Gas mileage tanked... fuel leak?

Are ya having a problem with your rig? We'll try to help. Share your tech tips and experiences here. Dr. Billy Glaser, author of the "Unofficial 750 Ural Service Manual" site myural.com, is moderating this section.
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Re: Gas mileage tanked... fuel leak?

Post by gobium » Sun Jul 01, 2012 12:54 pm

My BMW1150 and your 650 don't have pet cock because they ate fuel injection set up.

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Re: Gas mileage tanked... fuel leak?

Post by URAL CT » Sun Jul 01, 2012 12:56 pm

Dachary..,..no question is stupid...not asking is!
All my posts relating to tips are all road touring experiences on my part and how I dealt with the issue. I'm no expert & I can prove it. My bet with your mileage issue is 1. it's still breaking-in, 2. your air filter is clogged up & 3. you have a pool of oil in the air cleaner. All 1st time maladies. Same when I got the rig new in 07, mileage was low 20s & the air cleaner seem to pool with oil, so I routed the hose to the outside. After 10,000 kms, I started hitting 33 to 36 mpg & it's been like that since. Just ride it, :moto: :moto: :moto: enjoy & carry some spare gas :D
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Re: Gas mileage tanked... fuel leak?

Post by gobium » Sun Jul 01, 2012 1:00 pm

I got awsome gas mileage on my BC, because I got rid of factory set up. My filter now is 3 times bigger and better.

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Re: Gas mileage tanked... fuel leak?

Post by Darkblood » Sun Jul 01, 2012 1:24 pm

On a vacuum petcock if it looses vacuum you no longer get gas to the carbs so no it wouldn't give you crappy mileage. All the vacuum petcock is is a valve that open up to let fuel flow through it when a vacuum is applied to a diaphragm.

I still think someone borrowed some of your fuel when you weren't looking.
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Re: Gas mileage tanked... fuel leak?

Post by Lokiboy » Sun Jul 01, 2012 3:02 pm

My two cents - I have no idea why your losing gas? A real help, aren't I. :D IMHO, Your bike is too new and you haven't been off roading to have affected the air filter. The small amount of overflow that spills on to the air filter is minimal and you wouldn't notice any gas mileage impact. But you must have a leak somewhere?! :? If it's not the peacock, and I'm not sure it is because that much gas going into the jugs would cause a vapor lock and you'd have already found out the hard way what happens when you don't manually kickstart a few times before you turn on the ignition and just electric start off the bat (if locked, you can't move the kick start and a major failure of the electric starter) So, that leaves a lose fitting or a small crack in one of the fuel lines. But, from what you describe, that would be a lot of gas and you'd see or smell it. Stupid suggestion, but are you consistent as to the level you fill your tank? For a new bike you've been having some interesting problems. :o and this is a very perplexing problem.

As a side note, and once you find the disappearing gas, to improve mileage, really learn how to adjust your carbs at both idle and with throttle. I can't swear to it, but I've always thought it was key since i don't do anything special, yet I've always been around 33 mpg, although I keep my bike under 45 mph and on pavement for the most part, but even long distance at 55+ it stays around 29 mpg.

Good luck and good hunting :)
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Gas mileage tanked... fuel leak?

Post by Dachary » Sun Jul 01, 2012 8:31 pm

Ok, the day sorta got away from us so I didn't get a chance to check the petcock vacuum or pull the air filter. I did pull the plugs and they look beautiful - they look like an almost new bike that's starting to get a beautiful Carmel/coffee color to them, and it's even on both sides, so I'm happy with that.

I've got some huge deadlines this week at work so I might not get a chance to screw with it again... maybe if I do good tomorrow and Tuesday with work I can relax on the 4th and grab the bike and check the air filter/vacuum.

The other problem I encountered today was the engine has been starting to run a bit like it did the day I picked it up and brought it home from the dealer. After running for 15-20 minutes I'm having problems with it sounding like it wants to die at idle (at stop lights, in neutral) and lacking power when I go to pull away. In other words - exactly the crap it was doing the day I brought it home from the dealer which they said was due to the breather elbow melting and constricting the airflow, etc.

Checked the breather tube elbow and it's just fine. I checked the oil this AM and it was a bit low (about 3/4 to the full mark) - we've been having to top it up after running at highway speeds - but I topped it up before we went out so it isn't low on engine oil. The only other thing I can think is that maybe the valves are really tight and when the engine heats up and expands, the valves don't have enough clearance?

It was around mid-90s here today, I was driving in regular city style - go for a bit, get up to 20-35mph, hit a stop light, stop, wait to go again... Not sitting around for a long time or anything. But I don't believe it's normal for a Ural to have problems in regular operation in mid-90s or you folks who live in Florida, Texas and AZ would never be able to ride them!
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Re: Gas mileage tanked... fuel leak?

