Best Tune for Hot Running?

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BinDerSmokDat
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Best Tune for Hot Running?

Post by BinDerSmokDat » Fri Jan 31, 2020 11:00 am

So let me start by saying that when I say "tune" I'm talking about ignition timing, carb jetting and valve settings.
NOT EFI maps.
My issue is that my bike is 80% off-road at this point with short pavement trips but mostly rides in the Pines.
That means deep sand and muck, so slow ground speeds at higher revs as wheels slip.

When we ride in long stretches of deep sand my bike bogs down and just can't make power, especially with a monkey onboard.
So if I want to bias my tune to running hot what should I do?

Assuming I'm running at recommended Ural ignition timing and valve settings with jetting changed to slightly richer due to adding Windmill airbox, what do I want to try?
Retard timing? Run a little richer still? Could I be running too rich for these low speeds?

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Re: Best Tune for Hot Running?

Post by Lokiboy » Fri Jan 31, 2020 11:23 am

Running as stated, the engine is running much hotter due to the added load & higher revs. So, my thinking would be a hotter engine, the air is also heated above normal operating temps. Hotter air means the molecules are further apart. What that means is less fuel is needed to maintain the optimal fuel/air ratio.

Therefore, running slightly leaner might be the way to go. At the JDH, rejetting is not practical. However, the air/fuel screw plays a part throughout the entire combustion sequence regardless of throttle setting. Adjusting the air/fuel screw to a leaner setting by a 1/4 or 1/2 turn might help

I’m not a mechanic so I may be totally off base, but I don’t think so.
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Re: Best Tune for Hot Running?

Post by chaos2 » Fri Jan 31, 2020 11:56 am

just for a counterpoint, leaner tends to run hotter and richer has a cooling effect for the intake valves. I'd think keeping every to spec on the rich side, valves on the loose side, timing on the retarded side would be your best bet. Detonation is what you need to avoid. Have you tried a plug check when it bogs down, what jets are you running now?
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Re: Best Tune for Hot Running?

Post by windmill » Fri Jan 31, 2020 12:41 pm

Bogging down under high load at low speeds is usually a sign of being too rich. I would try dropping the needle a hair, and retarding the ignition ever so little.
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Re: Best Tune for Hot Running?

Post by Eric N » Fri Jan 31, 2020 1:47 pm

Swap out your cam for a modified 650 cam from Terry Crawford, it will slightly change your torque curve.

As Barry mentioned, sounds rich, if you have Raceway needles put the shim one higher to drop the needle and see what happens.
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Re: Best Tune for Hot Running?

Post by URALNUT60 » Fri Jan 31, 2020 4:50 pm

1st I have heard of modified cam for 650 from Crawford's Cycle, so how does it change torque curve? Is this a cam designed by Terry or someone else? Is there a thread on here about the product? Cost of cam? Thank you

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Re: Best Tune for Hot Running?

Post by windmill » Fri Jan 31, 2020 4:55 pm

I'm ashamed to say I have one I've yet to install in my Patrol, but I don't remember any of the details.
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Re: Best Tune for Hot Running?

Post by Eric N » Fri Jan 31, 2020 6:22 pm

I'm also putting one in the 2013 as part of my major overhall.

Cam is a 650 cam that's had the end machined to accept the needle bearings of the 2010 and up bikes. 2009 and older may be able to accept an unmodified 650 cam, dunno.

My understanding is 650 cam has lower lift and duration. Google will be your friend in explaining how different camshaft designs can shift the power curve for either lower end torque or higher end horsepower. 2014 and up Urals use a camshaft design very similar to the 650. Part of the reason I'm swapping the 2013 solo to the 650 cam is just to simplify my programming of the EFI, if I have two engines that are pretty close to eachother I can probably get away with the same map. Having the different cam would require a different map for each bike.

Cost was the cost of a 650 cam + machine work. Terry is very reasonably priced, it was not expensive but I don't recall the price.
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Re: Best Tune for Hot Running?

Post by jaybird » Fri Jan 31, 2020 11:52 pm

I’d say it depends on what kind of music your girl likes. :lol: :lol:


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Re: Best Tune for Hot Running?

Post by GHGoodwin » Sat Feb 01, 2020 9:05 am

Try some high octane gas.
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Re: Best Tune for Hot Running?

Post by Who's Ur Grandaddy ? » Sat Feb 01, 2020 12:11 pm

Eric N wrote:
Fri Jan 31, 2020 6:22 pm
I'm also putting one in the 2013 as part of my major overhall.

Cam is a 650 cam that's had the end machined to accept the needle bearings of the 2010 and up bikes. 2009 and older may be able to accept an unmodified 650 cam, dunno.

My understanding is 650 cam has lower lift and duration. Google will be your friend in explaining how different camshaft designs can shift the power curve for either lower end torque or higher end horsepower. 2014 and up Urals use a camshaft design very similar to the 650. Part of the reason I'm swapping the 2013 solo to the 650 cam is just to simplify my programming of the EFI, if I have two engines that are pretty close to eachother I can probably get away with the same map. Having the different cam would require a different map for each bike.

