Diaphragms

[Adrian]

Hi there - I'm having difficulty finding a supplier of OEM diaphragms for my Bings. I have read so much that strongly warns against buying non - OEM parts. Any help would be great thanks ....... Adrian

[Tony Smith]

Hi there - I'm having difficulty finding a supplier of OEM diaphragms for my Bings. I have read so much that strongly warns against buying non - OEM parts. Any help would be great thanks ....... Adrian

The best advice is to ignore such warnings, at least as regards diaphragms.  high profile suppliers like motobins have a long and complaint free history supplying non-OEM parts. I have never bought genuine diaphragms in 37 years of airhead ownership, not only on my own bikes, but also my wife's, numerous friends etc. Just buy a set from motobins and don't worry about it.

[Adrian]

Hi Tony - are you saying that you have used non OEM diaphragms in an old Airhead that have been supplied by Motobins? I am cautious because almost every forum I have been on recommends OEM parts only. Perhaps its just caution by everyone but when the World Wide Guru Snowbum recommends in very large red lettering that ONLY OEM is the way to go I tend to take notice. If you have personal experience of non OEM diaphragms working well - can you let me have the part number that you have used on the Motobins site. I will be very grateful . Thanks ......

[montmil]

Adrian, It's your decision, time, money and results. Choose wisely.

[Bob_Roller]

I don't know if this is the case today, but I know a few members that purchased after market diaphragms and had issues with them .
The material that was used, was thicker than the OEM parts .
If I remember correctly, Stromberg was the manufacturer / supplier of this part .
UK and US members had problems .
I believe that one member here, Lucky Lou had the issues, hopefully he can comment on this .
This was about 5 years ago, or so, have not heard of this issue since then .
OEM parts are pricier than pattern aftermarket parts, no dispute there, especially for what you are getting  !!!!!

[nhmaf]

+1 with Bob Roller - there have been issues with some pattern parts, and I also seem to recall it was Stromberg that was one of significant complaint.   It is also possible that Motobins might have changed their supplier - or gotten their supplier to change the mold. I don't know.   The thickness difference of the rubber made a dramatic difference in the flexibility/stiffness of the diaphragm resulting in improper needle positioning.   I always go to Bing for the Bing related parts and consider it to just be the price of knowing the part will work without question.   Other things, I do consider aftermarket/other vendors for (but not oil filters - that is another area where I've had too many crushed aftermarket filters versus the Mahle/factory filters).

[Adrian]

Okay thanks guys - Motobins advertises a Bing complete seals kit that includes the diaphragms so that is probably the way to go. If its Bing then it should be okay I reckon .....

[Adrian]

+1 with Bob Roller - there have been issues with some pattern parts, and I also seem to recall it was Stromberg that was one of significant complaint. It is also possible that Motobins might have changed their supplier - or gotten their supplier to change the mold. I don't know. The thickness difference of the rubber made a dramatic difference in the flexibility/stiffness of the diaphragm resulting in improper needle positioning. I always go to Bing for the Bing related parts and consider it to just be the price of knowing the part will work without question. Other things, I do consider aftermarket/other vendors for (but not oil filters - that is another area where I've had too many crushed aftermarket filters versus the Mahle/factory filters).  

Just a small P.S. to nhmaf - if you have gone direct to Bing would you let me have the web address please. Before I order from Motobins I would like to check the web site - thanks ......

[Red_Hen]

Adrian - if it were me, I'd purchase from Bing Agency direct - I believe they have an office in UK as well as US - here is there link:

http://www.bingcarburetor.com

Expensive but inexpensive to mail and no doubt they all work on your carbs!

[Tony Smith]

Hi Tony - are you saying that you have used non OEM diaphragms in an old Airhead that have been supplied by Motobins? I am cautious because almost every forum I have been on recommends OEM parts only. Perhaps its just caution by everyone but when the World Wide Guru Snowbum recommends in very large red lettering that ONLY OEM is the way to go I tend to take notice. If you have personal experience of non OEM diaphragms working well - can you let me have the part number that you have used on the Motobins site. I will be very grateful . Thanks ......

Adrian - that is exactly what I am saying.

Snowbum has wonderful knowledge and I am very glad that he chooses to share that knowledge so willingly (and in insomnia curing detail), but he is not infallible and he is sometimes simply wrong.

I also need to clarify that it is only in recent decades that I have purchased non-OEM diaphragms from motobins. Prior to that I used to buy Stromberg parts from my local carb rebuilder (a trade/calling/business model that has failed utterly in the past 15 odd years. I have never, ever had a problem with a non-oem diaphragm and I never expect to for reasons that I could bore you with to almost Snowbum extremes.

[Adrian]

Hi Tony and thanks - it seems that Munich do sell genuine OEM after all - a chap on an Airhead Facebook site has helped me find them on there. They are very expensive but I'll be happier with genuine I think. Assuming they get some more stock soon - of course they are out of stock just cos I want them lol lol lol    

[Barry]

I haven't replaced the diaphragms on my current bike so this is mostly speculation but I would be inclined to give the non OEM ones a try. I have owned vehicles with Stromberg CV's and the diaphragms never gave me a problem. I'm with Tony on not necessarily taking as gospel all Guru pronouncements particularly when the reasons are not fully explained. We could do with hearing the specific issues that users have had with non OEM diaphragms. I also remember Lou having a problem but can't think what it was exactly.

The potential problems with non OEM might be:

Rubber not compatible with fuel - seems unlikely but could obviously rule them out or shorten their life.

Thicker material changes carb operation - Unless they were extraordinarily thick all I can see happening is s slight loss of responsiveness due to some additional damping effect which might even be a good thing for those carbs that don't have springs fitted.

[Adrian]

Thanks Barry - having had a reply from Toni that was very helpful - I'm putting together an order from Motorworks tonight - they have a complete kit including needle and jets with all the rubbers so that will be fine I reckon .....