The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: leswaller on March 07, 2012, 04:38:34 AM

Title: Starting an early bike with slider carbs
Post by: leswaller on March 07, 2012, 04:38:34 AM
I have seen lots of info on the cold starting technique for bikes with Bing diaphram carbs and chokes.
However can anyone tell me the recognised technique for cold starting a bike with the earlier slider carbs and no chokes.
Thanks in anticipation
Les
Title: Re: Starting an early bike with slider carbs
Post by: Barry on March 07, 2012, 01:06:56 PM
I haven't had a BMW with slide type carbs but I thought they had "ticklers" to flood the carb. In which case after flooding I would crack the throttle just a touch and then start away.

Title: Re: Starting an early bike with slider carbs
Post by: montmil on March 07, 2012, 01:38:26 PM
Quote
I haven't had a BMW with slide type carbs but I thought they had "ticklers" to flood the carb. In which case after flooding I would crack the throttle just a touch and then start away.

Much like the Amal metered leaks on my old T100C. The gasoline always left me with a certain scent.
Title: Re: Starting an early bike with slider carbs
Post by: Barry on March 07, 2012, 02:01:52 PM
Quote
The gasoline always left me with a certain scent.


...certainly did with me too and a stain around the tickler button.  I think the Bings might be a touch more civilised than Amals in having a separate overflow outlet.
Title: Re: Starting an early bike with slider carbs
Post by: Lucky_Lou on March 07, 2012, 02:57:54 PM
Quote
The gasoline always left me with a certain scent.
Napalm in the morning ??
In cold weather i used to start my C15 with my hand over the air intake (Funnel type).... back in the land that time forgot.Obviously no good on a twin.
Lou
Title: Re: Starting an early bike with slider carbs
Post by: montmil on March 07, 2012, 03:33:28 PM
Quote
...and a stain around the tickler button.

 
[smiley=ROTFLMAO.gif] Barry, only a true-blue motorcyclist would understand this without having impure thoughts.

I salute you, sir. [smiley=thumbsup.gif]
Title: Re: Starting an early bike with slider carbs
Post by: leswaller on March 08, 2012, 06:45:35 AM
I tickle the carbs religiously, no stains - separate overflow - just wet patches on the floor  :o
but in spite of this the engine takes 5 or 6 goes on the electric start before catching. Once it is warm I dont have a problem
Les
Title: Re: Starting an early bike with slider carbs
Post by: montmil on March 08, 2012, 09:10:54 AM
Les, Do you mean 5-6 revolutions of the engine before firing or 5-6 attempts on the button?

And what year and model Airhead are we discussing?
Title: Re: Starting an early bike with slider carbs
Post by: Barry on March 08, 2012, 09:32:29 AM
Quote
tickle the carbs religiously, no stains - separate overflow - just wet patches on the floor  

Do you always fully flood the carbs ?

It's 37 years ago but on my Triumph Bonnie with Amals I remember I would know roughly how many seconds it took to flood (say 5 seconds) and if the temperature was a little warmer mentally count some lesser figure in an attempt at partial flooding say 2- 3 secs. It started pretty easily on the kick start with those settings.
Title: Re: Starting an early bike with slider carbs
Post by: leswaller on March 08, 2012, 10:02:42 AM
Montmil
We are talking about a '72 R60/5, and yes, 5 or 6 attempts on the button. Incidentally timing (including centrifugal advance) and mixture are OK.

Barry
Yes, when cold I flood the carbs until they overflow. I also have a Velocette MAC with an Amal and have mastered the black art of starting that. The difference being of course that you can put your hand over the air intake  whilst cranking to suck fuel in before attempting to start the engine
Les
Title: Re: Starting an early bike with slider carbs
Post by: Ed Miller on March 08, 2012, 02:07:42 PM
Don't the older Bings have chokes?  Amals did, though most people (including some previous owner of my bike) removed them.

If the temp is below freezing my Triumph can take several kicks before it will stay running.  I generally kick it through once before turning the key on for another kick.

