My Sprint GT runs hot. I wanted to change the thermostat to rule out its malfunction. However, I saw the price online for a Triumph thermostat as £39!!! Plus postage! That's daylight robbery. I think there are many car thermostats out there which will probably fit and open at the same temp and be more like £5. Before I spend an afternoon down the car spares shop, does anyone know of an alternative?
I don't know that I would be willing to spend ANY money until I am sure what I am buying will solve the problem. I would use one of those electronic non- contact thermometers and sense the upper radiator hose temp. I would be looking for a temp reading of 195°-210°f. You can also tape a mechanical thermometer to the hose an get a reading that is close enough. I would just stick it on with some duct tape and run the engine to get a reading. Also be certain your cooling fan is cycling on and off properly as needed before you start buying parts. ...J.D.
The temp gauge shows bars almost up to top on a hot day. I had an issue last year where the temp light came on after a long and hard run along the autoroute to Calais. I had to turn it off at the passport control and it took an age to cool down and re-start. The day was very hot. The fan comes on fine and the hoses feel hot, so I assume thermostat is opening. Got ECUTune and was going to lower the fan operating temp. Just surprises me - never had any issue like this on a water-cooled bike
I would be inclined to check that the radiator is passing air through before worrying about thermostats. I am of course assuming you haven't yet looked at the radiator, apologies if you have.
Take out the thermostat , test it ! Test method :- put thermostat in a pot , cover it with water , put it on a stove , slowly bring it to the boil , watch to see if it opens ! With a thermometer you can assess whether it is opening at the right temperature. If it is , the problem Lie's elsewhere ! If it doesn't open you have two options ! Cut centre of thermostat out and refit the outer ring or buy a replacement. Refitting the outer ring on it's own is at best a temporary repair , engines treated to this repair take longer to warm up to operating temperature.
This fix won't affect EFI any differently than a carbureted engine , it will just take three times longer to reach running temperature if the bike is ridden and moving air through the radiator before it's hot ! As the opening for coolant to flow through is fully open , it might run slightly cooler in general too. I've used this fix on truck , car and bike motors , it give you time to find and install a new working part...
I had the same problem and I have cleaned the radiator...from outside with warm water, soap an a soft brush and from inside with liqui moly radiator cleaner.....after this procedure I filled up with ready mixed coolant from motul...the bike runs much cooler and I'm very satisfied. I hope it works with the pic.....it shows my 4 years old coolant sorry---cannot upload a pic
