The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: AndrewB on December 22, 2009, 09:44:32 PM

Title: High Idle
Post by: AndrewB on December 22, 2009, 09:44:32 PM

On my commute home the last few nights I've had a excessively high idle.
This happens after 15 minutes of riding and bringing the RPMs up to around 4500 RPM.
After that the bike will rev up to a constant 2500-3000 RPMs when idling.
I did a spline lube last week. That went well w/ no problems, the bike drove fine and idle was good for over a week.
Any advice on what to look for would be great.

Title: Re: High Idle
Post by: montmil on December 22, 2009, 09:50:45 PM

What year and model?

Check timing and operation of the advance weights. Advance mechanism may need cleaning and lube.

Confirm correct throttle cable adjustment and cables not snagging on something. Check cable junction tube, if so equipped. Read: free operation. Sticky throttle gears.

Possible carb diaphram issue/s.

Yous guys got any more ideas?     Monte

Title: Re: High Idle
Post by: AndrewB on December 22, 2009, 10:35:34 PM

It's a 84 R65.

Thanks for the advice.

I'll report back w/ what I find tomorrow.

Title: Re: High Idle
Post by: bruce_launceston on December 23, 2009, 04:11:17 AM

If you haven't been adjusting the carbs or had your twist grip apart I would first check all the cable seats, as Monte suggested, making sure none have jumped out and then check for a fraying / snagging throttle cable. On the '84 with the cable splitter there are lots of places things could go wrong. Also check that both cable return springs are still there on the back of the carbs?

Title: Re: High Idle
Post by: Lucky_Lou on December 23, 2009, 01:57:18 PM

Dumb question.....is the "choke" shutting off ??
Lou

Title: Re: High Idle
Post by: AndrewB on December 23, 2009, 09:48:26 PM

Checked all the cables from the choke & throttle to the carbs. Everything looks good and moves well.
Monte's suggestion of sticky advance weights seems very probable.
I need to pick up a timing gun to confirm it.
I found these two articles on rebuilding the ignition canister.
http://bmwmotorcycletech.info/Ignition.htm
http://www.deathstar.org/~flash/ig_trig.html
The "deathstar" article has a link w/ pictures to boot!
Anybody have any experience rebuilding the ignition canister?

Title: Re: High Idle
Post by: Rob Valdez 79 R65 on December 24, 2009, 12:03:05 AM

Yes, The Flash (deathstar.org) has everything you need.

For entertainment (good entertainment), I highly recommend his book, Gathering Speed - Tales of Motorcycles and Life.

Quite a character.  A G/S lover from day one.


Oh, and I found this thread http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1256755915/38#38

It is from a couple of months ago.  There is stuff to read before the pictures start.

Title: Re: High Idle
Post by: Semper Gumby on December 24, 2009, 08:26:57 AM

Don't forget to check the exhaust valve clearence.  When they tighten up they idle faster due to dreaded recession. :P

Title: Re: High Idle
Post by: Rob Valdez 79 R65 on December 25, 2009, 05:09:46 AM

You asked for information on rebuilding a bean can.

The links you have will walk you through it.

One of the little things is BMW does not sell the springs for the advance weights.
While you are in there, it is nice to replace them.
You can get new ones from Motobins in England.  Fast shipping at a minimal cost on a small item like this.
I bought two pair, just 'cause.

http://www.motobins.co.uk/displayfinal.php?s=0&function=show&subs=192&title=ADVANCE+RETARD+SPRINGS%2FUNITS&model=

Title: Re: High Idle
Post by: AndrewB on December 25, 2009, 07:32:30 PM

Happy holidays to everyone and thanks for the info.

With family in town there is no way I'm getting into the garage.

So this project is going to be on hold til after the new year.

I'll report back then.

Andy

Title: Re: High Idle
Post by: AndrewB on January 19, 2010, 12:19:21 PM

Well I finally got to rebuild the bean can. I took Rob's advice and ordered a new set of springs from Motobins.

Everything went well w/ the rebuild. I found the "Deathstar's" directions easy to follow.

I put the ignition canister back on.

The bikes idle is higher now right after starting (approx 1500 rpm).

Is this because the ignition canister is now lubed and working smoother?

Anyone know if this normal after a rebuild?

Title: Re: High Idle
Post by: Bob_Roller on January 19, 2010, 12:34:06 PM

If everything else checks out correctly, adjust the idle with the throttle stop screws on each carburetor .

I think 1200-1300 rpm for idle seems to be a general consensus among riders .

Ride it, and see how it runs .

Title: Re: High Idle
Post by: Rob Valdez 79 R65 on January 19, 2010, 04:59:25 PM

AndyB,

Do you have the manual that came with the bike?  That has step-by-step instructions on setting the timing, and idle, and adjusting the cables.

Everyone should have a copy of this book.

Title: Re: High Idle
Post by: AndrewB on January 19, 2010, 07:14:41 PM

No I do not have one, I need to track one down.  

I have the adequate but sometimes vague Clymers manual.

Title: Re: High Idle
Post by: Rob Valdez 79 R65 on January 19, 2010, 09:35:56 PM

For now, try this link:

http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1212944300