low rpm vibrations

[Air4Life]

thanks Luca.  I should know better than to jump in here...  

Well, I for one am keen I learning what it turns out to be.  I just hope he doesn't give up on this.

[montmil]

Those carb slide tapered steel needles are kinda loose for a reason. They "self-center" as they move into and out of the needle jet. If a steel needle is so tight that it doesn't wiggle at all, it may likely rapidly wear a channel into the brass needle jet and cause mid-range operation concerns.

Did you remove the needles during your carb overhaul? Are the cut-aways on the slides oriented properly?

[thessler]

Wow
This is a lot to digest. My carb job is just a cleaning, I have not installed any new parts.
My thinking and maybe this is short sighted is to get this thing running good and see if I even like this bike before I start dumping more money into it.
Maybe it's time for a rebuild kit for the carbs.
Can anyone suggest a good site to order carb parts from ?

You guys have given me a lot to read and understand so I will need to go back and re read all of theses suggestions and keep trying, maybe ill try that shorting system of sync. The carbs.

Being that I feel there was some improvement today this kind of points to these carbs as the culprit.
Diaphragms are good, chokes installed properly and returning, butterfly's checked.
I know what was suggested to replace the o rings on the shafts, I may be wrong but I can't see a little air leak causing this amount disturbance.
Between 1 and 3 k I can't use my mirrors, can a vacuume leak cause that ?

 Thanks very much for all the help, Tom

[thessler]

Still at it.

I think there is a misunderstanding. I did not overhaul the carbs. I went through them to clean and inspect only.
I removed both needles to varify notch , and freed up the stuck one.
Slides are oriented properly.
Vacuume line is plugged good and the rest of the EPA system is gone.

 Thanks, Tom

[Luca]

Well the EPA removes some of your woes IMO.  (it doesn't seem to bug as many people as it should that it keeps the right carb bowl from coming off)

I think you should rebuild the carbs.  If one needle is new and the other one isn't, it means somebody messed with em' and probably didn't do as thorough a job as they should have.  It's gonna run you a few bucks, but it really sounds like it will be money well spent.  Motobins has rebuild kits, but they'll have to get shipped from the UK.  Not sure who has them in the domestic market, as I got mine from Motobins, but the one important thing is that you use BMW parts... especially the diaphragms.  Some people sell (cheaper) Saab diaphragms as suitable replacements, but many people report problems with those diaphragms as the rubber is not the same in one way or another.

This is a lot to digest.

 yep, I feel for ya.  Carbs can be real a pain in the butt, and even worse when they're an electrical problem.  The trick is to stay cool and methodical, which is why:

I know what was suggested to replace the o rings on the shafts, I may be wrong but I can't see a little air leak causing this amount disturbance.

you don't assume anything.  Put the wrong diaphragm in one carb, have a bad needle or needle jet on another... things can compound.  Don't assume anything.  Eliminate one potential problem at a time.  It's gonna cost you a few bucks here and there, but you will chase your tail trying to sync the carbs to fix your problem if everything else isn't in proper order.  Carb syncing is the absolute last thing you do when tuning an engine.

Best of luck.  We're here for ya'

P.S. did you plug the vacuum ports on the carbs, or plug up the tee in the airbox?  If the hoses are still in place, there could be a leak along the way.

P.S.S.

thanks Luca.  I should know better than to jump in here...  

PSHHHH!  give yourself some credit

[quixotic]

I wonder if I'm in the same boat as thessler.  I bought mine from a dealer about 2 weeks ago (not really a dealer, but a motorad specialist).  It had been on the showroom floor for a few weeks, but when he started it up in the garage prior to me taking it, it sounded quite rough to my untrained ears.  He revved it up to 5 or 6,000 rpm and frowned, saying something wasn't 100%.  Then he took the float bowl covers off and fiddled with the floats a bit.  Then he started it up again.  Maybe it sounded slightly better; maybe not.  But the money was burning a hole in my pocket, so I grinned when he grinned.  

After I got it home (hauled it 100 miles in a pick-up) and rode it, I knew that it was FAR rougher than any other vehicle I'd ever owned.  Even my old 1972 R75/5 was much smoother.  

So, is the R65 significantly rougher than the R75/5?

I soon plan to check the points gap and then the timing, spark plugs, etc.  Then on to the carbs.  

[montmil]

Evan,

We don't want to hijack this thread but, yes, start with the points (perhaps a new set), timing and valve lash adjustment. With 20 thou kilometers, you, too, may be due for a complete carb overhaul.

We now return you to our regularly scheduled programming...

[thessler]

Good news today

I locked the throttle at 2500 and set the carbs. I did not have to adjust much they were close and it did help, not a lot but it helped.

Seems every time I fool with this thing I am gaining a little. Can't say it's right but it is getting better. I will continue to read up and follow your suggestions.

   Thanks, Tom

[georgesgiralt]

Check the return springs on throttle and choke.
I had old springs not strong enough to return the choke off. So the engine had a few choke on all the time (and of course was not the same every ride...)
Buying 4 new one saves fuel