How do you know if you are overheating?

[jjwithers]

I've heard stories of airheads overheating but how do you know if you are actually running hot?

What are the symptoms that would make you want to pull over and take care?

Occasionally I experience a high idle when doing a lot of stop and go city riding and often wondered if that was a result of the engine running too hot.

-J

[Ray from Indiana]

Mix up of cause and effect?

Your bike may be running hot because the idle ject is set too lean causing the high idle

check it out

[Duane Ausherman]

In many dozens of cases of piston siezures, not a single rider knew that there was a problem until it was way too late, usually the next day when the bike was started up again.

If the bike doesn't seize up, then it is possible to feel the heat and sometimes smell the burning oil that may have seeped out over time.

When I would be touring it was common for me to remove gloves and put both hands down on the valve covers to check on the heat level. After doing this many times I would get a feel for what was normal under those ambient conditions.

One my first R69S it had a problem with the timing creeping from normal. I never solved why it did that. However, I would have to stop, remove the front cover and correct the static timing before I could proceed. Things were really hot up there, but I had been alerted by being able to hear that the timing was off, not the resulting heat.

I don't think that I answered your question with anything useful.

[jjwithers]

Thanks. Duane, i am now going to get in the habit of touching the valve covers (carefully) to gauge...

[Major Softie]

When you're still really hot, but you stop sweating, that's a definite warning sign.

Now, for motorcycles...

Often there's a difference in sound: engine gets a little "rattly." Oil gets thinner when too hot, after all. Also, knocking is much more likely when too hot. On two-strokes, I've found that the first sign was a loss of power, and then you knew it was already too late.

[mattcfish]

An oil temp gauge is a good thing to have.....the down side is, now you really know how hot it's running when you're stuck behind 10 miles of creaping cars.

[jtoml]

I'm with Duane on the touch test, ditto for the rear drive.

I read somewhere that when the German army issued the spec. which eventually became the R75 side car rig, they required is to run all day at "marching speed" without overheating. Yes, low compression, but also primitive lubricants.

[jjwithers]

An oil temp gauge is a good thing to have.....the down side is, now you really know how hot it's running when you're stuck behind 10 miles of creaping cars.

Thankfully lane splitting is legal in California...

I had a 5 or 10hp leaf blower engine seize on me when i was a kid. I'll never forget that sound. The RPM's got faster and faster... and the pitch got higher and higher... and then a loud yet brief squeal and that was it. Frozen solid and hot as hell.

[Major Softie]

Thankfully lane splitting is legal in California...

I had a 5 or 10hp leaf blower engine seize on me when i was a kid. I'll never forget that sound. The RPM's got faster and faster... and the pitch got higher and higher... and then a loud yet brief squeal and that was it. Frozen solid and hot as hell.

With a two stroke, the rpm's going up is not a symptom of seizure, but of the mixture going lean. Then that lean mixture ends up being the cause of both the rpm increase, and the seizure.

Still trying to imagine a 10hp leaf blower...

[moonbeamerll]

I had a 5 or 10hp leaf blower engine seize on me when i was a kid. I'll never forget that sound.

Isn't that pretty much what every hot rodder, regardless of two wheels or four says? : Man, that mother was really singing. . .just before it went ker-blowy!