Wed, 07/20/2011 - 01:03
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Can people give me their experiences with aftermarket carbs? I'm thinking about purchasing Mikuni 34mmVM pre-jetted carbs, but wanted to see if there were better options. Thanks.
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Tue, 08/09/2011 - 13:41
#2
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I like Mikuni's!
I have a 77 R75/7 that had miss-matched Bings, the numbers were not stock. They functioned ok but a little cold blooded. I switched to the Mikuni 32 and the starting improved and overall response is good. Have ridden them from sealevel to 12K feet with overall good preformance... The bike is currently in Denver and I plan to bring back to sealevel next month.
I am sold on the Mikuni's. I got my kit from Rocky Point Cycle. The install was easy.
I have saved the Bings for storage.
Fri, 08/26/2011 - 11:32
#3
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How much did the Mikuni's
How much did the Mikuni's run? I need to re-do my bings this winter and am debating on whether to just replace them and do the same with a lot of other "trouble' parts.
Fri, 09/02/2011 - 12:39
#4
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C'mon guys.... a jap carbs on
C'mon guys.... a jap carbs on a German bike ?? LOL !! kidding...
I would never replace the Bing with mikuni. for 2 reasons : re-do 2 bings is easy and less expensive than buy 2 new carb.
second, if you wanna run round slide carbs go with Dello'ORTO.
I personally like the Bings on a beemer no matter what !
just my 02.
Marco
Sun, 09/04/2011 - 13:46
#5
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I went to Mikunis on my R75/5
I went to Mikunis on my R75/5 after I rebuilt two sets of bings and as far as I'm concerned, the bings aren't even good enough for door stops.
As for the improvements, it was huge. You choke it first thing in the morning and and it starts right up. I could even use the kickstart on it if I wanted too. It was the best improvement I did to it in my 33 years of ownership.
Mon, 09/05/2011 - 00:36
#6
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mmmhhhh !!!!!???
I went to Mikunis on my R75/5 after I rebuilt two sets of bings and as far as I'm concerned, the bings aren't even good enough for door stops.
As for the improvements, it was huge. You choke it first thing in the morning and and it starts right up. I could even use the kickstart on it if I wanted too. It was the best improvement I did to it in my 33 years of ownership.
thanks for your witness,but i've got a question : who rebuilt your bings ?
I've seen a lot of beemers kicking a** using bing carbs. So if in your case they "failed" doesn't mean they are not good carbs.
http://en.wikipedia.org/wiki/BMW_R80G/S
The R80G/S was developed for BMW by engineer Rüdiger Gutsche, a successful competitor in the International Six Days Trial on his specially adapted R75/5[/color].[5] In 1981, Hubert Auriol, riding a R80G/S prepared by German company HPN Motorradtechnik,[6] won the Paris-Dakar Rally.[7] He repeated his success on a 870 cc version of the R80G/S in 1983.[6] Gaston Rahier won the Dakar on a R80G/S in 1984 and then again on a larger 1000 cc engined R80G/S in 1985.[6][8] To commemorate their success, BMW launched the R80G/S Paris-Dakar special edition which featured a 7 imperial gallons (32 l; 8.4 US gal) fuel tank,[8] fitted with dual petcocks and signed by Gaston Rahier.[9]
BMW in the 80's and beginning of 90's ruled the Paris-Dakar and others tough off road races...every bike ran bing carbs.
This is enough to me, to keep on using bing on beemers.
Respectfully
Marco
Mon, 09/05/2011 - 08:29
#7
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I rebuilt them. I have a '72
I rebuilt them. I have a '72 toaster that I bought in 1978 with 11k on it. It always had a flat spot around 2800 RPM. I have since learned that the early /5 bings had problems. So about 4 years ago I bought bings off of a /7. Totally rebuilt them with brand new everything. These weren't any better than the orginals that came with the bike. After all I did and spent on it , I should've bought the mikunis years ago.
It was because of the hard starting, leaking floats and flat spots that I parked the bike for quite a few years. I was then driving an american brand during that time. Ever since I put the mikunis on, I've been riding my toaster alot. She now has 56k on it.
As for bings and quality, my borhter had '70 R75/5 that always started good and ran well. Those were supposed to be the worst year for bings. Go figure.
Tue, 09/06/2011 - 11:26
#8
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hmmm, I guess I will work
hmmm, I guess I will work with the bings for now. My new problem is that gas is spilling out from where the fuel line meets the right carb (whether the right or left petcock is open). I know I must have a clog on the carb side. Replaced the fuel line but it started again once i got on the road. Problem is... I can't get the top of the carb off. Any suggestions?
Tue, 09/06/2011 - 11:26
#9
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I'll clarify, I can't get the
I'll clarify, I can't get the screws at the top of the bing to open for me.
Tue, 09/06/2011 - 12:01
#10
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Penetrant from the underside.
Penetrant from the underside. Are these flat blade screw slots or phillips? They can be a problem if corrosion sets up, hence the penetrant. You need to be careful so as to not break off a flange of the carb top.
The problem is that it's hard to get a good bite and the screwdriver my slip out. Grinding paste can help some with that. The other trick that I've heard about is using a large c-clamp and a bit from a screwdriver with many bits. Configure the c-clamp so that it holds the bit fairly tightely in the screw slot. Then with a small open end wrench, turn the bit. You'll ned to have a third set of hands to loosen the c-clamp. Even if the c-clamp is lightly holding the bit in place, it should afford at least a partial turn of the bit before the excess slack is taken up. You're only trying to break the corrosion loose...after that it should come out easily.
Tue, 09/06/2011 - 12:34
#11
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Thanks Kurt, I tried WD40, no
Thanks Kurt, I tried WD40, no luck, they are flat head screws. Just worried about stripping them. I've been trying to avoid taking the entire carb off but it looks like it might be easier to work with if I do. Once this weeks monsoon stops (hopefully thursday) I will give it another shot. Good luck down there with the wild fires. My Austin area friends aren't fairing too well.
Tue, 09/06/2011 - 13:52
#12
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WD-40 is not a
WD-40 is not a penetrant...it's a "Water Dispersant". Get some PB Blaster or Aerokroil. A 50/50 mixture of acetone and ATF is supposed to be a great penetrant.
Thu, 09/08/2011 - 13:27
#13
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Hey Guys, I finally broke
Hey Guys, I finally broke down and called tom cutter. good news... he is a super nice guy, and lives close to where I live and gave me some quick, concise pointers, many of which you guys had suggested. Bad news, there is an 11 month waiting list! I'm going to flush the hell out of the carbs and replace the fuel lines add in line filters and clean out the tank. he also figured out the problem with my neutral issue. water in the transmission, which makes sense since when I changed it it was soupy and nasty. Hopefully it will stop raining and I can get lucky.
Thanks!
Hey there..
I'm my experience building bikes (pro & hobby) I tend to always go with Mikuni's.. I have put them on Harleys/Hondas/Yammies with no-fault what-so-ever..
They are pretty straight forward to tune & seem to hold up well..
I'm am also going to replace the Bings on my Beemer to Mikuni Flatslides..
Hope it helps..
It's all experimental & in pursuit of an extra tenth..
'75 R75/6 R90 conversion
'74 CB360 cafe