Post by cdscoot » Sun Jul 01, 2012 8:47 pm

Dachary wrote:Ok, the day sorta got away from us so I didn't get a chance to check the petcock vacuum or pull the air filter. I did pull the plugs and they look beautiful - they look like an almost new bike that's starting to get a beautiful Carmel/coffee color to them, and it's even on both sides, so I'm happy with that.

I've got some huge deadlines this week at work so I might not get a chance to screw with it again... maybe if I do good tomorrow and Tuesday with work I can relax on the 4th and grab the bike and check the air filter/vacuum.

The other problem I encountered today was the engine has been starting to run a bit like it did the day I picked it up and brought it home from the dealer. After running for 15-20 minutes I'm having problems with it sounding like it wants to die at idle (at stop lights, in neutral) and lacking power when I go to pull away. In other words - exactly the crap it was doing the day I brought it home from the dealer which they said was due to the breather elbow melting and constricting the airflow, etc.

Checked the breather tube elbow and it's just fine. I checked the oil this AM and it was a bit low (about 3/4 to the full mark) - we've been having to top it up after running at highway speeds - but I topped it up before we went out so it isn't low on engine oil. The only other thing I can think is that maybe the valves are really tight and when the engine heats up and expands, the valves don't have enough clearance?

It was around mid-90s here today, I was driving in regular city style - go for a bit, get up to 20-35mph, hit a stop light, stop, wait to go again... Not sitting around for a long time or anything. But I don't believe it's normal for a Ural to have problems in regular operation in mid-90s or you folks who live in Florida, Texas and AZ would never be able to ride them!
I think it is a matter of the air temp change. In hot weather you get better vapoization of the gas . Try turning your idle mixture screws in evenly on each side a bit. Turn in say 1/8 to 1/4 turn and see if you get improvement.Maybe a real expert will chime in.
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Re: Gas mileage tanked... fuel leak?

Post by Darkblood » Sun Jul 01, 2012 9:29 pm

I generally run regular in the bike but noticed on the days it's in the 90's the bike was acting sad. Just for giggles I upped the octane to 91 from 87 and it seems happier.

My bike also got sluggish when hot until about 5,000 km's and a few valve checks/adjustments. As has been said here millions of times loose valves are happy valves.
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Re: Gas mileage tanked... fuel leak?

Post by Niteblues » Sun Jul 01, 2012 10:24 pm

Dachary- have you adjusted the valves yet? After 2500kms, it certainly wouldn't be a bad idea to check them at this point.

Didn't you say you were running it in the rain? If so, your air filter may have gotten moist-ish. When that happens IME, the oil that was sprayed on the filter mixes with the water and makes a coagulated barrier to good air flow. It will never dry out on it's own until the gunk is removed and then allowed to air dry in the sun, so to speak.

I just rode about 225kms yesterday in 105F heat. The bike ran fine.
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Re: Gas mileage tanked... fuel leak?

Post by BRO » Sun Jul 01, 2012 10:50 pm

Have you checked your air filter yet.

Just replaced mine a few days ago & mileage dropped on the next tank use.
I over oiled the blue filter. Trying to have all the protection I can give it, I errored. Was at a regular 31-32 before & now 27-28. Have run two tanks & about to fill up again & still driving the same way since before the over oiling.

I have a new GU & am a bit of an anxious father, I mean owner. I listen to the start ups & even at the intersection while waiting for the light to change.

I'm glad to learn of another owner who shares the interest in the growth of ownership.
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Re: Gas mileage tanked... fuel leak?

Post by Dachary » Mon Jul 02, 2012 2:49 pm

Been running premium in the rig. We run premium in all our bikes. It doesn't cost us a whole lot more, and we met a couple in Peru whose BMW engines failed catastrophically - due to bad gas. I know that nothing we encounter here in the U.S. is likely to be anywhere near approaching the range of "bad gas" in Peru, where we got into the habit of using fuel additives, but the location has more to do with the cost than the grade of fuel. If we get out of the city, we pay less for premium than we would for low-grade here in the city.

Didn't get time to pull the air filter yesterday but I'll take a look at it when I get a chance - probably (hopefully) on Wednesday. I ordered a K&N last night and I'll probably put it in and use the Ural filter as a backup for hot swaps.

I still think the valves might be contributing to this. I've been waiting for the 2500km service to check them, which I'll probably still do. I'm only a week or two out from that service and so far the forecast is supposed to be in the low 80s, so I'll continue to listen and keep an eye on fluids and see how things change when I do valves/air filter. Also thinking of rejetting the carbs at that point. I've gotten a lot of conflicting advice - some people saying the stock jets are fine, and some people saying you really need to open up the jets to get the best performance out of the rig, etc. I've got some bigger jets but I'm pondering whether to install or just wait and see how things go after valves/air filter service.
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Re: Gas mileage tanked... fuel leak?

