditions (carburettor icing), well, you'll know the cause...

-Alex

 

[rawill]

Funny thing is I have 2 84 70s models, and an 88 60s. They all need thermostats with the extra take off for heating the carb. However one of them has had an extra take off point welded in to the pipe that goes down the back of motor, by the exhaust.

So I have two thermostats with the extra take off point and one with out. So all is well. Now for a new clutch or three for my little fleet of Unos!!