When the engine is too hot?

Afan · Aug 1, 2015

Temp gauge shows 1/4 in 80% of time (interstate, highway etc.) On street, after numerous switching gears, revs, quicker starts, it will get to 1/2 of gauge.
But, maybe a month or so ago it started getting very hot when riding in traffic. Very uncomfortable for my legs. I'm not talking about burning my legs but usually I spread the legs away.

The fan kicked on just few times since I bought the bike about year ago.
What could be a problem?

Gymbo · Aug 1, 2015

Check the overflow tube where it leaves the thermostat housing....common place for it to crack.

Bush · Aug 1, 2015

So what is the gauge saying at these times?? If it isn't going up any higher than normal, there's no problem. It is difficult to actually hear the fan come on while riding, so check it out while off the bike without your helmet on.
Also, I'd suggest you need to get some proper riding pants, as jeans are pretty useless as protectors from engine heat, not to mention road abrasion. I say this from what I see in your avatar.

Nashcat · Aug 1, 2015

Last week, Janis and I took a ride in 96 degree heat. I wore mesh riding pants over a pair of shorts and my legs really cooked when stopped in traffic. I'm going back to non-mesh riding pants over long jeans, which is much cooler on the legs. I've had the ST for 4 years, and this was the first time riding with mesh/shorts combination. Won't do that again!

Ride Safe
John and Janis

Slasher · Aug 1, 2015

I would think you don't have a problem at all unless the temperature does not go down when the fan kicks on. My bike never gets over the first quarter of the gauge unless in traffic. At that point, it will get to around 3/4 of the gauge and the fan will kick on. You can usually tell the fan is on, especially while sitting, because all that hot air will be coming right at ya. When the fan comes on, the gauge will usually drop pretty quickly to half and the fan shuts off again.

Afan · Aug 1, 2015

Bush said:
So what is the gauge saying at these times?? If it isn't going up any higher than normal, there's no problem.

If my *** slowly cooking, regardless of what's gauge sayin', then I see it as a problem

Bush said:
It is difficult to actually hear the fan come on while riding, so check it out while off the bike without your helmet on.

That's very true.

Bush said:
Also, I'd suggest you need to get some proper riding pants, as jeans are pretty useless as protectors from engine heat, not to mention road abrasion. I say this from what I see in your avatar.

That was shortly after I bought the bike. I bought TourMaster pants and I'm very happy - except these hot days.

But plan to buy a mesh pants before the end of the season.
A.T.G.A.T.T. 100%

Afan · Aug 1, 2015

Slasher said:
I would think you don't have a problem at all unless the temperature does not go down when the fan kicks on. My bike never gets over the first quarter of the gauge unless in traffic. At that point, it will get to around 3/4 of the gauge and the fan will kick on. You can usually tell the fan is on, especially while sitting, because all that hot air will be coming right at ya. When the fan comes on, the gauge will usually drop pretty quickly to half and the fan shuts off again.

So, there is a chance that I don't hear the fan and the "hot" feeling I have is actually fan blowing hot air into me? Hm... Interesting idea. Didn't think about it...

jerryvolkers · Aug 1, 2015

My 1999 ST1100 idle speed will drop 100-200rpm when the fan cuts in at a stop light, then my legs start to get warm!

Afan · Aug 1, 2015

Looks like there was something related to coolant (?!?!?). I flushed the coolant and had (short) ride through in the traffic and everything was ok.

When the engine is too hot?

Afan

... and this is my real name.

Gymbo

R.I.P. - 2021/08/30

Bush

Nashcat

Slasher

Afan

... and this is my real name.

Afan

... and this is my real name.

jerryvolkers

Afan

... and this is my real name.