How hot does your Ural get?

[AlanCT]

I recently noticed with some alarm that when I park my '05 Tourist after riding for an hour or so, the motor is hot enough that the valve covers will actually sizzle if I spit on them.

I know that spitting on your Ural is uncool and that the correct method is to piss on it, but anyway . . .

What is going on here? Is this unusual? I've never had an air cooled bike before. I should also mention that the oil is fresh and at the full mark, and that the riding conditions were undemanding.

I had been planning on taking a multiday trip and flogging the rig up Mt. Washington this summer, but now I'm wondering if that's a good idea.

[Blue Ridge Wheeltor]

Mine doesn't get that hot. Much discoloring of the pipes?

[windmill]

Running hard on a warm day, heads will be 300, valve cover 200, oil pan 175, and engine case below alt 190, as measured with IR thermometer. Don't waste time with a dipstick thermometer, they don't give an accurate reading of the oil temp, heat transfer through the case from the head will cause it to show exaggerated reading. Air cooled engines radiate heat directly, instead of dissipating heat through a cooling system, so they seem hotter.

[IsAnOzzie]

Don't waste time with a dipstick thermometer, they don't give an accurate reading of the oil temp, heat transfer through the case from the head will cause it to show exaggerated reading.
Um the oil making direct contact with the dipstick thermometer AND said casing will be the correct oil temperature.

The oil can anly be one temperature right?

heat transfer through the case from the head will also heat the oil to the indicated temperature on the dipstick thermometer.

Or is the heat of the tea in the teapot exaggerated by the proximity of the sugar bowl? The thermodynamic transmission of heat through the engine case is..... my brain hurts.

[windmill]

Originally Posted by IsAnOzzie

Don't waste time with a dipstick thermometer, they don't give an accurate reading of the oil temp, heat transfer through the case from the head will cause it to show exaggerated reading.
Um the oil making direct contact with the dipstick thermometer AND said casing will be the correct oil temperature.

The oil can anly be one temperature right?

heat transfer through the case from the head will also heat the oil to the indicated temperature on the dipstick thermometer.

Or is the heat of the tea in the teapot exaggerated by the proximity of the sugar bowl? The thermodynamic transmission of heat through the engine case is..... my brain hurts.

Ok, I'll try to describe in detail so anybody can understand what I have observed.

I had a dipstick thermometer. When fully warmed up, the dial would indicate between 110c and 120c, that's a little less than 250f. When I change the oil, I always get oil on My hand when I remove the drain plug, its hot, but 250?

I have doubts, so I check the temp of the oil in the coffee can with My IR thermometer, its a little over 180f. So naturally I'm pissed, I spent $75 for a faulty dipstick unit. I figure I will check it against a lab thermometer in boiling water, as long as I know how far off it is, I can still use it. Well its not off, now I'm thinking WTF?

I finish the service, go for a ride, it shows an average of 115c, but the IR shows the oil pan to be 175????? I get an idea, I go home, put the stock dip stick back in and ride around for a while, letting the thermometer dipstick cool off. When I get back, I pull the stock one out and I stick the dipstick probe in the engine being sure it is in the oil, but don't screw it in or let it contact the case, 10 seconds later ta-da it reads a little over 80c, then I screw it in, a few seconds later it is reading about 110c

My conclusion. It is accurate at the probe, BUT if the thermometer body is also heated, It shows the temperature that it is heated to if it is greater, so in fact it doesn't show oil temp, but an average engine temp. That's not a bad thing, as long as You understand what it is showing You.

I ended up trading it for some winter gloves, it was to much of a pain to get in, and out. I gave up worrying about oil temp's a long time ago, 24000km and it aint over heated yet.

[Tarka]

You people amaze me with your ability to find new things to worry about.



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[IsAnOzzie]

Windmill, thanks for your full explanation of the situation, it Certainly clears up any misunderstanding of the temp reading.
I tip me hat to you sir.

[AlanCT]

Okay, but should it really be sizzling hot? The header pipes are blue-to-gold, but haven't been getting darker that I've noticed. It runs great, and has been for the year and a bit that I've had it. I don't know if this is how it's always been or a new condition. Perhaps the heat spikes when I park and the airflow stops. The Soviet Steeds folks mostly said not to worry about it, but I am anyway.

