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Warning re fuel filters


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Got a bad batch of fuel recently, filled both Urals at the same time and when each got down towards switching to reserve 3 of 4 of the float needles jammed and flooded the engine big time. Whilst fixing the first one on the side of the road enough fuel ran into the cylinder to prevent the engine from turning over. Luckily I had shorted the plugs out or could have had major engine damage. 9 other bikes that filled up locally had fuel problems also.

Fitted filters in the lines of each carb today, so hopefully the problem is solved. Will be draining the tanks (again) as soon as the fuel level drop a bit....

 

Also, put pin stripes on the bikes and I reckon they look better, takes away the plain look of the front of the chair..

 

 

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Got a bad batch of fuel recently, filled both Urals at the same time and when each got down towards switching to reserve 3 of 4 of the float needles jammed and flooded the engine big time. Whilst fixing the first one on the side of the road enough fuel ran into the cylinder to prevent the engine from turning over. Luckily I had shorted the plugs out or could have had major engine damage. 9 other bikes that filled up locally had fuel problems also.

Fitted filters in the lines of each carb today, so hopefully the problem is solved. Will be draining the tanks (again) as soon as the fuel level drop a bit....

 

Also, put pin stripes on the bikes and I reckon they look better, takes away the plain look of the front of the chair..

 

 

post-1679-1232599612_thumb.jpg

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Got a bad batch of fuel recently, filled both Urals at the same time and when each got down towards switching to reserve 3 of 4 of the float needles jammed and flooded the engine big time. Whilst fixing the first one on the side of the road enough fuel ran into the cylinder to prevent the engine from turning over. Luckily I had shorted the plugs out or could have had major engine damage. 9 other bikes that filled up locally had fuel problems also.

Fitted filters in the lines of each carb today, so hopefully the problem is solved. Will be draining the tanks (again) as soon as the fuel level drop a bit....

 

Also, put pin stripes on the bikes and I reckon they look better, takes away the plain look of the front of the chair..

 

 

post-1679-1232599612_thumb.jpg

 

i've seen inline filters on some urals, some say its a good idea, some say it restricts fuel flow? I have had inline filters on other bikes, so I guess I will give it a go and see for myself.

Thanks for the heads up.

sean

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They are not needed and do not prevent stuck float needles. Urals used to come with in-line fuel filters until just a couple years ago. Stuck floats and hydro-locking of cylinders (which has nothing to do with shorting out plugs) was still a common read about event on these forums.

 

In-lines will not prevent problems from contaminated fuel. Any particles small enough to go through the petcock filter will get past in-lines. Water, kerosene and other liquid contaminants are not stopped by bronze or paper filters either.

 

The factory ran test and found the petcock filter more than adequate. I did my own fuel flow tests and found the flow cut by approximately 25% when using in-lines. I ditched them years ago and never looked back.

 

Using them will not hurt anything, might cause some slight stumbling if you out strip the refill flow...might increase chances of holing a piston if the petcock screen gets plugged (under right conditions)...but in reality those instances will be rare.

 

Last, you'll now spend an inordinate amount of time staring at the air/vapor trapped in the one filter or the other while driving down the road...and plow into something.

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Hi Bill,

The part that made me put in the filters was the fact that in two days I had 3 carbs do the same thing, and other bikes had big fuel problems as well. Until then I though the petcock filter would do the job, now I'll have to do further investigation. The fact that it happened just before turning to reserve made me think whatever the contaminant was it wasn't water because I assumed it was on top of the fuel ???? I suspect now the problem may have been water because of the muck around the float needle and seat, and the traces of brown liquid in the bottom of the bowl. I'm draining the tank today so I'll see what comes out and post the results.

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Other than oil , any other contaminates are going to sink. If you are hitting the throttle heavy it will suck up the crud as the fuel level is sucked down.

 

Don't forget to drain the cross-over tube as that is where most of the sediment and water will go.

 

As an aside, a few years ago while goofing off in the swamp I ended up submerging the bike up to the gas tank in muck water for a couple hours until I could get it out. Long story short, I never cleaned the Keihins. Maybe 6 months later I decided to give them a good cleaning. The top of the diaphragms were caked with sand, the needle jets were caked with sand, every orifice was plugged with sand and the bowls had about 3mm's thick of debris laying in the bottom.

