The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: crazy_dan on August 23, 2008, 08:47:05 PM

Title: loss of power
Post by: crazy_dan on August 23, 2008, 08:47:05 PM
ok everybody...i'm throwing out a line here hoping to get a couple bites...

i've been having some electrical issues with my '81 lately, it doesn't want to charge...i think i've figured out that problem though, but i'd love some feedback there too, however, here's my dilemma...

i'm riding home from work today, as i ride through town it's stop, go, stop, go, nothing different than usual, i go to leave a stop light, and my bike is severly underpowered, like it's running on one cylinder...i pull off at a park and check to see if i have spark, which i do on both cylinders.  

i limp the bike home and throw it on the charger (because i know that weak spark can be caused by a battery being dead or a charging system that isn't working properly).  once the battery is charged, i start my bike up and ride around the block.  still underpowered, still firing on both cylinders.

have i jumped time?  is there a bigger problem?  is there something simple that i'm missing?  i've been searching my service manual, and everything that it suggests, i've looked into and that's not the problem.

any suggestions would be appreciated.

thanx everybody
d
Title: Re: loss of power
Post by: MrRiden on August 23, 2008, 09:36:30 PM
As the adage states' 90% of electrical problems are fuel related and visa versa. You did state that you had spark on both sides so I'm skeptical about my initial thought of the now famous cracked coil. If you do have the original coil on this bike there is a chance that it is toast. Hopefully someone will post a pic here shortly to illustrate what to look fer. In the mean time...have you pulled the float bowls / diaphragm lately? Lest have a look eh?
rich
Title: Re: loss of power
Post by: Rob Valdez 79 R65 on August 24, 2008, 06:46:57 AM
Sounds like something might be blocking a passageway in a carb, or a diaphragm with a hole or tear in it.
Title: Re: loss of power
Post by: montmil on August 24, 2008, 08:38:47 AM
OK, Rich... I'm on it!  ;)

(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520R65%2FOrigCoil01.jpg&hash=a447270ec5268e3d44ba4a6c971f625f7143d9b3)

Note the tiny circular cracks on the end. That's all it takes.

(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520R65%2FDyna02.jpg&hash=4b03865120f17e4695d05d85b6345b1e6b23bd1a)

Dyna, Dyna, Dyna... Rick Jones at http://www.motoelekt.com/index.html

(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520R65%2FGodsOfBMW.jpg&hash=1340ad7f76f20d56b5f4bc083899b893454207ee)

I need a bigger shelf...
Title: Re: loss of power
Post by: crazy_dan on August 24, 2008, 05:44:33 PM
well, thanx for all the help thus far guys...so i start digging into my carbs, i don't see any tears or anything in the diaphram (not that i would be able to see a  pin hole though), but i noticed that the little round cap in the center of the cap on the carb (bing constant depression carbs) is loose on one side.  that doesn't seem right to me...the other carb seems solid.  any thoughts on this?  

i've gotta tear back into them on wednesday (my next day off) and clean them up real good, i noticed some sediment in one of the bowls.

i checked out my coil, that didn't have any cracks or anything else on it, so i think that's good, side note, monte is that 1.5 ohm dyna coil a 6V?  just wondering because the only dyna coil that i can find that is a 1.5 ohm is a 6V.

once again...thanx guys!
d
Title: Re: loss of power
Post by: MrRiden on August 24, 2008, 06:30:10 PM
Quote
i noticed that the little round cap in the center of the cap on the carb (bing constant depression carbs) is loose on one side.  that doesn't seem right to me...the other carb seems solid.  any thoughts on this?  
Monte's yer man again!  :D  Here's a thread he started:http://suraklyn.com/yabb/YaBB.pl?num=1218388320
rich
Title: Re: loss of power
Post by: Rob Valdez 79 R65 on August 24, 2008, 07:56:44 PM
Quote
Quote
i noticed that the little round cap in the center of the cap on the carb (bing constant depression carbs) is loose on one side.  that doesn't seem right to me...the other carb seems solid.  any thoughts on this?  
Monte's yer man again!  :D  Here's a thread he started:http://suraklyn.com/yabb/YaBB.pl?num=1218388320
rich


I've got to start remembering that little bugger.  Having "flat-top" carbs, it is not an issue for me.
Title: Re: loss of power
Post by: drewboid on August 27, 2008, 12:40:39 PM
You are right on the money with the loose top on the carb causing trouble. BTDT but it took me longer to find the problem. Gel epoxy has worked fine for me. YMMV