Overheating on rides that were fine in other years

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shiftless
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Overheating on rides that were fine in other years

Post by shiftless » Tue Aug 28, 2018 6:16 pm

30K+ K on my 2011 that has had 12v bilge blowers mounted behind the knee guards to blow directly onto the jugs. My ride to work includes 15 miles of highway at 60mph or so, and sometimes a wait of 2 or 3 lights just to get off my exit on the way home. I realize that highway warms it up, and sitting still at a light is not a Ural's favorite thing, even with fans pointed at the jugs. Overheating has even happened on the way to work, so at night, when it is cooler, and no traffic to sit in after leaving the highway. This overheating was not an issue in earlier years on the same shift and same roads, saw it some last year, seems to be getting worse over time.

Smell the heat at lights, feel the loss in power, feel the occasional mild sputter become harsh backfire, simply pull over in the shade, wait 10 minutes or more, and it runs fine again. Summer day temps here perhaps higher 80's to 90's.

Plugs get cleaned every couple of tanks, frequently find one or the other blackened, not always the same side. Fuel does sometimes get additives for cleaning and water (amsoil, star tron) and I use high octain to reduce the 10% ethanol content some idiots required in my state. Air filter recently cleaned. Power Arc ignition since purchased, with iridium plugs used after first change from stock, and plug wires also changed years ago - meet Power Arc specs. After break in running synthetic oil.

Exhaust had the cats disintegrate years ago, and I drilled up the center of the pipe to increase flow a little, just 1/4".

Speculation: lean is hot, so might check fuel filters in tank, perhaps not flowing enough for highway speeds. Valve lash? Jugs/bike degreased and rinsed at end of the winter salt season so it's not just too dirty to radiate heat. Something changed how it heats up, so something needs to be found to make it right again. My searching has not revealed any clear path to success.
Still like Charlie Chaplin's 1940 talkie "The Great Dictator"; had to abandon it as the inspiration for the theme of my Ural's paint scheme. People can't seem to tell satire from support. Too much public education.

http://en.wikipedia.org/wiki/The_Great_Dictator

2011 Gear Up from V.T. CYCLES, Pwr Arc Ignition, sprayed USMC 383 Green w/blacked engine/exhaust

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Re: Overheating on rides that were fine in other years

Post by jeffsaline » Tue Aug 28, 2018 7:30 pm

Have you checked the ignition timing?

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Re: Overheating on rides that were fine in other years

Post by Niteblues » Tue Aug 28, 2018 8:28 pm

shiftless wrote:
Tue Aug 28, 2018 6:16 pm
Speculation: lean is hot, so might check fuel filters in tank, perhaps not flowing enough for highway speeds.
since it got worse over time, this seems like a reasonable speculation.
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Re: Overheating on rides that were fine in other years

Post by windmill » Tue Aug 28, 2018 11:42 pm

Check compliance fittings very carefully for cracks or separation. Also check any hoses or caps on the carb vacuum ports.

There's definitely something wrong, a stock, or correctly modified Ural shouldn't have any heat issues under the described conditions.
Barry

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Re: Overheating on rides that were fine in other years

Post by Lokiboy » Wed Aug 29, 2018 6:31 am

Also, enrich the air/fuel screw a 1/4 turn. Do you normally adjust it as the temps change? Like you surmised, most things, over time things loosen up.
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Re: Overheating on rides that were fine in other years

Post by RC20 » Wed Aug 29, 2018 6:35 pm

And you could have exhaust pipes plugging up (and over time) if the cats collapsed and 1/4 inch is not going to affect anything.
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Re: Overheating on rides that were fine in other years

Post by LRP » Wed Aug 29, 2018 8:53 pm

Hope you are using 91+ octane as specified.
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Re: Overheating on rides that were fine in other years

Post by shiftless » Thu Aug 30, 2018 7:32 pm

LRP wrote:
Wed Aug 29, 2018 8:53 pm
Hope you are using 91+ octane as specified.
High octain, generally 93, sometimes 91 if that is the highest choice.

Today tried draining tank, checking filter. It looked good, which is bad, because seeing a lot of trash would mean an easy fix. The riser pipe for normal had trash on it, and some filings were between the reserve filter and the riser pipe, but the actual filters were amazingly clear of debris.

Replaced a few inches of the vacuum hose to the petcock, and the clamps at either end. Hose looked squeezed, the clamps were cheap, and frankly it was just easy enough to do with materials on hand.

