Overheating Revisited

[azxvz1284]

I've read all of the threads, checked the impeller on the pump, hoses, tried different coolant mixes and fluids, have a good thermostat and the over-ride fan switch. Temperature Meter still sits a hair below red and into the green. Yep, I'm in Arizona where riding a bike in 95 degrees in the summer is the low outdoor temp. I ride 35-50 mph in the high gears when possible to generate lower engine heat. I can hear it bubbling in the overflow bottle. What else can I try? Is there another radiator with more capacity and tubes that would fit? A larger fan????

 

Thanks,

 

Richard In Arizona

 

[Flyinfool]

A couple of things.

My temp gage also sits just below the red whether it is 40°F or 100°F outside. So I consider that normal.

I have never noticed or heard bubbling in the system, but to be fair I never listened for it either. That would indicate that you have some air where it don't belong, or even a cooling system leak.

 

Running in a high gear at low speed will actually make the engine run hotter, not cooler. At low engine speed the water pump is also at a low speed and not able to move as much water. It also takes a more open throttle to maintain the speed and the burning mixture in the cylinder is in there for a longer amount of time. This allows more heat transfer to the cylinder walls raising the engine temp. Try running so that the engine stays around 3500 to 4500 rpm. I run low engine rpm in a higher gear to help heat the bike up faster when it is sub freezing temps out.

[frankd]

If you hear the water bubbling in the expansion tank, that means that the water in your cooling system is boiling. Cars, trucks, and water cooled motorcycles prevent this by allowing the pressure in the cooling system to rise to 15psi before the radiator cap vents. At 15psi and with a 50% water/anti-freeze mix in the system, coolant won't boil until it reaches 265 degrees F. This indicates that your system isn't holding pressure. When this happened on my 83, I found that the radiator cap rubber seal had gotten hard and no longer sealed correctly to the radiator. I replaced it and everything is fine now. I bought the cap I used at O'Reily's Auto Parts, but you have to grind one of the ears off of the car cap to allow it to turn on the Venture. I think the replacement was a Stant 1127, but I also think I've read that 2nd Gen caps will also work.

[Razorback]

I also had sudden overheating where I hadn't had it before.

I had recently had my radiator cap off.

 

I removed it, put it back on carefully/correctly and problem went away

 

 

Sent from my iPhone using Tapatalk

[BlueSky]

Just curious. Do you have the stock ignition advance, the TCI I think it is called. if the timing advance is not advancing properly, it will cause the engine to run hotter.

 

I had this issue with a new car engine I had installed a while back. The installer was in such as rush they forgot to properly set the timing and it was too retarded and my brand new engine ran hot.

[dingy]

Just curious. Do you have the stock ignition advance, the TCI I think it is called. if the timing advance is not advancing properly, it will cause the engine to run hotter.

 

I had this issue with a new car engine I had installed a while back. The installer was in such as rush they forgot to properly set the timing and it was too retarded and my brand new engine ran hot.

 

A faulty boost sensor will keep timing from advancing as intended.

 

Gary

[Venturous Randy]

Three things; welcome to the forum and we hope you join as it will be the best $12 you will ever spend on your bike. Second, either put the year of your bike in your header or always note what it is. Third, check the plastic hex nut that is the by-pass valve below the radiator. The top of the letters should point to the 5: 0:clock position. If it is open and the water is not going through thermostat, it can go through too fast to cool.

RandyA

[KIC]

Here is some reading with pictures as to what to know about the stupid way they have the bypass mounted and why up is down and down is up and you will be confused..

[videoarizona]

Thinking out loud here...(uh oh)...

 

If the by-pass valve is upside down when normal and right side up for draining...that makes sense to me. If you can read it, you are draining! Convoluted logic, I guess!

david