The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Bob_Roller on May 27, 2007, 12:17:41 PM

Title: Sparkplug Gap
Post by: Bob_Roller on May 27, 2007, 12:17:41 PM

What is the recommended spark-plug gap for an electronic ignition equipped bike ? I have an owners manual that came with the bike, but my bike was the 9th bike off of the production line for the '81 model year, and I have an owners manual for what appears to be the '80 model year bike, only shows a points type ignition system.

Title: Re: Sparkplug Gap
Post by: MrRiden on May 27, 2007, 01:55:08 PM

Points / electronic I think wouldn't matter as that is the trigger part of the ign. I think what would matter is standard / hi output coils (blue Bosch ect.). From Boxerworks: ".024 inch with stock-coils and .030 with the blue coils or any other higher energy coil. Then there are the manufacturer charts Gap for a BP7ES is .028". per the NGK applications guide. Ah but then there is the BMW guide which says 0.024-0.028. then of course there are the rare metals plugs which are different, not to mention multi electrode and aviation style gap less plugs. Woa! Simple question with a confusing array of possibilities. I have the electronic and use NGK or Autolite plugs with the NGK resistor caps and just set them to 0.025. Werks for me, ymmv.
rich

Title: Re: Sparkplug Gap
Post by: Bob_Roller on May 27, 2007, 02:18:05 PM

Thanks for making the subject more confusing Rich! I was setting my plugs to .028, seemed to work OK. Now for today's consumer tip, don't waste your money on exotic spark-plugs. I ran Bosch platinum plugs in my R65, and with the wasted spark ignition system that's used on our bikes, the plugs would be wore out in 5,000 miles. I went back to standard non-resistor Bosch plugs for 59 cents each, and can't tell any difference with how the engine runs, or any difference in fuel consumption.

Title: Re: Sparkplug Gap
Post by: MrRiden on May 27, 2007, 02:51:59 PM

Agreed! I've been known to use AutoLite #64 plugs at a similar price with like results. I sort of think that as long as you use the resistor caps your covered and plug selection (other than heat range)  is not so critical in our low compression machines. Now an 11.1 Brit bike (also wasted spark technology) can be real fussy.
rich

Title: Re: Sparkplug Gap
Post by: Justin B. on May 27, 2007, 09:49:00 PM

I have always used .024 in all of our Beemers, they seem to be sensitive once the gap grows.  I think I have read somewhere .024 - .028 so the .024 allows for wear, at least thats the way I rationalize it...

Title: Re: Sparkplug Gap
Post by: Ed Miller on May 28, 2007, 12:42:02 AM

Bob, where are you finding plugs for fifty nine cents each?  My local Napa only comes up with a resistor plug for my bike, so I buy them from the dealer.  Bend over, Ed!  

Title: Re: Sparkplug Gap
Post by: thrang on May 28, 2007, 04:10:20 AM

I set mine at .025 and use Bosch Superplus, or occasionally NGK (if I cannot get Bosch's at the time).

Title: Re: Sparkplug Gap
Post by: Justin B. on May 28, 2007, 10:07:09 AM

I am having trouble finding the non-resistor plugs but still have some left from the box I bought a couple years ago and I think they worked out to be about $1.25/ea from FCP Groton online.  When did you pay 59 cents for a plug, when you layed in stock 10 years ago?  ;)

Title: Re: Sparkplug Gap
Post by: Bob_Roller on May 28, 2007, 10:12:56 AM

I bought the plugs from NAPA ( No Auto Parts Available) about a year ago, I just looked at the receipt yesterday $1.18 plus sales tax for two plugs.

Title: Re: Sparkplug Gap
Post by: Justin B. on May 28, 2007, 11:20:54 AM

Damn, that's cheap...

Title: Re: Sparkplug Gap
Post by: Ed Miller on May 29, 2007, 12:27:16 AM

Are you sure there's no "R" in that part number?  If not, what is the number they order them by?