Post by Niteblues » Mon Jul 02, 2012 3:37 pm

Dachary,

The K&N breathes better than the Ural stock air filter. That modification alone may not justify larger jets, but if you remove the cats out of the muffls, and/or replace the muffs to a free-er flowing exhaust along with the K&N, the larger jets are likely to be more correct than the stock ones.

With just the K&N, you may have to adjust the idle jet screw (on the bottom of the carb, without removing anything). Typically that idle jet screw is between 1 1/2 and 2, maybe 2 1/2 turns out from a soft seat. After putting in the K&N, you should mess with that. If you have to adjust it to 3 or more turns out from the soft seat- it is time for bigger jets. IMO, you should check that idle jet screw now. Softly screw it in, while counting turns, until it seats- softly, it is brass. Then back it out to 1 1/2 turns on each side. Please report back what the settings were for each side to begin with- that may be contributing to your idling issues. I have found my settings different to each other and NOT at 2 turns out and have adjusted those darn screws often! They must vibrate out of whack or something. I also put a big dollop of dielectric grease up inside of the little hole where the screw is. That keeps debris out of there and *may* help keep them set to where I left them. But after water crossings and lots of dirt roading, there is always that dollop of grease up in there, so it can't be a bad thing...

With the K&N AND new mufflers, you would most likely have to adjust it to more than 3 turns out which would indicate the need for the larger jets.

It is not necessary to wait for the 2500kms to check and adjust the valves. Heck, it took me three or four times of adjusting them to become comfortable with doing it right. Either that, or in the beginning your adjustments do not last that long. Perhaps once the rig is fully broken in, the valves do not get out of adjustment as often. I do think, however, that if the valves are too tight it is not a good thing to keep running it that way.
Scott

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Re: Gas mileage tanked... fuel leak?

Post by elizilla » Mon Jul 02, 2012 5:28 pm

The valve adjustment only takes a half hour or so - it's really easy compared to any modern bike I have owned. You don't have to drain the oil, there's no coolant, and you don't have to take half the bike apart to get to them. You can have that cover off and check them in minutes, and if they're fine, you don't have to worry any more.
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Re: Gas mileage tanked... fuel leak?

Post by Lokiboy » Mon Jul 02, 2012 6:29 pm

niteblues59 wrote:Dachary,

The K&N breathes better than the Ural stock air filter. That modification alone may not justify larger jets, but if you remove the cats out of the muffls, and/or replace the muffs to a free-er flowing exhaust along with the K&N, the larger jets are likely to be more correct than the stock ones.

With just the K&N, you may have to adjust the idle jet screw (on the bottom of the carb, without removing anything). Typically that idle jet screw is between 1 1/2 and 2, maybe 2 1/2 turns out from a soft seat. After putting in the K&N, you should mess with that. If you have to adjust it to 3 or more turns out from the soft seat- it is time for bigger jets. IMO, you should check that idle jet screw now. Softly screw it in, while counting turns, until it seats- softly, it is brass. Then back it out to 1 1/2 turns on each side. Please report back what the settings were for each side to begin with- that may be contributing to your idling issues. I have found my settings different to each other and NOT at 2 turns out and have adjusted those darn screws often! They must vibrate out of whack or something. I also put a big dollop of dielectric grease up inside of the little hole where the screw is. That keeps debris out of there and *may* help keep them set to where I left them. But after water crossings and lots of dirt roading, there is always that dollop of grease up in there, so it can't be a bad thing...

With the K&N AND new mufflers, you would most likely have to adjust it to more than 3 turns out which would indicate the need for the larger jets.

It is not necessary to wait for the 2500kms to check and adjust the valves. Heck, it took me three or four times of adjusting them to become comfortable with doing it right. Either that, or in the beginning your adjustments do not last that long. Perhaps once the rig is fully broken in, the valves do not get out of adjustment as often. I do think, however, that if the valves are too tight it is not a good thing to keep running it that way.
Scott's way is the best. However, Being lazy, and since the settings are standard ( yes, a bad assumption) I just turned the air/fuel screw 1/4 CCW to enrich the mixture - solved my popping/farting issues. I ended up having to add another 1/4. So with that and two shims on the needle, I've left everything else the same. I think adding larger jets will lower your gas mileage - others can chime in.

Have fun.
2011 Gear Up - "Erika"
Yorktown, VA

Mains: 127, Idle: 40, Needle: 1 shim
MKIII air filter
80,000 km and counting

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Re: Gas mileage tanked... fuel leak?

Post by Niteblues » Mon Jul 02, 2012 8:03 pm

Lokiboy wrote:...
I think adding larger jets will lower your gas mileage - others can chime in.
...
Nope. Not when they are installed when needed. Better running engine and all...
Scott

2004 Ural Patrol

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