Engine may be running too hot

[sen098]

Alright, so the last time I rode the coolant began to boil due to the engine being too hot.

Before then I was sitting in stop and go (not more than 5-10 mph) traffic in 42 degree weather for about 45-50 minutes total. I put in some new coolant and ran the bike around for 10 min to see if it would overheat again. It didn't.

The radiator pump and thermostat seem to be working, since the coolant was boiling (how else would it boil if it wasn't circulating properly).

I'm going to check the plugs to see if they are running too hot later this week. The oil level is at the right level. The (new) coolant is up to the recommended amount now as well.

Got any clues to why the engine got so hot? Or am I just getting worried for nothing and it was simply because I was in traffic for too long?

96 Speed Triple if you are all wondering.

[Roden]

When you were sitting in that traffic, did your cooling fan come on?

Mine comes on when the gauge hits about half way and holds the temperature fine.

You would feel the extra blast of hot air if the fan turned on ok.

Cheers,

Roden

[Readmarx]

the thermostat may not be working correctly. if it were not the rad fan would not come on. there is probably a test in a workshop manual (probably involving water at a set temp).

even if the pump weren't working the water would get hot because it is sat within the barrels of the motor absorbing heat. if the pump weren't working the water wouldn't be driven through the rad to cool it.

it may have been that the old coolant had too much water or been topped up with too much water?

it could also be that the coolant level had dropped too much and allowed air into the system which will allow the motor to get way too hot.

if you've emptied the system and refilled with fresh coolant. run the motor (waited for it to cool) and topped up at the filler and it seems ok I'd put the bike on the stand and run it at a standstill until the rad fan comes on. stay near it incase the temp warning light comes on. if the light is on, but no fan you'll haver to check your fan and the wiring from it.

[ervdrvr1]

Also, have the radiator cap tested. If weak, it will lower the boiling temp of the coolant.

Erv
Deep in the Heart of Texas!

[trubritbiker]

It is not impossible to have an air lock in the system (pump?) try taking the cap off(with a cold engine) and squeeze the hose's gently to try and dislodge any air in the system. I say this because it has happened to me and any bike I now fill with coolant I do use the same process. A cheap option to try.

[trypcil]

Any leaks around the bottom of the coolant pump, a trickle perhaps? If so, get new pump.

[sailfish]

It sounds to me like the cooling fan didn't come on, it got hot and puked its coolant.

[sen098]

Well I have no leaks in the coolant pump or hoses after I checked. I'll open up the radiator to see if there is an air block.

Rode the bike around for about an hour and nothing abnormal happened, checked the coolant temp afterwards and it wasn't boiling.

I'll have to check the fan just in case there may be something wrong with it. Thanks for the tips.

[trypcil]

It's possible that you may be lean off idle, which with a lot of town work and a cooler denser air is making her run hotter than normal - have your fuel screws ever been set?