Cost was the cost of a 650 cam + machine work. Terry is very reasonably priced, it was not expensive but I don't recall the price.
I also have a 2013 gear up . When I bought it May 2013 from Raceway , the owner of Raceway ,the late Jim Petty , said that my rig came with the 650 cam that would come with the 2014 models .It also came with the 2014 final drive ( the one with the lower ,separate, more outboard breather )

You might want to investigate with Terry or perhaps Jason at Imwa to see if you already have a 650 cam. It could save you wrenching time and the cost of a redundant cam.

I am also interested in the results of your 2013 efi conversion.
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Re: Best Tune for Hot Running?

Post by VWK75S » Thu Feb 06, 2020 7:39 am

I've got an old Ural oil cooler (came off an ST) I'd sell cheap.
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Re: Best Tune for Hot Running?

Post by rivers » Thu Feb 06, 2020 1:51 pm

BinDerSmokDat wrote:
Fri Jan 31, 2020 11:00 am

When we ride in long stretches of deep sand my bike bogs down and just can't make power, especially with a monkey onboard.
So if I want to bias my tune to running hot what should I do?
I've got no tuning cure for you, just random thoughts... I wouldn't think the Windmill airbox has you running too lean unless possibly paired with an ultra low restriction exhaust like Modtops or Dunstals. Curious..after motor bogs down in the sand and before the hwy run home have you pulled the plugs to see if they're fouled? Back many decades ago in my hot rod and racecar days a lot of the street racers folks with non-stock "built" motors would experiment with hotter/colder plugs. Doesn't refer to providing a hotter or colder better spark but rather the designed heating/cleaning cycle of the plug. Again it's been 40-50 years ago so I may have this backasswards, but IIRC some of the mega built street motor guys who dealt with constant slow city traffic would run hotter plugs to keep them from loading up/fouling and the hwy fliers ran cooler plugs for efficiency. Yeah it's a long shot but I'd research it for your extreme load and slow speed conditions. On a side note: with NGK plugs the numbers 6,8 etc. The smaller the number the hotter the plug unlike other brands where the bigger the number the hotter the plug. In the sand traps if your plugs aren't fouling now I wouldn't bother.If you shut down in the sand and let it cool offfor 15-20 minis your power restored for at least a little while? If not prolly not an over heating issue.
I could see maybe a different cam with a longer duration on the exh valve helping the sand power loss thing but I'd check with Terry on that theory before buying/installing a different cam.
If you're sure the motors is losing power from running too hot an oil cooler with good syn oil should help some. But...at your low air flow speeds you'll need to also add a fan to the oil cooler. At low air flow speeds w/o a cooling fan it's just a hot oil storage reservoir.
I've seen but no experience with folks who live with daily traffic jams add switched computer fans on top of their jugs to prevent over heating. Seems to help? Ok, enough of my goofy thoughts for now. Best of luck to ya.
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Re: Best Tune for Hot Running?

Post by BinDerSmokDat » Thu Feb 06, 2020 2:38 pm

windmill wrote:
Fri Jan 31, 2020 12:41 pm
Bogging down under high load at low speeds is usually a sign of being too rich. I would try dropping the needle a hair, and retarding the ignition ever so little.
This is my thought.
While I don't pull the plugs right after bogging down, they definitely aren't lean.
Even when I've done long stretched of pavement and checked they aren't lean.
Consistently greyish-black but not oil or carbon fouled.
I'm running richer jets than stock (exact numbers escape me at the moment) maybe a couple of sizes up on both.
I'll try to find jet sizes as it will still be a week or so until i dig into the carbs.

I shimmed the stock needles way back in 2010 or 12011, so I should probably check those as well.
I have heard of them wearing, but maybe that was aftermarket needles?

Interesting comment about the high octane because I've been putting in higher octane gas the last few times off-roading, with exactly that thought, "I'm going to be running hot, higher octane can't hurt."
I've also tried to only use Top Tier gas to hopefully keep the intake valves clean. The last ride where I had the most problems was both high octane (92 or 93) and Top Tier. So I'm thinking it's more likely tune related than fuel related.

Oil cooling is an interesting point as I have added a skidplate and a deep sump, but removed the cooling fins.
I've only ever run dino engine oil because it gets changed so frequently, I'm not sure synthetic would be a benefit.
I'm not monitoring CHT but oil hasn't appeared overly hot or damaged.
Before the oil pan and skidplate change, after a weekend of off-roading it would smell strong and burnt.
Now it's fine.
But I think that is capacity related, as I've actually blocked the pans ability to cool.

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Re: Best Tune for Hot Running?

Post by BinDerSmokDat » Thu Feb 06, 2020 3:01 pm

Went back and found my jets in an old post from 2014...I've been through several exhaust set-ups including converting to a Y-pipe since then...

Stock from factory
Main 122
Idle 40

Windmill box and Stock exhaust (ran way too rich)
Windmill box and Hardly cans no mid pipes (still rich)
Main 132.5
Idle 45

Current Windmill box, raceway Y-pipe, into fence pipe into single Hardly can(a little rich)
Main 125
Idle 42

So it looks like I should try going back to stock.
(Now where'd I put that lil ziplock full of jets and carb rebuild parts?)
And just had a thought...double check that air filter, last time I played in sand it was pretty plugged.

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