BMW R80 ignition timing advice

Discuss all things 1970 & later Airheads right here.
Post Reply
Leonweer
Posts: 4
Joined: Tue Apr 30, 2024 4:04 pm

BMW R80 ignition timing advice

Post by Leonweer »

Hello I'm Leon from the Netherlands and new here on the forum.

I did some maintenance on my R80 and when I checked and correct the timing of my ignition I've noticed that the ignition hall sensor is turned maximum counter clockwise. Actually he has to go a little further for a 100% correct timing
20240429_174346.jpg
20240429_174346.jpg (1.83 MiB) Viewed 1075 times
I did this with around 900rpm. Is this normal or could there be a reason that the hall sensor is in this position?

Regards
Leon
User avatar
gspd
Posts: 1041
Joined: Tue Aug 03, 2010 8:04 pm

Re: BMW R80 ignition timing advice

Post by gspd »

Timing chain most likely shot.
In the mean time....
Adjust the timing for Z (or F) mark at +3000 rpm.
Mechanic from Hell
"I remember every raging second of it...
My bike was on fire, the road was on fire, and I was on fire.
It was the best ride ever!"
Leonweer
Posts: 4
Joined: Tue Apr 30, 2024 4:04 pm

Re: BMW R80 ignition timing advice

Post by Leonweer »

The Z mark with 3000rpm is with the same hall sensor right?
User avatar
gspd
Posts: 1041
Joined: Tue Aug 03, 2010 8:04 pm

Re: BMW R80 ignition timing advice

Post by gspd »

Not sure I understand your question. There is only one 'beancan hall sensor' to adjust. Adjust the beancan so you have the Z mark at over 3000rpm.
Mechanic from Hell
"I remember every raging second of it...
My bike was on fire, the road was on fire, and I was on fire.
It was the best ride ever!"
Leonweer
Posts: 4
Joined: Tue Apr 30, 2024 4:04 pm

Re: BMW R80 ignition timing advice

Post by Leonweer »

That was my question, thank you.
I will try this
User avatar
melville
Posts: 1815
Joined: Tue Aug 03, 2010 8:32 am

Re: BMW R80 ignition timing advice

Post by melville »

What gspd is saying is that timing at speed is more important than timing at idle. Make sure it's right for the conditions that could actually damage the engine if timing is wrong and let the idle timing fall where it may.
Call me Mel. Some years ago- never mind how long precisely- having little or no money in my purse, and nothing particular to interest me at home, I thought I would ride about a little and see the other parts of the world.
Leonweer
Posts: 4
Joined: Tue Apr 30, 2024 4:04 pm

Re: BMW R80 ignition timing advice

Post by Leonweer »

Ok I do understand,
I did the check with 3000rpm for the "Z" mark and it looks like the same by idle "S" mark. It needs a bit more adjustment to be spot on.
Rob Frankham
Posts: 1214
Joined: Thu Aug 26, 2010 2:11 pm
Location: Scotland UK, 20 miles from civilisation up a dead end road!
Contact:

Re: BMW R80 ignition timing advice

Post by Rob Frankham »

A couple of questions...

Is the ignition system on the bike completely original. Some aftermarket systems institute a delay in the impulse (for various reasons)?

Have you ever checked the timing (I mean personally) and been able to set it up correctly?

Has any work been done on the engine (or the bean can) that could affect the timing?

On the face of it, the problem you are experiencing can only be due to the engine or to the sensor unit. The only adjustment is the position of the sensor unit.

Personally, I would like to try another sensor unit... not because I think a fault in that unit is likely but because it's the easiest thing to eliminate.

That being eliminated, I agree with GSPD that the probable cause is likely to be a worn timing chain. Something I wouldn't want to ignore for too long because, if it's that far out, the chain is very worn and eventual complete failure can't be ruled out.

Rob
ImageImageImage
Kurt in S.A.
Posts: 1647
Joined: Tue Aug 03, 2010 12:08 pm

Re: BMW R80 ignition timing advice

Post by Kurt in S.A. »

Curious...how many miles on the engine?

Kurt
Post Reply