The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: oz_johnno on October 12, 2012, 07:14:25 AM

Title: no spark = no fun
Post by: oz_johnno on October 12, 2012, 07:14:25 AM
Gents,
I was taking my 86 model R65 Beryl out for a run today when about 2km from home the bike suddenly died..... I was like WTF ?

I pulled over and checked the fuel taps.... they were both in the 'on' position

I flipped the clip off the bowl..... both were full of fuel

I disconnected one of the spark plugs, held it near the plug..... no spark seen or heard.

I didnt check the fuse.......

If its not the fuse, is it most likely the coil or the bean can ?  How do I fault find these items ?

also possibly related, I put a new enduralast alternator on last year.  Help please I need to get her back on the road ASAP.

On thursday while I was in rehab, my real estate agent called me to tell me that my wife had backed a truck up to the front door and was removing furniture.......... I came home to a 1/2 empty house.  :'(
Title: Re: no spark = no fun
Post by: Bob_Roller on October 12, 2012, 08:06:39 AM
I would first check the ignition coil, I had the later OEM replacement coil that is red and black  on my '81 R65 .

It quit just like yours did, about a 5 minute walk from home .

I don't know your electrical capabilities, but you need to check the primary and secondary circuits in the coil .

The primary should have around 1.5 ohms and the secondary should have 11-13K ohms .
Title: Re: no spark = no fun
Post by: oz_johnno on October 12, 2012, 08:33:37 AM
electrical capabilities ok as I have an associate diploma in electrical engineering.  Should be able to pull out my el cheapo multimeter and measure the resistance across the primary and secondary ccts of the coil.

I have heard of people using 2x after market car coils wired in parallel.  I think this would look butt ugly and would be prepared to pay the extra to get an oem coil (80 uk pounds at motobins)

Im kind of surprised at the coil's failure as the bike has only 51500km (<40,000 miles) on the clock.

do you think they would laugh if I tried to claim it as a warentee item ?

OZ
Title: Re: no spark = no fun
Post by: Bob_Roller on October 12, 2012, 08:59:42 AM
The original coil on my '81 R65 quit at 24,00 miles (39,000 km), the replacement coil lasted around 25,000 miles (41,000km) .

I've got a DYNA 'brown' coil installed now, a popular aftermarket part here in North America .
Title: Re: no spark = no fun
Post by: Session101 on October 12, 2012, 11:20:47 AM
i would check the signal being sent to the coil first... if you aren't getting a signal then your coils are fine and might be the bean can, or your capacitor
Title: Re: no spark = no fun
Post by: k_enn on October 12, 2012, 04:19:48 PM
Quote
<snip>I disconnected one of the spark plugs, held it near the plug..... no spark seen or heard.
<snip>

I'm not entirely clear what you did here to check the spark.  What did you hold next to what?  The wire near the end of the plug to try to a spark jump from the wire to the plug?  The plug near the hole for the plug?  Either of those two is likely to be "hit or miss."  The best "quick" way I have found to see if you have spark is to remove the plug from the head, connect it to the wire, and lay the plug on the engine (cylinder fins work fine) and turn the starter/engine.  Check the end of plug for any sign of spark.  It doesn't work well in bright sunlight, but you may also hear the spark jumping the gap.  
Title: Re: no spark = no fun
Post by: tvrla on October 12, 2012, 08:32:00 PM
Turn the key on and flip the kill switch. If you get a spark when the kill switch is toggled, but not when the engine is cranking, then it's the bean can/hall sensor.
Title: Re: no spark = no fun
Post by: montmil on October 15, 2012, 07:52:24 AM
Confirm that you have not pinched the wire loom from the ITU "bean can" between the front cover and one of the interior webs. The wire may not be severed but can very well be pinched tightly enough to cause a short to ground.

This happened to me while I was way up in nor'west Texas during a Sunday ride. Easy fix... once getting home and discovering my error.

Always ground the spark plug to the engine when checking for spark. Failure to do so can wreck havoc with the ignition.

Should we offer condolences or congratulations on your acquisition of additional living space?   :-?