Timing

[ddebonis]

My '84 R65 has electronic ignition. I'm doing a tune-up for the first time and figured I'd check and set it even though the manual only calls for this every 10k miles.

I'm not buying BMW's $180 timing box for static timing. My friend has a timing light to do dynamic timing.

If anyone has any tips for doing this just incase the R65 is quirky, please let me know.

Thanks!

Danny

[montmil]

To alter ignition timing, you'll need to remove the front engine cover after disconnecting the battery's ground cable. Replace the ground cable when the front cover is off.

The bean can must be rotated to alter the timing. Don't get it so loose that it jumps around by itself; you want to be able to rotate the can to set timing. Then snug down the ITC and double check with the light one last time.

Best to confirm and/or set valve lash before checking timing, Incorrect lash settings can mess with timing results. Engine should be well warmed up prior to hitting the flywheel with the light.

Timing light induction lead on the right-hand cylinder plug wire.

Power the timing light with a battery other than the one under the seat. Shop battery, car, your neighbor's riding mower, what ever. Just a good 12v.

Check your shop manual for the meaning on the flywheel markings. They will be easier to see during the timing exercise if you first dab some white paint into the stamped letters, then wipe off the excess.

Enjoy.

[ddebonis]

Thanks!

Out of curiosity, do you know why we're supposed to place the induction lead on the right-side?

What happens besides drained battery if I use my bike's battery to power the timing light?

[montmil]

Right-side spark plug cable is used per manual.

At idle, your battery is getting little or no charge. A separate battery will deliver more consistent timing light performance. Sayeth the manual.

[nhmaf]

soemtimes a cheap timing light will give errant pulses from the noise spikes on the motorcycle being tested - giving the timing light a clean, stable source of power will usually improve the results.   You *can* run the strobe from the battery on the bike, but if you get really funky results, well, it might be the light, or it might be the bike (if it isn't running well).   A separate "clean" power source removes that possible variable.

[Ed Miller]

You should get the same timing mark with either plug wire.  I always check both, because if they don't flash at the same time there's something interesting happening, probably with the timing chain.

[ddebonis]

Thanks y'all.

I just discovered I have a more serious issues, potentially. My bike sometimes idles HIGH, like 2k... It's usually after riding it around for a while. I can get it to drop by slowly engaging 1st gear.

I heard from my mechanic that the electronic timing bean can has springs inside that wear out. So, with centrifugal force, the timing advances (sooner than it should) and doesn't retard when the engine slows down. This could cause the high idle... and will prematurely burn my exhaust valves. I just got new throttle cables because current ones are frayed so I hope that may fix the issue. But if not, these bean cans are EXPENSIVE and very hard to find.

How are others dealing with this? Is there a fix? Anyone know where to get replacement springs and service the bean can??

-Danny

[montmil]

Danny, Your high idle could be caused by one or more issues.

The frayed throttle cables would be the primary suspect. Replace the cables first before doing anything else. Making multiple adjustments/alterations without checking the performance of each change will leave you with no clue as to what was the correct fix. Dig?

I might have to toss the red BS flag on your mechanics diagnosis of worn out advance mechanism springs. If there is a problem with the advance system in the bean can, it most likely would be that the advance weights are sticking on their pivots and are not retracting fully. The weights have tiny nylon 'shoes' which swing in n' out on a smooth surface plate. Again, gummy oil or dirty interior could be the cause of the idle not returning to correct levels.
   By dragging the clutch to reduce revs, you may also be allowing the advance weights to fully retract. Next time this occurs in a spot where you can stop for a minute or two, do not drag the clutch but shut off the engine without touching anything. Nothing. Turn the key back on and hit the starter without touching throttle or anything. Report your findings.

Finally, when the Airhead engine is well warmed up after 20+ miles (depending on weather conditions) that's when you'll get a good indication as to how well the idle mixture screws have been set.  Setting idle revs on a less than full operating temperature engine is an exercise in frustration.

All the carb tuning in the world will be for naught if the Bings are not perfectly clean, all jets and passages clear,floats set correctly and enrichener circuits working.

[ddebonis]

Yes, hopefully the new throttle cables fixes this. I assume replacing this is straight forward...

Perhaps I misinterpreted what my mechanic said. That said, is it possible to service the can and clean the oil/dirt that is causing the weights to stick?

I'll take a ride today and perform the procedure you described.

I believe my carbs to be clean. Bike runs well, currently. Opened the bowls and they were nearly spotless.

[nhmaf]

To some extent, the bean cans can be serviced, but it is a more "advanced" topic -- don't go there until you've eliminated the simpler, easier items such as the cable, making sure your valves are set properly, and carbs are synched after the engine has been well warmed up.  Failure to comply with any of these things can also result in high idle or varying idle speed when the engine warms up.

[montmil]

[size=18]+[/size] [smiley=thumbup.gif]   Yep. What Mike sez.

To some extent, the bean cans can be serviced, but it is a more "advanced" topic -- don't go there until you've eliminated the simpler, easier items such as the cable, making sure your valves are set properly, and carbs are synched after the engine has been well warmed up.  Failure to comply with any of these things can also result in high idle or varying idle speed when the engine warms up.

[Red_Hen]

Suggest wearing a heavy glove when Rotating bean can to adjust timing - easy to burn hand on hot exhaust - BTDT!

[Julio A.]

I have the same problem before. High idle that goes down when you feed the clutch, when put down, it stays there. When you give some throttle, it has difficulty getting below 2k again.

It was just a too lean of a fuel mixture at idle. Fixed it with a few counterclockwise turns on the a/f mixture screws on both sides.

And +1 on wearing gloves. I got continuously electrocuted and consequenly got  burned on the exhaust pipes when I did the timing during a heavy rainfall. During the monsoon season here, even under the shade, the air was so humid it was conductive!

[Barry]

Fixed it with a few counterclockwise turns on the a/f mixture screws on both sides.  

Julio,  

You surely don't mean full turns ?

[jusgus]

Gloves? How about long sleeves preferably leather or cotton . I have two temperature vaccinations and keep reminding myself how much money I saved by not having them tattooed. I know, once burned twice shy, but one doesn't necessarily have to be very bright to work on an airhead.