The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: NorR65 on March 14, 2010, 04:51:43 AM

Title: R65 1981 - bad coil?
Post by: NorR65 on March 14, 2010, 04:51:43 AM
I found the OT markings at the flywheel, valves was already OK after my first attempt. I have changed the sparkplugs, airfilter and fuel filter.
I had a 20 min ride and it was OK until my engine got some "hick-ups".
It feels like engine stalls a fraction of a second. It got worse when engine got hotter. It was damp weather and the coil is the old one, probably from 1981. I guess I need a new coil?
Title: Re: R65 1981 - bad coil?
Post by: Bob_Roller on March 14, 2010, 07:56:43 AM
If it's gray and black in color, it would be advisable to replace it .

This particular coil has earned the reputation for being the 'crack-o-matic' coil, due to it's fondness for having the plastic case develop cracks, and causing problems in damp or wet conditions .

BMW has a replacement OEM coil, it's red and black in color, but fairly costly .

Don't know what's available to you in your region, but the Dyna 'brown' coil is a popular replacement here in North America .

I do recall, I believe a member here had mentioned it, that some of the dual output coils from K series BMW bikes ( I believe it's the K100 bikes) work quite satisfactory, but I think you need to make an adapter bracket for it to fit the R65 .
Title: Re: R65 1981 - bad coil?
Post by: montmil on March 14, 2010, 08:56:37 AM
The Crack-O-Matic OEM coil can drive you nuts; particularly on damp days. The above mentioned cracks are usually microscopic in size and hidden by under tank dust n' dirt. A cleaning and close inspection will usually turn up a fault or two.

(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520R65%2FOrigCoil01.jpg&hash=a447270ec5268e3d44ba4a6c971f625f7143d9b3)
Note the circular pattern on the end of the coil. Not good.

(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520R65%2FDyna01.jpg&hash=39bb5a2ec402f1260e47ddc3d16414829f2a73cf)
The Dyna Brown -actually kinda orangey- bolts right up with the supplied bracket, hardware and instructions. Mine came from Motorrad Elektric http://www.motoelekt.com/index.html

The odd and inappropriate wiring bits pictured were part of a PO's fairing install. They're long gone.

Monte

Title: Re: R65 1981 - bad coil?
Post by: Barry on March 14, 2010, 11:47:51 AM
In addition to the coil being faulty It's also possible that the electronic ignition module under the tank is overheating which will require the old  thermal paste to be cleaned off and renewed. Its an easy low cost job and any type of thermal paste designed for use with electronic or computer heat sinks will do.
Title: Re: R65 1981 - bad coil?
Post by: Bob_Roller on March 14, 2010, 11:50:47 AM
If you still have the spark plug wires with the metal caps at the plugs, time to replace those as well .
Title: Re: R65 1981 - bad coil?
Post by: montmil on March 15, 2010, 09:01:46 AM
And that new coil just begs for fresh plug wires, too... Also, don't forget a light smear of dielectric grease on the coil wire terminals.   Monte
Title: Re: R65 1981 - bad coil?
Post by: NorR65 on March 15, 2010, 02:04:55 PM
Thanks for your help.
My coil has a lot off small cracks. Since we usually has a lot of rain were I live, a new coil and thermal paste for the ignition module is the way to go.
The spark plug wires are not the metal ones. I think I have to order a coils from Motobins or Motorworks in UK. I am afraid it will cost to much to send a Dyna coil from USA to Norway.
Title: Re: R65 1981 - bad coil?
Post by: Bob_Roller on March 15, 2010, 02:09:37 PM
The owner of Motorrad Elektrik, Rick Jones, ships parts worldwide .

Send him an email, and see what the costs are for shipping, then make your decision if it's cost efficient or not .
Title: Re: R65 1981 - bad coil?
Post by: ukzknos on March 16, 2010, 03:41:42 PM
NorR65

These coils are also available from the UK, a little closer!

I recently received my 3 Ohm DC1-1 (for the 79/80 points version) from here:

http://www.dynatekuk.com/sport_bikes_ignition_coils.html

It was c.£72 delivered.
A good long term investment is my view! :)

Steve
Title: Re: R65 1981 - bad coil?
Post by: NorR65 on March 17, 2010, 03:40:44 PM
Thanks
The price from Dynatek UK is £120,77 for the brown coil + delivery.
From USA it is $ 90 + $45 for sending it to Norway.
I have to decide what or where to order. I need a new coil.
Title: Re: R65 1981 - bad coil?
Post by: ukzknos on March 17, 2010, 03:51:08 PM
Quote
The price from Dynatek UK is £120,77 for the brown coil + delivery.

Hi NorR65

You are slightly mistaken as the £120,77 is for 2pc dual output coils, ie for 4 cylinder bikes.

You only need 1pc dual output coil which is £60ish pounds + shipping!

Regards
Title: Re: R65 1981 - bad coil?
Post by: NorR65 on March 19, 2010, 02:54:47 AM
 I have ordered a coil from Motobins yesterday.
Dynatek would only send the coil a needed in pairs.
And they would not send outside UK.
Thanks again  for your advice.