By the way, Blueridge Wheeltor, this is none other than the Fleabay rig that you steered me towards last spring,and it has been great. I won't hold you responsible for my misery if it melts into slag by the roadside!

[windmill]

Originally Posted by AlanCT

Okay, but should it really be sizzling hot? The header pipes are blue-to-gold, but haven't been getting darker that I've noticed. It runs great, and has been for the year and a bit that I've had it. I don't know if this is how it's always been or a new condition. Perhaps the heat spikes when I park and the airflow stops. The Soviet Steeds folks mostly said not to worry about it, but I am anyway.

By the way, Blueridge Wheeltor, this is none other than the Fleabay rig that you steered me towards last spring,and it has been great. I won't hold you responsible for my misery if it melts into slag by the roadside!

As long as You don't smell burning oil, Your ok. If the heads don't make water sizzle, the engine is running to cold.

[Nemo DeNovo]

What color are your sparkplugs? Post a picture of them if possible, and note which is right and left. If your pipes are blue it's running lean. Air-cooled bikes with carbs have to be tuned dangerously lean to pass US emissions, and this should be corrected ASAP.

[Tarka]

Originally Posted by Nemo DeNovo

If your pipes are blue it's running lean. Air-cooled bikes with carbs have to be tuned dangerously lean to pass US emissions, and this should be corrected ASAP.

Pretty much any chromed pipes will blue,regardless of jetting...but on the subject of lean jetted Urals,the early 750`s used to come into the UK with 118 main jets which did lean them out quite a bit.

It`s been found to far better to fit 125 main jets if on stock pipes (indeed,that`s what they come into the UK with now) and 130 or even 135`s on free flowing pipes.

Defo worth checking your jet sizes if you`re unsure.

[Blue Ridge Wheeltor]

Alan,
Also post a pic of the pipes along with the plugs.
Any pinging on acceleration?
What weight oil and grade gas are you using?
Have you done any mods like cat removal or K&N?
Think you could be lugging the engine?
If I am thinking correctly, you've had the bike over a year. How do the compliance fittings look? Could you have an air leak causing a lean condition?
I don't want you joining the Holy Piston Club.

[Nemo DeNovo]

Jetting is also altitude sensitive. If you are close to sea level you need bigger jets. Smaller ones for the mountains. But at part-throttle your idle jet and needle jet control the mixture, so main jet size is only of major importance at 3/4 throttle or more. Does it run hot like that when riding around town or out on the highway? There is a certain amount of adjustment on your idle and needle jets. Lets see the color of your plugs first, and pics of your carbs too if possible.

[AlanCT]

I put in #45 pilot jets several months ago, and my plugs are now both the same shade of cardboard tan (they were gray with the stock pilot jets).

The outboard header pipe is bluer than the inboard one, which I'm told is normal due to the better airflow onto the inboard cylinder. The color on neither pipe has changed in any noticeable way.

The rig runs with no pinging, stumbling, or rough running at all. In fact, it runs great! I noticed the sizzling hot valve covers by accident when I carelessly touched one. Maybe it's always been this way? BillyG, the Ural maintenance guru, claims tha that this level of heat is fine and to ignore it if the rig runs fine. It still bothers me though.

I'm on a tank of 93 octane at the moment, although I do use lower octane too sometimes. The oil is 20W/50, is up to the dipstick's full mark, and has about 1000 kms on it.

There are no mods to the air filter or pipes, unless the PO did something to them. This is highly unlikely, since he struck me as a real hands-off guy.

I'm pretty careful to keep the motor wound up and not to lug it.

I did check the valves today and the inboard exhaust valve was tight, although I doubt any connection to the heat.

[Nemo DeNovo]

Originally Posted by AlanCT

I did check the valves today and the inboard exhaust valve was tight, although I doubt any connection to the heat.

That could do it right there. If you have a tight exhaust valve, it may not close completely with the engine at operating temp. This would allow combustion gasses to escape, causing undue heat transfer to the head. Kinda like taking a blowtorch to your exhaust port. Check your timing too.