Bing sweating!
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Pierre
Bing sweating!
Is it normal that when the petcock is first turned on befor a run that the idle air screw covers start to sweat? The petrol evaporates fast enough so that dropplets are not formed which would otherwise drip petrol on the floor. Also, when priming is done for about 3 seconds, dripping starts momentarily and continues until the petrol gets back to it's normal level...is this typical. Also, when the bike is placed on the sidestand with the petcock open (I have not tried this since I have removed the sidestand for S/C riding), would gas start dripping down the carb that is on the sidestand side? I am new to these Bings and have never seen this happen on AMAL's!
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Pierre
Re: Bing sweating!
Looking through service bulletins I have found out that BMW raised the petrol level of the float bowls by 4mm in June 1968. This was done in order to respond to hard starting and low top speed with BMW's equipped with new micro star cartridge air filters and lever tops. The carbs had numbers 1/26/91-92 as opposed to the ones I have 1/26/75-76. I suspect that since I put the lever tops on mine, the configuration of the parts and the older style carb does not go well with the latter as the 91-92 carbs were probably designed a little different in order to cope with the higher fuel level. The slide, main jet and needle jet were also different!
So the way I see it, is that to remedy my leak problem on my 75-76 carbs, I must bend the tab down to lower the float level or add another 3 washers between the tab and the float........CAN ANYONE CONFIRM THIS?
So the way I see it, is that to remedy my leak problem on my 75-76 carbs, I must bend the tab down to lower the float level or add another 3 washers between the tab and the float........CAN ANYONE CONFIRM THIS?
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Bruce Frey
Re: Bing sweating!
Hi Pierre, I'm no expert on carbs, but my R6 has Bings from an R50 on it instead of Amals (yes...the floats are inclined). Once I put new gaskets and float needles in, they are as dry as a bone unless I overprime. Four seconds works best for my bike. I can leave the petcock on with the engine off without any leakage. Would you happen to have a pair of Amal 276 laying around that you're not using?
Good luck
Good luck
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Pierre Michaud
Re: Bing sweating!
Thanks again Bruce. The last time I saw AMAL 276's was on my BSA Royal Star which I sold 12 tears ago. It's still on the road and belongs to a Blue Angel RCMP retiree. I am not getting much response to my problem...probably one of those "Why me?" problems.
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Drew Daniels
Re: Bing sweating!
Dripping after priming and when on the sidestand seems to be normal. The fuel level in the float bowls is almost level with the idle screw overflow. When the level rises as it does when primed or when on hte sidestand the fuel overflows.
Drew
Drew
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Pierre
Re: Bing sweating!
Thanks for confirming my fears! However, if you look at one of my responses in this thread, I believe I have found the reason why my carbs leak at the air idle screw. If it isn't then I give up. It seems odd to me that BMW would put a carburettor on their machines that is prone to leaking in this way!
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Peter Schildhause
Re: Bing sweating!
I have the 1/26/75-76 carbs on my bike with the same problem. I have lever tops and
have not contemplated trying to fix the problem. Let me know what solution you come
up with and tell me too why we have these odd carbs.
have not contemplated trying to fix the problem. Let me know what solution you come
up with and tell me too why we have these odd carbs.
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Pierre
Re: Bing sweating!
Hello Peter,
Well, I am now encouraged to find out I am not the only one with this problem! I suspect that when Bing came out with the new lever tops they also redesigned the carbs slightly. Our carbs were made to fit the original tops. I was recommended to change my tops for the lever type because my old top/float needle seat leaked and was told that the lever tops were much better. However, they neglegted to tell me that the float level would be 4 mm higher. At this height, the petrol level is at the same level as the air screw and this is why I am getting weeping and dripping. It also prevents me from balancing the carbs as the gas is being sucked in with the air at the idle air screw! I am waiting for someone to confirm my suspicions at which time I will either bend the tab or add some washers to lower the level of the floats. I will let you know one way or the other.
Well, I am now encouraged to find out I am not the only one with this problem! I suspect that when Bing came out with the new lever tops they also redesigned the carbs slightly. Our carbs were made to fit the original tops. I was recommended to change my tops for the lever type because my old top/float needle seat leaked and was told that the lever tops were much better. However, they neglegted to tell me that the float level would be 4 mm higher. At this height, the petrol level is at the same level as the air screw and this is why I am getting weeping and dripping. It also prevents me from balancing the carbs as the gas is being sucked in with the air at the idle air screw! I am waiting for someone to confirm my suspicions at which time I will either bend the tab or add some washers to lower the level of the floats. I will let you know one way or the other.
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rolf
Re: Bing sweating!
hallo,
I am not sure at what type Bing needs a small metal(washer?) ring, which you have to put on the top of the floater, but as I read your problems, it seems that if you put the new type of lever tops on old carburettors, you have to take this metal ring to shut the fuel earlier(I have to look at home(if you are interesting), how thick these ring was, if it was roundabout 4mm high, that was it).
But to answer your former question:
if the fuel does not leave the Bing through the airsrew(normally it should not leave, certainly) it would run into your cylinder and wash your oil inside the cylinder away(and you never saw it, but only feel it[when the engine broke down]).
rolf
I am not sure at what type Bing needs a small metal(washer?) ring, which you have to put on the top of the floater, but as I read your problems, it seems that if you put the new type of lever tops on old carburettors, you have to take this metal ring to shut the fuel earlier(I have to look at home(if you are interesting), how thick these ring was, if it was roundabout 4mm high, that was it).
But to answer your former question:
if the fuel does not leave the Bing through the airsrew(normally it should not leave, certainly) it would run into your cylinder and wash your oil inside the cylinder away(and you never saw it, but only feel it[when the engine broke down]).
rolf
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Pierre Michaud
Re: Bing sweating!
Hello Rolf,
I purchased the new lever top cover with the guide needle and the washer that was offered to me by Mark. I need to remove the tops to see how thick it is but do not want to smell gasoline going into work this morning. It is pretty close to 1 mm thick. This is why I was saying I could put 3 more washers to make up the 4 mm (It is part #13 11 1251394 with no indication of thickness in the auxiliary catalogue). So you think that 4 mm washers are available? I would like someone to confirm that adding the proper washer and or bending tabs is ok, because at this moment, I feel that I am the only one with this problem and would like to get to the end of the story! I do not believe that Bing or BMW intended their carbs to leak this way. When I put my bike on the sidestand, the carb on that side should not leak and standing still on the center stand, it should not "sweat" at the air idle adjusting screw!
Thanks again for your input
Pierre
I purchased the new lever top cover with the guide needle and the washer that was offered to me by Mark. I need to remove the tops to see how thick it is but do not want to smell gasoline going into work this morning. It is pretty close to 1 mm thick. This is why I was saying I could put 3 more washers to make up the 4 mm (It is part #13 11 1251394 with no indication of thickness in the auxiliary catalogue). So you think that 4 mm washers are available? I would like someone to confirm that adding the proper washer and or bending tabs is ok, because at this moment, I feel that I am the only one with this problem and would like to get to the end of the story! I do not believe that Bing or BMW intended their carbs to leak this way. When I put my bike on the sidestand, the carb on that side should not leak and standing still on the center stand, it should not "sweat" at the air idle adjusting screw!
Thanks again for your input
Pierre