Torqued the heads to 40 ft/lbs, set valves to .004". Chair side either tight, or just frozen, other side exhaust was >.007, just didn't bother to see how much more (and they were all checked prior to torquing the heads).

Next step ride it and see. The nature of the trouble will not show up in a short test run, so will take a while to know what works.

:boogie:
First ride to/from work was cooler outside, not as good a test as I would like, but seems better. Need to adjust/balance the carbs after the valve settings changed, but looks positive so far. Speculation, bad/blocked/or leaky vacuum hose to petcock limited fuel flow, good test would have been to ride same roads/distance with petcock on RES and see if rode cooler. We still have time for some hot & humid test rides this year.
Still like Charlie Chaplin's 1940 talkie "The Great Dictator"; had to abandon it as the inspiration for the theme of my Ural's paint scheme. People can't seem to tell satire from support. Too much public education.

http://en.wikipedia.org/wiki/The_Great_Dictator

2011 Gear Up from V.T. CYCLES, Pwr Arc Ignition, sprayed USMC 383 Green w/blacked engine/exhaust

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Re: Overheating on rides that were fine in other years

Post by shiftless » Tue Sep 04, 2018 4:01 pm

Still overheating. 80F on way to work, only a couple miles away felt the change, turned on fans and made it.
Put petcock on Prime for ride home to see if vacuum not opening it enough, but wasn't a good test day. Slow to almost stop on he Hwy, couple cars had crumpled the chrome, one in between the east/west lanes had failed to keep the shiny side up. Barely past this slowed again, someone had a tow truck changing the tire on a car. Again moving slow, saw black SUV and police on grass in gully between the lanes, turned out the SUV was "unmarked" running police lights after smashing up the front good. I could go months with no slowdowns, then 3 today within a couple miles. So too many longer slow periods for a valid test. Did overheat off Hwy, just let it sit in the shade for a bit, was fine for the rest of the way home. Will try Prime again another day.
Still like Charlie Chaplin's 1940 talkie "The Great Dictator"; had to abandon it as the inspiration for the theme of my Ural's paint scheme. People can't seem to tell satire from support. Too much public education.

http://en.wikipedia.org/wiki/The_Great_Dictator

2011 Gear Up from V.T. CYCLES, Pwr Arc Ignition, sprayed USMC 383 Green w/blacked engine/exhaust

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Re: Overheating on rides that were fine in other years

Post by mexican » Tue Sep 04, 2018 5:01 pm

What is the cylinder temperature running at when you feel bike lost performance?
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Re: Overheating on rides that were fine in other years

Post by n3303j » Tue Sep 04, 2018 10:27 pm

Check your timing with a timing light. Some users have had the PA encoder disk on the end of the cam slip out of location.

I would never be brave enough to crank the head nuts to 40 ft/lb. I don't like installing Helicoils. Factory torque specs 36 ft/lb. Used to be a lot of posts about repairing pulled studs.

I do like the old BMW boxers numbers and stay at 25 ft/lb. No problems on Ural in the first 80K KM.
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Re: Overheating on rides that were fine in other years

Post by rivers » Wed Sep 05, 2018 11:37 am

What criteria are you using to determine it's overheating? Doubt it's the petcock screen not allowing enough fuel to feed the carbs. If that were the case they'd run dry and the motor would quit.
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Re: Overheating on rides that were fine in other years

Post by mexican » Wed Sep 05, 2018 8:54 pm

Similar reason why I was asking about, What is the cylinder temperature running at when you feel bike lost performance?
Need some real data before you start adjusting many things
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Running 45 pilot & 130 main)
NGK BP6HS spark plug

2007 Vmax

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Re: Overheating on rides that were fine in other years

Post by LRP » Thu Sep 06, 2018 2:10 pm

Get rid of the vacuum operated petcock. There are several choices for good manual petcocks, but Yamaha style seems the best.
Tee in a vacuum gauge to the petcock vacuum line and you will see why.
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Re: Overheating on rides that were fine in other years

Post by Mr Wazzock » Fri Sep 07, 2018 12:49 pm

mexican wrote:
Wed Sep 05, 2018 8:54 pm
Similar reason why I was asking about, What is the cylinder temperature running at when you feel bike lost performance?
Need some real data before you start adjusting many things
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