Title: Re: Starting an early bike with slider carbs
Post by: leswaller on March 09, 2012, 05:22:05 AM
Ed
No chokes on the old slider Bings, and of course due to the air intake configuration no way of strangling the air
Les
Title: Re: Starting an early bike with slider carbs
Post by: wilcom on March 09, 2012, 07:53:50 AM
As I recall my R50/2 from years ago had a strangle choke on the air cleaner, nothing on the carb except the ticklers
Title: Re: Starting an early bike with slider carbs
Post by: tvrla on March 09, 2012, 08:49:23 AM
The R60/5 also has accelerator pumps. Blip the throttle for an extra shot.

Kick it through two or three times (key off) to get the oil flowing and loosen things up, hit the kick start and it should fire right up.
Title: Re: Starting an early bike with slider carbs
Post by: Rob Valdez 79 R65 on March 09, 2012, 11:59:32 AM
Ed,

the 750 & larger /5's & /6's had CV Bings.  For some reason BMW decided to keep the slide carbs on the R60's.
Title: Re: Starting an early bike with slider carbs
Post by: leswaller on March 09, 2012, 12:06:53 PM
Wirespokes
 I think you are mistaken, there are no accelerator pumps on the slider carbs, they are just like the old Amals in operation
Les
Title: Re: Starting an early bike with slider carbs
Post by: Bengt_Phorqs on March 09, 2012, 12:24:15 PM
My '74 R60/6 had the CV Bings w/ the enrichener.  Never had a cold starting issue.
Title: Re: Starting an early bike with slider carbs
Post by: MrRiden on March 10, 2012, 12:40:33 PM
Just to add a some humor on something well covered by others here
http://www.stylekat.com/apparel/tshirts/detail/tshirt_amal.html
Title: Re: Starting an early bike with slider carbs
Post by: leswaller on March 10, 2012, 03:47:04 PM
"My '74 R60/6 had the CV Bings w/ the enrichener"
but regretfully the /5s dont  :( :(
Title: Re: Starting an early bike with slider carbs
Post by: Rob Valdez 79 R65 on March 12, 2012, 07:25:58 PM
Quote
My '74 R60/6 had the CV Bings w/ the enrichener.
Yep - I was wrong earlier when I said /5 & /6 R60's had slide carbs.  I was relying on memory.  Old memory...
Title: Re: Starting an early bike with slider carbs
Post by: tvrla on March 12, 2012, 11:47:43 PM
Quote
Quote
My '74 R60/6 had the CV Bings w/ the enrichener.
Yep - I was wrong earlier when I said /5 & /6 R60's had slide carbs.  I was relying on memory.  Old memory...
The 500s and 600s came with 26mm slide carbs. Any other carbs mounted to an R60 didn't come that way from the factory.

And Les, those slide carbs DO have accelerator pumps! They're located in the main jet and operated when the needle exits the jet. They're spring operated and when pressure is released, they spring out, sending a sqirt of fuel into the carb. Really simple!
Title: Re: Starting an early bike with slider carbs
Post by: Rob Valdez 79 R65 on March 13, 2012, 12:37:55 AM
Quote
The 500s and 600s came with  
Wow...and I forgot all about the R50/5
Title: Re: Starting an early bike with slider carbs
Post by: leswaller on March 13, 2012, 06:21:22 AM
Wirespokes
I owe you an apology, grovel, grovel, :-[  :-[ after replying to your previous post I have indeed discovered the accelerator pumps when I stripped one of the carbs in curiosity and amazement that maybe BMW hadnt thought of cold starts (which of course they had).
My only excuse is that this is my first BMW and I am used to British carbs with chokes.
Mia Culpa and my thanks for enlightening me
Les
Title: Re: Starting an early bike with slider carbs
Post by: tvrla on March 13, 2012, 08:59:04 AM
I was shocked and amazed the first time I discovered those accelerator pumps as well! I looked at those things and wondered what the hell they were??? The diagram said they were accelerator pumps - huh? How could that be???

They weren't working and it took a little while to figure out how they were supposed to work and get them operating again. Cool little items - clever guys, those Germans! But I think any grunge in the bowls or water can mess them up. When they're working, they're great!