Balancing Carbs , red hot header... smoke!

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glacoste
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Balancing Carbs , red hot header... smoke!

Post by glacoste » Fri Jun 28, 2019 7:54 am

Good Morning all...
So I was ready to balance my carbs this morning and all was going good. Had my fresh battery installed in the Twin Max with it all connected to the carbs.
Started motor and calibrated twin max as per instructions.
Started to lower my rpm's with a 1/4 turn from right carb to left carb. All looked good.
Motor had been running about 4 mins when I noticed small amount of smoke rising from the left cylinder along with the left header exhaust starting to get cherry red.
Went ahead and shut it down to cool off and consult the collective.
Thanks for any input.
2013 Gear-up
Mains: 130, Idle: 42, Needle: 0 shims
stock exhaust no cats
23927 km and counting

on2wheels52
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Re: Balancing Carbs , red hot header... smoke!

Post by on2wheels52 » Fri Jun 28, 2019 8:21 am

Perhaps run a fan in front of the bike?
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Re: Balancing Carbs , red hot header... smoke!

Post by harryball » Fri Jun 28, 2019 8:31 am

Are you tweaking the idle screw, or the air mixture screw? If the Jets are right and the air mix is set right, should take longer than 3 or 4 minutes to get too hot. I always ran mine and balanced the engine while it is hot. I'd run a couple of minutes, turn off for a couple and repeat if needed. Never had an overheat issue on either the 2008 or 2010 unless they were running too lean.
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Re: Balancing Carbs , red hot header... smoke!

Post by Lokiboy » Fri Jun 28, 2019 8:41 am

One, is you’re running 4+ minutes without airflow over the cylinders.

As harryball said, you’re only adjusting the idle screw (on the side of the carb). Should only need to adjust one side to get them to match up. Doing anything else and you’re doing it incorrectly
2011 Gear Up - "Erika"
Yorktown, VA

Mains: 127, Idle: 40, Needle: 1 shim
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Re: Balancing Carbs , red hot header... smoke!

Post by jeffsaline » Fri Jun 28, 2019 8:55 am

In my experience the Twin Max is calibrated with the engine off and once the engine is running the sensitivity is set.

Fans should be blowing on both cylinders and the engine should be at operating temperature for the final adjustments.

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Re: Balancing Carbs , red hot header... smoke!

Post by Lokiboy » Fri Jun 28, 2019 9:36 am

In my experience the Twin Max is calibrated with the engine off and once the engine is running the sensitivity is set.
That’s how you do it. Turned it on, put it to max sensitivity, zero it out, turn it off. Bring your sensitivity down to zero. Turn on the engine, increase the sensitivity to see where the needle is pointing. Adjust the carb that is either reading too high or too low, depending on the RPM sound you’re looking for.
2011 Gear Up - "Erika"
Yorktown, VA

Mains: 127, Idle: 40, Needle: 1 shim
MKIII air filter
100,000 km and counting

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Re: Balancing Carbs , red hot header... smoke!

Post by glacoste » Fri Jun 28, 2019 9:47 am

Ok...
I now have fans... also adjusting only spring screws on side of carbs. Also twin max is all set.
One problem is I can't get enough slack from throttle cables which only gives me limited adjustment.
2013 Gear-up
Mains: 130, Idle: 42, Needle: 0 shims
stock exhaust no cats
23927 km and counting

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glacoste
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Re: Balancing Carbs , red hot header... smoke!

Post by glacoste » Fri Jun 28, 2019 9:58 am

One other question.
The idle adjustment screws located on the bottom of carbs are set to 1.5 from closed.
I have about 1500 rpm showing on my tach.
Could I disconnect cables and adjust to lower rpm?
2013 Gear-up
Mains: 130, Idle: 42, Needle: 0 shims
stock exhaust no cats
23927 km and counting

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Re: Balancing Carbs , red hot header... smoke!

Post by stagewex » Fri Jun 28, 2019 10:04 am

Do you know if your rig is running the stock jets set-up? And needle too?
Yes, besides the expected heat of balancing without a fan it's a possible lean situation. My '07 did that initially until I changed then. Dealers used to do it almost autonatically instead of hearing from complaining customers.
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Current Herd all running amok:
2019 Honda CRF450L (Elec Start)
2008 Vespa 150S (Elec & Kick Start)
2007 Ural Patrol (2WD, Elec & Kick Start)
2006 Honda "Big Ruckus" PS250 (Elec Start)
1991 Honda XR250L (Kick Start Only) *NOT running amok, out for Bottom & Top-End Rebuild.
1986 Yamaha BW200ES (Elec & Kick Start)

List what you "have", keep the others in your precious memory bank.

