Hi all I have a bit of a dilemma I bought a cafe racer bmw awhile ago (built from scratch im told) and developed a leak around the taps on my petrol tank I decided to look for a replacement for it. On my log book it says its 650cc and when I taxed it online it stated that it was an r65 1981. I located a tank for it and went to collect today and quickly found out that this wasn't the right tank as my old tank has 2 petrol taps and I understand all r65's have just the one? So my question is which engine do I have in my cafe racer? Thanks here's some pics sorry they aren't closer ones I pulled these off the hardrive but can take more tomorrow. https://picasaweb.google.com/107204...hkey=Gv1sRgCPjVkrCr1-iGCQ#5614145529158413538 https://picasaweb.google.com/107204...hkey=Gv1sRgCPjVkrCr1-iGCQ#5614490737803258658
LLOk at the cylinder base where it joins the engine it will have the displacment cast into the cylinder wall ie 80 100 etc also the engine number will give you a good idea and look it up on one of the engine number guides. Your bike may well be an r65 or r80 but the tank looks like an r80 tank. I would think all the fuel cocks are the same anyway. I do like the exhaust cans do they have a name on them and do they run well. ?
That looks like a standard 65/80/100 tank. If you bought one with a single tap It will be the thinner flat sided one. If you want to flog it send me a PM. I'm in the East midlands. I take it you're in the UK? Looks like Yorkshire? Get in touch with Jake at South coast Boxers http://stores.ebay.co.uk/southcoastboxers he's on holiday at the minute
I looked and the engine and frame numbers and they match and couldnt find them on a site that listed engine numbers is it possible it is an r65 and that it has been modified to use 2 taps? Im not sure what to look for on the cylinders but underneath them it has 2 bars going into the cylinder if that helps. Not selling just yet as I havent had a chance to ride it much at all I'm in barnsley thanks for the ebay site I'll take a look. The cans sound great but cant find a brand name the odd pop on de acceleration but Im told that's normal on short cans.
Why replace the tank to fix the leaks? There's a hard red fiber washer at the junction that possibly needs to be replaced. Or just tighten it a little if it's loose. The tank is right-hand threads, the petcock is left hand. When the nut is turned the normal direction to tighten, it will draw the two (tank, petcock) together. Don't over-tighten as the petcock being aluminum will strip. I can't tell what engine it is from the photos, but the bike (or the bits) appear to be of 81-4 vintage. The gas tank looks to be the normal tank of that era - not R65, R80G/S or ST. At the base of the cylinders will be a number designating what size it is. If it's an R65 it'll be 6.5, 800cc = 8, etc.
Unfortunately it is thinned around the taps and 2 pinholes are about half an inch and an inch away from the taps its been with a repair guy for 2 weeks now he says he will try and use the sealing solution in it and that its possible it wont work bmw motorworks are looking for a tank for mine now its a costly 240 pounds for a replacement I Had no luck finding one on ebay.
The exhausts and seat unit, rear sets etc look like www.flatracer.com Airheads are just big meccano kits with most parts being interchangeable. Here's a picture of my engine. At the rear of the barrel, near where it joins the engine block you can see a 10 - this means it's a 1000cc. Your barrel will have a number stamped on it somewhere - 65 if it's a 650
Your tank is one of these http://www.ebay.co.uk/itm/motorcycl...cycle_Parts&hash=item4aad1e1ab5#ht_500wt_1156 just do a search on R80 or R100 and look for the tanks, don't worry about the bikes they come from they are mostly interchangeable
Hi thanks for the replies I saw the 6'5 on the cylinder head so it is indeed an R65 someone must have added another fuel line to fit the new tank does anyone know if it is done to increase performance? maybe its just for cosmetic reasons because the tank looks better? It looks like my old tank will be repairable should know for certain in the next few days thanks for the ebay link Im still watching it as I could do with a spare.
Mufflers look like Emgo reverse cone shortys. Cheap as chips but decent. http://www.nichecycle.com/ProductDesc.aspx?code=80-84030&type=0
The lobes on the older tanks sit lower so when the fuel level drops you end up with fuel in each lobe. The two fuel taps allow access to each of them. I run my 1000cc bike on one tap most of the time, it's never been a problem even at high speed. I'm glad your tanks looks like it can be repaired. Rotting tanks are becoming a frequent problem. I've got two hanging on my wall. It's not a bad idea to drain the tank once a year to get any water out. Both of mine have pinholes near the fuel taps, probably caused by water sitting at the bottom of the tanks. The ethanol in modern fuel finds any weaknesses. Sureseal tank sealer works really well but your tank will be out of use for a month while it fully cures. Loads of info on tank sealing/cleaning here http://www.tankcareproducts.co.uk/
It's a R65. You can tell by just looking. R65 tanks are a different shape, have a different mounting system, and have one petcock. They are also a different length so the seat fits differently against the tank. R56's have a lot of stuff that won't swap bolt for bolt with the other bikes. Forks, swingarm, shocks, sub frame, exhaust, seat, tank, front wheel, final drive, most of the engine. The wiring harness is more like a GS than the other bikes until '85 when they all got the R65 style wiring setup.
