The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Crossrodes on April 26, 2009, 12:59:55 PM

Title: R100 Intermitten Problem
Post by: Crossrodes on April 26, 2009, 12:59:55 PM

I have a friend (who has no computer) who has an intermittent problem with his R100.  These are the symptoms:

Occasionally it will run rough....shut it down and restart it and the problem disappears.

Other times when he comes to a stop it will idle very fast...again shut it down and the problem disappears.

I don't know for sure if the two problems are related but they seem to be.  He has checked all his cables and he says they are working fine.

I know I once had a problem like this with a car and it turned out to be a cracked vacuum line.  He says he is not aware of any vacuum lines like this on the bike.

Any thoughts???

Title: Re: R100 Intermitten Problem
Post by: Rob Valdez 79 R65 on April 26, 2009, 01:22:24 PM

What year?

I would look at the weights on the advance unit - make sure they are not sticking.  Clean and lube.  If it is a points model, make sure the rubber gasket is in good shape & in place.  Obviously check out the points while you are there.

And brushes...  ::)

Title: Re: R100 Intermitten Problem
Post by: MrRiden on April 26, 2009, 01:44:29 PM

Also what comes to mind is an intake air leak at the manifold rubbers along with Robs good suggestion. Are there a lot of deferred maintenance items on this bike?
rich

Title: Re: R100 Intermitten Problem
Post by: Crossrodes on April 26, 2009, 02:14:44 PM

Rob I know he converted to electronic ignition several years ago so I know there are no points.  However I'm not familiar with the electronic ignition...will there be weights with that unit?

MrRidden, I didn't think that the manifold rubbers would cause this.  Are you fairly sure that this would be a possibility?  I'm not sure how well he maintains the bike.  He probably only rides less than 5k Kilometers in a year.  

Title: Re: R100 Intermitten Problem
Post by: Crossrodes on April 26, 2009, 03:10:04 PM

I'm not sure what year it is and I can't get hold of him right now.  I'll find out the year when I talk to him tonight and I'll pass this info along.  Thanks for your advise.

Mike

Title: Re: R100 Intermitten Problem
Post by: Bob_Roller on April 26, 2009, 03:22:53 PM

I'm wondering if the electronic ignition that was installed, is a non-OEM type system, and may not use the 'bean can' that's installed.

To convert to an OEM electronic ignition, would require a bit of re-wiring.

Title: Re: R100 Intermitten Problem
Post by: Crossrodes on April 26, 2009, 07:20:52 PM

I just spoke with my friend and gave him the list of possibilities.  Montmil his bike is a '77.  He does not believe that he has springs under the carb tops.  Is this something that can be added and where would he get them?

Title: Re: R100 Intermitten Problem
Post by: Justin B. on April 26, 2009, 07:59:00 PM

Quote

Other times when he comes to a stop it will idle very fast...again shut it down and the problem disappears.

This is a classic example of advance weights sticking, usually due to rust.  The 77 stock would have had a points-plate and something tells me that the timing chain cover and cam and stuff might need to be changed to install a "beancan" ignition sensor.  That said it might be an aftermarket gizmo of some kind.  Sooo, if this electronic ignition sensor mounts to the plate in place of the points (like a Pertronix unit) then the stock mechanical advance/flyweights should still be there and might need to be cleaned and lubricated.

On the other hand, I really don't know what I'm talking about although I did stay at a Holiday Inn Express once...