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Re: Balancing Carbs , red hot header... smoke!

Post by glacoste » Fri Jun 28, 2019 10:10 am

Don't know what size the jets are. Asked the previous owner, he doesn't know. I did clean the right carb yesterday. Looked at the jets, but did't see any markings.
2013 Gear-up
Mains: 130, Idle: 42, Needle: 0 shims
stock exhaust no cats
23927 km and counting

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Re: Balancing Carbs , red hot header... smoke!

Post by Lokiboy » Fri Jun 28, 2019 10:16 am

glacoste wrote:
Fri Jun 28, 2019 9:58 am
One other question.
The idle adjustment screws located on the bottom of carbs are set to 1.5 from closed.
I have about 1500 rpm showing on my tach.
Could I disconnect cables and adjust to lower rpm?
I’m going to guess you are new to Ural’s. When you get a chance read through the hammer and wrenching section, there is a wealth of information that might benefit you. You don’t need to read every topic. I recommend you read the topics starting at 2011 to 2013.

The carburetor adjustments have nothing to do with your RPM, with the exception of the idle screws on the side of the carburetor (only while at idle they are basically syncing the carburetor and it may sound like they’re adjusting the RPMs. You are, but again you’re only fine-tuning).

If you’re running at 1500 RPM and you want to bring it down you need to adjust your timing. In hammer and wrenching section there is a sticky that describes exactly how to adjust timing on a Ural
2011 Gear Up - "Erika"
Yorktown, VA

Mains: 127, Idle: 40, Needle: 1 shim
MKIII air filter
100,000 km and counting

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Re: Balancing Carbs , red hot header... smoke!

Post by VWK75S » Fri Jun 28, 2019 10:17 am

glacoste wrote:
Fri Jun 28, 2019 9:58 am
One other question.
The idle adjustment screws located on the bottom of carbs are set to 1.5 from closed.
I have about 1500 rpm showing on my tach.
Could I disconnect cables and adjust to lower rpm?
The Ural's made Maine a much bigger state.

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Re: Balancing Carbs , red hot header... smoke!

Post by Lokiboy » Fri Jun 28, 2019 10:18 am

Here’s a site with some good info

viewtopic.php?f=25&t=28897
2011 Gear Up - "Erika"
Yorktown, VA

Mains: 127, Idle: 40, Needle: 1 shim
MKIII air filter
100,000 km and counting

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glacoste
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Re: Balancing Carbs , red hot header... smoke!

Post by glacoste » Fri Jun 28, 2019 10:53 am

Yes.. new to Urals. Never had a motorcycle before.
I've always liked Urals. Looked at photos for 5 years before finding this one.
Thanks for all the info. Got some research to do.
2013 Gear-up
Mains: 130, Idle: 42, Needle: 0 shims
stock exhaust no cats
23927 km and counting

stagewex
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Re: Balancing Carbs , red hot header... smoke!

Post by stagewex » Fri Jun 28, 2019 10:57 am

glacoste wrote:
Fri Jun 28, 2019 10:10 am
Don't know what size the jets are. Asked the previous owner, he doesn't know. I did clean the right carb yesterday. Looked at the jets, but did't see any markings.
You'd have to possibly take the jets out to see and identify them. Or turn you carb upside down to read the markings. At some point this would not be a bad thing to do so at least you know. If you are only getting red-pipes because of the balancing then you don't have a real problem anyway. If even the previous owner (original owner?) doesn't know then maybe a possibility they are stock even now... 6 years later. Not critical but had to be set-up that way to pass USA emissions. As far as I know this is what they came over as stock:

Stock Main Jet from the factory was 125
Stock Pilot Jet from the factory was 38

Yeah, parking with the my engine running while I was going over to open my garage door at night, I got the red-pipe effect. Then I did the "Let It Breath" mod:

Main Jet= 130
Pilot Jet= 45
Needles shimmed with 2 washers each.

Eventually I lost the cats too. All easy stuff to do with a carbie and why when the first EFI bikes come out I was not impressed, very lackluster back then with the first software map. This combo for me gives great throttle response. But you can play round with any number of combinations which is the beauty of tinkering with a carb bike. No mapping.
Stagewex

Current Herd all running amok:
2019 Honda CRF450L (Elec Start)
2008 Vespa 150S (Elec & Kick Start)
2007 Ural Patrol (2WD, Elec & Kick Start)
2006 Honda "Big Ruckus" PS250 (Elec Start)
1991 Honda XR250L (Kick Start Only) *NOT running amok, out for Bottom & Top-End Rebuild.
1986 Yamaha BW200ES (Elec & Kick Start)

List what you "have", keep the others in your precious memory bank.

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