Cooling System Operation for K Bikes

[frankenduck]

See attached.

[RSMITH]

have any of you ever taken out the thermostat on the K 100?

Are there any serious consequences for doing just that?

[Photog]

Dunno about the K engines, but on most engines, the cooling system is designed with the restriction presented by the thermostat in mind. Without it, some parts of the engine may not get adequate cooling.

Low coolant temps might throw off the fuel injection also.

[frankenduck]

have any of you ever taken out the thermostat on the K 100?

Why?  :dunno

[wmax351]

have any of you ever taken out the thermostat on the K 100?

Why?  :dunno

I ran mine without it for 10 miles, with radiator flush in it. Worked fine. Heated up too. The cooling is less efficient at higher flow.

Makes it much easier to do a flush. Then put the thermostat back in, and add the gatorade.

[RSMITH]

I work at a large international gearbox manufacture and repair company and we have a siginificant amount of gearbox failures as result of overheating on BMW cars. The vehicles actually require larger gearbox coolers and engine cooling systems for our operating conditions and as a result we have found that by removing the engines thermostat, we have been able to reduce the failre rate for the customer as well us claims for the primary customer as a result of overheating failures of the gearboxes.

I was just thinking that it may be better to do the same,  Was thinking as being an older system and not as efficient anymore whilst sitting in traffic it may be better to just take it out-but the bike is over 25 years old and it has operated here in the same conditions without trouble so it must be fine.

[frankenduck]

And why would you want to run an engine at a lower engine operating temp than it's designed for?

[Scott_]

And why would you want to run an engine at a lower engine operating temp than it's designed for?

Agreed, you are asking for emissions issues, possible fouling issues as well. If the engine cant reach it's intended temp the FI controller is going to feed it rich.

[thebob]

Seeing as the thermostat opens at 85C that should be a reasonable coolant temperature to aim for.

The fan comes on at 103C so if you had a thermostatically controlled variable speed fan that comes on at 85C and reaches full speed at 103C you would get a good feedback loop.

I think the main problem is when the bike is stationary, the fan cycles on and off. So a signal from the VSS to disable the variable fan system at 10mph would be enough I think.

[frankenduck]

Or if the heat is too much for you then you could just buy a different bike that isn't as hot.

[thebob]

Or if the heat is too much for you then you could just buy a different bike that isn't as hot.

And where would the fun be in that? I wouldn't have anything to play with!