 

Engine ran fine, plugs looked fine, gas drained from carb. bowls looked fine. How them phuckers ran at all I'll never fathom. I could have made my own beach from the crap I cleaned out of those carbs. So my point is, it amazes me how so many folks get a microscopic bugger of crud in the carb and it stops functioning. Just makes you ponder how things work out. Maybe. :rolleyes:

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I have not looked inside the tank on my 96, but does anyyone KNOW if both outlets in the tank(reserve and normal) have a built in filter? I have seen bikes that did not have one on the reserve circuit. My 96 has inline filters, as does every gravity fed bike I own or have ever owned. I have always heard rumblings about restriction, but have never had an issue with it first hand. Just my .02.

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Got a bad batch of fuel recently, filled both Urals at the same time and when each got down towards switching to reserve 3 of 4 of the float needles jammed and flooded the engine big time. Whilst fixing the first one on the side of the road enough fuel ran into the cylinder to prevent the engine from turning over. Luckily I had shorted the plugs out or could have had major engine damage. 9 other bikes that filled up locally had fuel problems also.

Fitted filters in the lines of each carb today, so hopefully the problem is solved. Will be draining the tanks (again) as soon as the fuel level drop a bit....

 

Also, put pin stripes on the bikes and I reckon they look better, takes away the plain look of the front of the chair..

 

 

post-1679-1232599612_thumb.jpg

 

Picked these up today at MCA Sydney, re usable inline filter.

Think I will give them a try and see how they go.

Available in silver black blue also, $14.95 ea

post-8035-1232673062_thumb.jpg

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All the commie bikes I've seen had a metal gauze in the float bowl. This seems effective enough for me. Russian fuel taps are of notoriously pish quality. The ends of the stand pipe are often crimped over and the internal holes often don't line up. Fix these faults and you will quite probably notice a performance improvement. Add feul filters on top of a bad tap and you could end up with a holed piston. You will have to keep a good eye on the filter for contamination.

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Got a bad batch of fuel recently, filled both Urals at the same time and when each got down towards switching to reserve 3 of 4 of the float needles jammed and flooded the engine big time. Whilst fixing the first one on the side of the road enough fuel ran into the cylinder to prevent the engine from turning over. Luckily I had shorted the plugs out or could have had major engine damage. 9 other bikes that filled up locally had fuel problems also.

Fitted filters in the lines of each carb today, so hopefully the problem is solved. Will be draining the tanks (again) as soon as the fuel level drop a bit....

 

Also, put pin stripes on the bikes and I reckon they look better, takes away the plain look of the front of the chair..

 

 

post-1679-1232599612_thumb.jpg

 

Hi Graham,

Strips look Good, If I can Ask

Who Done them for You?

Regards David, Victor Harbor.

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I do not know about the newer vacuum cocks, but on the older petcocks the filter element slipped over the main tank stand tube and the hole for the reserve.

 

http://myural.com/petcock_service.htm

 

 

New ones have it too.

 

I have a 2007 bike. The petcock assembly is fitted with a filter inside the tank: cylindrical plastic guaze on a plastic frame.

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I installed two inline filters and found them to be restrictive to the full flow of fuel, rode from Turramurra over the mountains to Bathurst and noticed the difference going up. removed them and had a better ride homeward bound. Just my two cents worth. Went Bell Line both ways, great ride :biggrin:

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I installed two inline filters and found them to be restrictive to the full flow of fuel, rode from Turramurra over the mountains to Bathurst and noticed the difference going up. removed them and had a better ride homeward bound. Just my two cents worth. Went Bell Line both ways, great ride :biggrin:

I have been using the same type of filters for several years now without any problems. Maybe the newer petrol taps are not letting the fuel flow as fast?????????????

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To filter or not, same thing happens with or without a filter, without a filter, the standpipe can start to slowly clog, leaning mixture on that day you run hard, Ok you put filters on, they start to clog and they are less prone to flow 100% fuel in the first place, so suddenly you are faced with a steep hill, you had 60% flow and you now need the extra power, things lean out, the engine is hot and boom, holey piston. In either case, a flow check is the answer, pull the line at the carb, use a water glass, if it will put 5-6 oz in 15 seconds in that glass, you are good to go, wiser yet, check the flow on main and reserve, I used to know aerobatic pilot who would filter all fuel thru a chamois skin, as a clogged what ever, inverted 20 feet off the ground, will always ruin your day......Ken :biggrin:

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