Reason for stumbling idle found!

[Allred]

I've ridden my new-to-me '83 R65 about 600 miles over past six weeks, as it gets better and better as I address some of the maintenance and repair issues it had when purchased.  All the while there has been carb issues.  I got them reasonably well adjusted and synched, but still the idle was lumpy at best, and sometimes varying from 800 to 1200 rpm, without much reason or discernable cause.  

I knew a carb over-haul was likely needed.  Got a complete kit from Bing Agency, and yesterday dug in.  The floats were set a bit to high, and the float needles just beginning to show some wear.  Replace 'em both, and also installed new needle jets and needles along with piston diaphrams.  

"Whoa, what's this?  One carb has one less piece in the jet stock colum than the other!!!"

The left carb was missing the atomizer, that correctly surrounds, and positions the needle jet, when held in place by the main jet-stock column.  See photo at link below, the jet column parts on the left are for the left carb, four pieces.  The same colum on the right are from the right carb, five pieces.

http://www.allreds.net/~robert/missing%20atomizer%20on%20left.JPG

There is only one atomizer, the part in the center of the two jet stock columns.  There should be two.

I'm pretty confident this, along with correct float setting, new float needles, new floats and shafts, new needles and needle jets, and piston diaphrams, along with complete cleaning & flushing of all cavaties & passage ways (jet stock column area was pretty grungy) will solve the irratic idle tendencies.  Thats the good news.  

The bad news is that I won't know for sure until once again I wait for Bing Agency to open Tuesday morning, and place an order for the missing atomizer, and then wait another week for it to arrive.  

I'll keep you posted.

[Semper Gumby]

Hi Allred

Two other sources of "erratic idle" is an unwanted air source like a rotten rubbler pipe between the carb and the cylinder head or the throttle shaft get loose when the o-rings on the shaft dry out where the shaft goes through the throttle body wall.

Good luck.

[Allred]

As I thought, erratic idle all curred now, after thorough cleaning of all carb fuel jets & air passages, and fitting of new "0" rings, needle jets & needles, floats and floar needles my R65 no longer dies at idle.  Indeed it will now idle steadily at reduced rpm's compared to before.  Of course replacing the missing atomizer in the left carb helped too.

Now, after re-setting the idle mixture screws, adjusting the idle speed screws, and syncing the cables, all is well.  "Chiquita" will purr away at a steady 800 rpm for as long as I care to allow.  

I'm a happy camper!

[Justin B.]

I love it when a plan comes together...  Funny it would even run good enough to ride with bits missing from one of the carbs!  You never know what kind of thought processes (or chemicals) cause POs to do some of the crap they do!