The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Melena on April 12, 2009, 10:36:55 PM
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Okay, so this is a topic that's probably been beat to death. But, I'm still wondering about this.
My right carb has had a leak when the pet cock is left on after stopping. Supposedly that was taken care of last year when it had its big service. Today was the first time I've had her out since last fall. I turned on the petcock while I was getting my helmet and gloves and stuff on so the carbs would have a chance to get filled up before I got ready to start her up.
I had just gotten my helmet on when I smelled gas and there was a big puddle of gas under the bike. Petcock got turned off quickly. I could see where the gas was coming from - the back of the carb. Almost like it was coming out of the fuel hose to the carb. Got myself together and got the bike out of the gate and onto the pavement before I turned the petcock back on. Took a few times to get her started and I sat there watching the carb but there was no more leak. Bike started up and I had no problem. After I got gas and got on the road and got her up to speed there were a couple of backfires while going up a hill. Don't know if that is part of what's going on.
Before I headed back for home, we turned the petcock on while it sat there and checked out the carb for about 5 minutes. It didn't leak even 1 drop.
Did the hose dry out while it sat for the winter and that let the gas through? Maybe there was a dry gasket? When I had the full service by the dealer last year I think he put in new floats, so I don't think that's the problem. Maybe something was just stuck and once the gas got in there it unstuck?
One good thing that came out of this. There was a weed in the crack in the concrete right under the bike, and the gas flowed in there. When I got home the weed was a goner.
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Chances are the float needle was just temporarily stuck, came good again after a jiggle, the old petrol would have dried it in place if the bike had not been moved. (possibly)
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I tend to agree with Landlubber - I find a similar problem with my /2 floats sticking after sitting for a long time. Once the bike is running the vibration will shake the carb and loosen the float so the problem disappears. Back fires COULD have beed caused by the carb running rich - you may want to check the spark plug to see if it is fouled. Best bet is to keep riding all year - after all you are in sunny California!!!
ps - glad you got rid of the weed in your driveway.
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How old are the fuel line. Even if the fuel line in farely new the line could be coming apart. I have had a fuel bowl with a pin hole leaking.
Don
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One thing to be aware of is the percentage of ethanol in our fuel now is more aggressive on deteriorating rubber bits like the inside of the fuel line, so it might not be a bad idea to consider replacing all the rubber fuel lines on the bike every couple years.
I try to always put in a good amount (about 2X recommended) of fuel stabilizer into a full gas tank prior to long term storage (anything where the bike sits unused for a month or more) and make sure that I run the bike to get the mixed fuel/stabilizer into the whole system/carb passages.
I then drain the float bowls and figure if there is any gas left it has the stabilizer in which should ideally prevent any varnish formation and stickiness. Have never had a stuck needle or float in any bike since I've started doing this. the formation of varnish is less likely to occur in cold conditions (below 32F) than in hot conditions (above 65F).
I think that your float may have been just temporarily stuck down and freed themselves with fresh gas (solvent) and vibration. Keep an eye out for the condition to re-occur in the coming weeks and if it does then you may have to do some disassembly&cleaning.
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I'm thinking along the lines of Landlubber and Drewboid. The fuel line was put on brand new last year. I had that done as part of the major servicing I had done.
Riding all year? Well, I always plan on it. That's why I forget to put Stabil in the tank and empty the carb bowls. I always think I'll be going for another ride and then it gets cold and starts raining. I don't have a garage, just a bike cover. And I get like a grumbly bear in the winter and start hibernating. The bike then sits while I wait for a nice day for a ride. This is Northern California after all. Not freezing cold - 30 to 55 F range during the winter - but wet!
nhmaf Mike - You've got a great routine there. I'm going to have to learn my lesson and do that next year. I try to learn something new every year.................uh, every ride! ;)
Thanks for all your ideas. I'll keep an eye on it, but I think it's taken car of now.
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Interesting info.. I have a R60/6 in the tahoe area that I ride every early spring .. 2 years ago I left it with Stabil in it & returned the next spring to massive leaking fuel lines ( they were new), had to replace them all.So it makes me wonder what the deal is with that stuff.... or is it the new gas with ethenol, any thoughts?
Thanks, Bill
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Justin has a good alternative almost clear hose that he really likes.
I'm afraid I'm too anal to go without my black braided hose... :-/
;)
I don't know the name of it, but he will pop in here, I am sure!
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Bill,
I am pretty sure that it is the ethanol that did it to you - I've been using Stabil for over 15+ years now in all my motorcycles, lawnmowers, chains saws, woodsplitter and snowblower and it has never caused a problem with fuel lines or carbs in any of them. But, since the reformulation of the petrol with ethanol we've had to replace a friends fuel lines in his bike and in his ATV in the past 2 years, and they weren't old fuel lines to begin with - found tiny chunks of rubber in the carb bowls
and blocking a jet.
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What I have used is from Aircraft Spruce:
0585-071 POLYURETHANE TUBE 0585-071
This has been on my '81 R100 for almost 4 years, and although it is perfectly clear when first installed it turns brown with age. Although it turns color it is still pliable and does not seem to be brittle in any spots I've scrutinized...
I have since used it on all of our bikes.
It appears they now carry Bing alcohol resistant fule line, which I might try, and it is cheaper than the clear stuff:
05-00500 BING ALC RES FUEL LINE 1/4X3/8