The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Adamastor on September 29, 2009, 05:30:23 AM

Title: No spark
Post by: Adamastor on September 29, 2009, 05:30:23 AM
Hi there!

For the first time in my life I had to call for help because my bike left me stranded on the road.
I was ridding well at about 100km/h and suddenly teh engine got dead... starter works fine, I get gas, there's compression but no spark on both cylinders.

I still have the bosch crack-o-matic coil (with cracks), is this it? Does it get dead with no further notice? Is there an easy test to know if it is the coil or the sensor the culprit?


Regards,

Sergio
Title: Re: No spark
Post by: Bob_Roller on September 29, 2009, 06:38:35 AM
When my crack-o-matic failed, I was at a stop light, and the bike just quit, no warning .

I you have a multi-meter, check the primary and secondary circuits of the coil for continuity .

If the coil is good, the primary circuit should have around 1.5 ohms, the secondary circuit should have 11-13 k ohms .
Title: Re: No spark
Post by: Adamastor on September 29, 2009, 08:16:41 AM
I'll check it tommorow, thanks :)
Title: Re: No spark
Post by: montmil on September 30, 2009, 05:03:04 AM
Replace the coil, if it's bad, with a Dyna from Rick Jones at Motorrad Elektrik. Ride happy.     Monte
Title: Re: No spark
Post by: Adamastor on September 30, 2009, 02:47:25 PM
Quote

If the coil is good, the primary circuit should have around 1.5 ohms, the secondary circuit should have 11-13 k ohms .

Hi!

I had the chance to measure it tonight... the primary circuit has 1.8 ohm and the secondary has 8.8 k ohms... Is this coil ok?

Regards,

Sergio
Title: Re: No spark
Post by: montmil on September 30, 2009, 06:19:48 PM
Quote
Quote

If the coil is good, the primary circuit should have around 1.5 ohms, the secondary circuit should have 11-13 k ohms .

Hi!

I had the chance to measure it tonight... the primary circuit has 1.8 ohm and the secondary has 8.8 k ohms... Is this coil ok?

Regards,

Sergio

Secondary reading looks "iffy". If the coil shows cracking, then it's a goner. It will fail on you at the worst possible moment. Time for a replacement.   Monte
Title: Re: No spark
Post by: Adamastor on October 01, 2009, 04:11:06 AM
Yesterday I done another test, the Ignition Module test where you put a pin on the middle conection of the 3 pin conection, and earth it to see if you get any spark at the plug.
No spark.

I guess this test is useless if the coil is bad, because I wont never see a spark if the coil is defective.

Since the coil is cracked, and I dont want to be left on the road again, I ll order a new coil.
Big question: what is best? Dyna coil from Motoelektric or Bosch coil from Motobins? Price should be very similar, but Dyna coil will take much more time to arrive to my house (across the ocean and the awfull portuguese customs).
If they are similar I would buy the bosch because It arrives faster...
note: I have the electronic ignition 1985 R65 (no points)

If my Ignition Module is also bad is this a cheap part? (I read somewhere it was used on several cars)

I like my R65 so I really want it to be running well... :)

Regards,

Sergio
Title: Re: No spark
Post by: montmil on October 01, 2009, 05:34:39 AM
The Ignition Control Module (ICU) very rarely fails. The ICU in the R65 is also used in a variety of VW and Audi autos. I have a list somewhere... It is not expensive. $30-45 USD.

Best care for the ICU is to refurbish the heat sink paste between the ICU itself and its aluminum heat sink body. Electronic stores sell small tubes of the stuff.

I would counsel against the Bosch replacement, unless you really need to ride the bike right now. If you could afford the time, order the Dyna. You will not regret the wait. The Bosch may last or...

Monte
Title: Re: No spark
Post by: Adamastor on October 01, 2009, 06:09:38 AM
Hmmm ok, I rather not ride the BMW for a month and have a reliable bike after that, than the opposite..
Meanwhile I will try to do other kind of jobs (clean/lube the splines, change one front rotor (warped) and brake lines, change one rocker arm adjuster bolt, etc). Lots of work to be done...

Regards and thanks once again for the opinion

Sergio
Title: Re: No spark
Post by: Adamastor on October 01, 2009, 06:58:02 AM
After posting the above message I went to the garage in order to do some more things on the bike. I remembered to put new heat sink paste on the ICU. When removing the ICU (it was kind of glued to the heat sink) the black plastic part was ungluing from the metal part.. I stopped pushing from the plastic part and managed to remove the whole ICU without separating the plastic from the rest.
New heat sink paste on it and refastened it in place.

Just for the kicks I decided to crank the engine and see if any spark showed up... IT DID! o_O

Is my coil good after all? If the ICU is a bit messed up, when I pushed it could anything wrong gone good?
I think I must buy a new one now because there are no serviceable parts inside, right?

Maybe I didnt need a new coil, but it will be a good investment anyway, since it would develop a problem sooner or later...

Now I need to search for the cars that used an equal ICU so I try to find locally a new one...

Regards,

Sergio
Title: Re: No spark
Post by: Bob_Roller on October 01, 2009, 08:00:33 AM
The ICU was used on a large number of european 4 wheelers of the same era,  I know VW and BMW used them .
Title: Re: No spark
Post by: Danie on October 01, 2009, 11:26:28 AM
My R65's coil has been replaced at least four years ago with a used Honda CD 200 coil - bought for about $3.00 USD at a local bike shop which sells second hand spareparts. It works perfectly.

Danie
Title: Re: No spark
Post by: drewboid on October 01, 2009, 11:41:25 AM
If the coil is cracked BUY A NEW ONE!!!
Many will fit - even the Honda goldwing coil #30500-422-003 is usable.
You need to look for a coil with a primary resistance about 1.2 ohms.

The cracked coil may work today but when the humidity rises, it rains, or it deteriorates more it WILL eventually let you down.
Title: Re: No spark
Post by: Adamastor on October 01, 2009, 12:31:41 PM
Oh well, I already ordered the dyna coil... (a bit expensive with postage) Maybe I should have searched a bit before...

I just bought the ICU from a local auto parts shop very cheap....

Should I connect the new ICU to the old coil while it doesnt arrive, or maybe should I wait?

Regards,

Sergio

ps: I must take some photos of the electric part of my bike, because there are some things I dont know their purpose...
Title: Re: No spark
Post by: the_admiral on October 01, 2009, 04:00:29 PM
hi there are three electrical conectors under the tank make sure these are nice and clean,espeicially the white one,this caused a no spark for me
Title: Re: No spark
Post by: montmil on October 01, 2009, 06:21:56 PM
Ad-man, you made a good choice in the Dyna coil. It will fit on the original coil's location bracket and look very OEM "factory".

Even if the coil sparked up today in a nice, dry environment, it will go tits up on you on a humid day. It's not known as the Crack-O-Matic for nuttin'.  :D

Now appears to be a good opportunity to take care of your maintenance and rehabilitation projects. I had my '81 R65, "Blackie", down for nearly four months after I bought it... tires, coil, fork overhaul, blah blah blah.

Have fun with it. You'll learn a lot and become the Portugal expert. [smiley=thumbsup.gif]

Monte