The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: saintell on April 14, 2013, 09:28:37 PM
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Hi all,havn't ridden this bike so don't know whether it is an ongoing problem or new one,the bike starts and runs well but will just stop for no apparent reason whether parked or being ridden,the ign lights come back on but will not start straight away and will sometimes flatten the battery,have removed the coil this morning and cannot see any cracks in the coil pack as has been suggested,any help or things to try much appreciated,cheers Nev from OZ :-/
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I had a similiar problem with my '81 R65 about 15 years ago .
The bike would just quit .
I never found the 'smoking gun; that was causing the problem .
I was told by a seasoned airhead owner, to go through the entire electrical system and check all of the electrical connections, found a few that were loose and also found some 'pins' on the connectors that were not locked into the plastic connector body .
Got those taken care of and have not had an issue since, about 60,000 miles .
After learning more about airhead bike electrical systems in the last 15 years, my first suggestion would be to check the fuses, they are a sorry excuse on these bikes and cause more problems than they should .
They are inside of a small black box under the fuel tank area, should have a worm gear clamp securing it to the frame tube .
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I guess the first question is whether the problem is no spark or no gas. Next time it happens, unscrew the gas cap. If you hear a 'Whoosh', and afterwards the bike wants to start, the gas cap isn't venting and you have no fuel (happened to me). If no sound, quick hop off the bike and pop off a float bowl. If there is gas in the float bowl, prob fuel isn't the issue.
Have a spark plug handy. Yank the plug cap and place the new plug in the cap and ground it to the fins on the head. Hit the starter and look for spark. Be careful-you don't want to get shocked and you don't want to spin the starter with the coil unable to get it's spark to ground. Those ignitions are fairly fragile and pulling a plug cap on a running bike will toast the ignition module.
Good luck!
-Armen
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It could also possibly be that the ICU is overheating and needs to have the heatsink paste renewed between it and its alloy heatsink.
Can you tell us what items you have checked or replaced thus far?
Also, if you do have the original dark gray/black coil, I would tend to just replace it as the original factory units from that time period are notorious for failing - the usual method is with small cracks appearing, but those cracks can be VERY TINY and hard to spot. How old are the sprk plug leads, plugs, etc? When your bike does not start, do you still have power to your directional signals (could indicate a loose fuse - the 2 primitive ceramic fuses on the older under the tank are also a common problem source and prompts many of us to replace the fuses with watertight sealed automotive units that use standard auto "blade" fuses).
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It's a genuine PITA but you really should begin your search with a wiring trace and confirm all grounds and connections. A DVOM is most helpful.
Those poor Euro-style fuses can look fine as well as their chezzy clips... but after replacing with newer spade-style fuses in weatherproof rubber holders, all sorts of niggling electrical issues went away.
My R100S had decided not to crank. No reason. Just didn't turn over on the button. Long search found a failed connection inside a nylon connector block up under the fuel tank. Simple fix but consumed the better part of a day.
It's usually something simple, Nev. Finding it is the chore.
And please add your R65's model year in every post -or add it to your sig line capability. Different model years will often require different answers. Your coils are a perfect example as they vary year to year...
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Hi guys and thanks for all your excellent comments and suggestions,the bike is Jan 1984 build date,as I have said I am just getting this bike running after a cosmetic make over,like a film star or maybe a prima donna,the stopping can happen anytime cold,hot,just started or running for 15 minutes,I can borrow a coil so will do that first,as well as contact paste on the other jigger which looks pretty average,still running old type fuses so will replace the holders with waterproof ones,looks like there will be a lot of prep work to do to get this running properly,found it a bit under powered after riding my K100 but I guess I will get used to it,going to use it for a daily ride so needs to be spot on,cheers and thanks again Nev from OZ ::) [smiley=bmw_smiley.gif] [smiley=bmw_smiley.gif][smiley=bmw_smiley.gif]
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Nev,
Go back and re-inspect the ignition coil.
If you still have the infamous gray and black Crack-O-Matic, clean it proper -even removing it from it's mount if necessary- and check for tiny cracks often hidden beneath years of dust. Note the circular cracks I found on my '81.
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520R65%2FOrigCoil01.jpg&hash=a447270ec5268e3d44ba4a6c971f625f7143d9b3) (http://s196.photobucket.com/user/montmil/media/BMW%20R65/OrigCoil01.jpg.html)
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Hi all,I have installed the new coil and fuses also checked the bean can wiring,all good,renewed the heat sink paste and everything is go for the moment,thanks again for all the suggestions and help,cheers Nev