R50 Idle

Darryl.Richman · Post by **Darryl.Richman** » Wed Apr 29, 2009 10:59 am

Sounds like your centrifugal advance weights need to be cleaned and lubed.

taben6976 · Post by **taben6976** » Wed Apr 29, 2009 12:01 pm

Darryl, thank you very much for the prompt reply. If you don't mind, let me also note that after this happened I got some smoke from the exhaust on the restart. It was a one time thing. After restarting when it cooled down it was fine - and I'm commuting on the bike today there were no issues. The smoke may have been unrelated, but somehow I suspect shuting it down at 3,000 rpm was a factor. Again, many thanks. There is a fabulous mechanic at Cliffs here in CT, and any guidance I can give him when it's next serviced will be very useful. I love these machines...but have limited technical skills or knowledge.

Charlie

Darryl.Richman · Post by **Darryl.Richman** » Wed Apr 29, 2009 12:13 pm

Did you park your bike on the sidestand before the smoking restart? It's possible, when the stars (and your piston rings) align right, for the left cylinder to pull in a bit of oil when parked on the sidestand. A little oil will make an amazing quantity of smoke.

If you encounter the high idle, you can try the following diagnostic to see if it may be the advance weights: hold the brakes while gradually letting the clutch engage in first gear. As the clutch makes contact, the idle will slow down as the bike tries to drive against the brakes. When the engine slows to what seems like a normal idle speed, pull the clutch in again. If the idle stays low, you likely need the weights cleaned and perhaps new springs. If not, you probably have a carb issue.

taben6976 · Post by **taben6976** » Wed Apr 29, 2009 12:30 pm

Thanks on both fronts. In fact, I do think I put the bike on the side stand before restarting. I did start it again when I returned home on the side stand...but I probably had burned all the oil by then. I rarely use the side stand...so I think you have diagnosed the problem. On my commute in today I kept looking for smoke in the mirror. Talk about irony, I considered riding my '70 Triumph (T100C) to work today, weighing whether it might be more reliable I made the right call and took the /5

Good idea on the second test. Coincidentally, I just did some carb work. I bought the bike restored, but had some starting issues, particularly in the cold. A local guy replaced a few parts, but it's still a little hard to start. There is no choke and the carbs have these accelerators (?) that spray gas, and I still trying to find the right routine on a cold start. It could very well be that my carbs still aren't quite right...but I bet you are correct. I will run your test on my way home after warming up the bike

Again, thanks for all the help. Soon I will figure out how to get my pictures on the web, so I can share photos. The /5 is a very novel, in a non-original black/red. I would be curious to get people thoughts. My /2 is also a non original color...an alpine white. Both were beautifully restored by Perry, formerly of the Fort Worth BMW shop. I have some nice accessories on the /2. I will figure out how to post pics soon. Thank you again for all your prompt assistance

schrader7032 · Post by **schrader7032** » Wed Apr 29, 2009 8:53 pm

Charlie -

In addition to the advance weights, Darryl mentioned a "carb" issue. My thought is that you didn't thoroughly warm up the bike before performing the carb synching. After doing extensive carb overhaul or changing parts, etc., it's necessary to go through the balance process to return carb opertion to normal. If you don't warm the bike up, say 15-20 minute ride, then you would be setting the mixture and cable tension with the "cold" fuel/air coming into the carbs. Things change when the carbs are warmed up to operating temp.

Perform the test on the advance weights...maybe that's it. After that, I'm guessing you need to rebalance your carbs.

Kurt in S.A.

taben6976 · Post by **taben6976** » Wed Apr 29, 2009 10:02 pm

Thanks Kurt. That is a distinct possibility. It was cooler today and the bike never got warm enough where the idle started to race. It was in the mid 80's the other day, when the problem was pronounced

taben6976 · Post by **taben6976** » Wed Apr 29, 2009 10:18 pm

Trying to add some pictures...hopefully this works

http://s729.photobucket.com/albums/ww292/ctaben/

Darryl.Richman · Post by **Darryl.Richman** » Wed Apr 29, 2009 10:50 pm

Now that you have your photos up on Photobucket, you can copy the "direct link" and put it between

tags, and the actual picture will appear in your posting:--

(BTW, beautiful bikes you have!)

VBMWMO · Post by **VBMWMO** » Mon Feb 15, 2010 2:52 pm

Quick question about my '70 R50/5. I've noted that after it runs for awhile the idle picks up considerably - sometimes remaining at 2,500+ rpm. Sometimes it stays there and drops to normal, but other times it doesn't seem to drop. I've also noted this phenomenon with my '68 R60/2. Is this normal? My /2 was tuned by a great guy in CT, so I suspect it is normal. The R50 is new to my stable, and a little more pronounced, so I figured it was worth a post to this knowledgeable crowd. For the sake of completeness I will note that the R50 was bored for 600cc pistons and rings and the restorer recut the swishband at the top of the piston to bring compression ratio down. Thx in advance for any observations

Charlie