Hi, thanks for your answers!
Well, I have discovered that the thermostat that was fit into the bike was not an oem, and it differs in dimensions.
I read the post that rum is talked about, and some has posted a picture with the OEM measurements, and the Toyota one ( at least the one I've here) is really close to the OEM measurements.
The thermostat gasket is too wide, and doesn't fit into the diameter tube.
May be I can sand it a bit, or find a substitute, as posted in:
https://www.motobrick.com/index.php/topic,4903.msg92831.html#msg92831I've boiled the Toyota one, and with a cloth, I've tried it into the position on the bike.
The feeling is that the bypass element, touches the end first, and then I need to push to arrive to the final seated position, when cold, the bypass circle, doesn't touch the end to seal it.
BMW OEM measurements:
85°C, Flange: 48mm, Foot: 27,7mm, Height:30mm (foot to flange)
https://www.euromotoelectrics.com/product-p/thermostat-716.htmHere the rough measurements of the Toyota Corolla 1.6 one: ( Calorstat by Vernet, TH6484.82)
82C, Flange 48mm, Foot: 28mm, Height:33mm
So I'll try to resolve the gasket and try.