I want to replace the jet needle (nozzle needle in the fiche) but I can't figure out how to remove them. My manual says something about push and twist, but I can't figure it out. The fiche shows clips and toothed rings, but as I understand it, not all models use those clips? Also, once I get them out, it must be challenging to get them back in at the right groove? Any advice? Thanks
Twist the needle 90 degrees or 1/4 turn and gently push up on the needle. Continue the 90 degree rotation until the needle comes out. Count the number of turn to determine what groove it was in. You can also measure how far the needles stick out to get the same location when they are replaced. It becomes pretty obvious how that works when you actually see the needle. Chuck
+1 it helps to wear latex gloves or similar for a slip-free grip between fingers while turning the needle through 90 degrees, at which point it can be drawn to the next pair of opposed notches, or out as the case may be.
You probably have to have Latex or some type of glove to get a grip on the smooth needle. I didn't have any nice clean new latex gloves the last time I did this and ended up with an old pair of gardening gloves in heavy rubber. Well it worked. Your leather motorcycle gloves probably won't work. The needle is slippery.
http://youtu.be/vFnTVxm0FVw <iframe src="http://www.youtube.com/embed/vFnTVxm0FVw" allowfullscreen="" frameborder="0" height="315" width="420"></iframe> <embed <embed </embed <embed </embed
What are the markings on them? There should be an X or some other markings to denote which needle is which.
Now that I think about it...I may have imagined doing that on my bings. I think I did that for my Amals haha. Sorry, way too many carbs in my life at the moment.
I've used lightweight Vice Grips, set real low on the squeeze scale, with rubber strips on the teeth. The job got done, but I almost had heart trouble while doing it. Latex gloves seems like a good idea.
I just ordered all new needles, jets, and whatnot from Max. Are you telling me they are the wrong part now? So what's the correct part number?
I have 32s on my 91GSPD, and the fiche says PN 13 11 1 337 692 :huh I guess I'll see what happens when I get them apart. Oh, sorry, I'm probably just confusing things, didn't realize you guys are talking about 70's bikes which probably had different bings. Nevermind me.
I have checked realOEM dot com for your part numbers. The carbs on an R100/7 for 1977 are 64/32/19 & 20 The carbs on an R100RS for 1977 are 64/40/103 & 104 Both the 32mm and the 40mm carbs list 13 11 1 335 321 as the jet needle. The #840 appears to be a much later GS or G/S needle, not sure. I seriously doubt that both Max BMW and Bob's BMW have made this mistake. If there was a mistake in the current fisch it wouldn't match the parts they have on the shelves and it would be rather impossible for this to be a long standing problem. I would use the new needles from Max. Those shorter needles that you are taking out are probably something an airplane mechanic or somebody used. (did you know many of these carbs are used on airplanes?)
I had to edit my earlier post. I had listed the RS carb as a 32. I've changed it to 40. To begin with stop trying to figure our what all the possibilities are. Just get the needles you need. I think you already have them. The 321 needles.
So you say that Max and Bob's both said the 321 needle at first but now Rusty is saying that he agrees with Motobins and you want the 840 needle? I've heard good things about Rusty but that doesn't make him right. You could get both and see what works best? I don't think the needle has to be longer in a 40mm carb. I still think the 321 needle is right. But I could be wrong. From the picture you showed the longer needle looked like what I have in my carbs. (my R90/6 is the same vintage as your R100/7).
Rusty and Motobins are right. I have run into this before. 40mm carbs do have longer needles. It makes sense to me. Why replace those needles to start with? They look fine in the photos. That type lasts WAY longer than the later type because of the different way they are mounted. The earlier mount setup doesn't let them vibrate and wear like the later setup does. If you can't feel a ridge with your finger nail on the straight part of the needle, they are fine.
So. Now everybody with the older style 32mm carbs has the wrong jet needle in them? edit; If SS agrees with Rusty then I have to say the evidence is over whelming. I'll get new needles this week. I wonder how many thousands of bikes have the wrong needles in them?
Sooty left plug? Do you use the side stand? Seventies BMW's are mostly jetted rich on the mains. 35mpg? Sounds about right to me unless you ride REAL slow. Needle wear? It all depends on what carbs you have. I noticed needle and jet wear in SOME Bings decades ago and always warn about it but all that is mostly about later carbs, not ones like you have. The internet crowd has jumped on the band wagon but has yet to catch on that not all Bings are created equal as far as this issue is concerned. IMO the why and how of it all is readily apparent when you compare the two different needle mounting systems.
I did some further checking. Your suspicion that the problem seems to be with bikes that had a 40mm carb in some models seems to be correct. All sites list the correct needle for my R90/6 with 32mm carbs. But the R100/7 with 32mm carbs has the needle for 40mm carbs listed on all sites except Motobins.
You can also drill your 142s to whatever you want. Class act is to ream them but if you are careful drilling is fine. You can also solder up the jets and drill them smaller. But they're pretty cheap (most of them). I somehow recall the needles being steel. But The ones I have around are SKA and ain't no iron in it. if indeed the older type were steel it would explain why I never saw a worn needle. 35mpg (for US gallons and miles) sucks. I can beat that running at a steady 90-100 mph at sea level with a worn engine. Sumthin' don't quite sound right.
BMW finally jetted their small port 1000cc engines, which is what you have, with 135 mains and that about nails it but 135 mains about nails it in a R65 too. Go figure? People say over and over again that BMW jetted those mains for the EPA. No. They jetted them for power. Finally! They jetted the needle jets for the EPA. I suspect those 40mm needles work in 32mm carbs for those models being so rich on the mains from the factory. The too long needles probably gets them jetted about right on top? I was just thinking that the square airbox horns might have something to so with those 135 mains on the later small ports for increasing port velocity. Well. there is only one way to find out. That is if the 142's aren't too lean to start with! :) How do you tell? If it pings or simply just won't run up on the mains.