carb balancer

[AdminGuy]

Darryl - how do you like the twinmax carb balancer? Looks good compared to my home made vacume guage job.

[darrylri]

The Twinmax is a well designed unit. Like a homemade manometer, it shows the vacuum balance between two cylinders. Unlike a manometer, it doesn't use mercury or six feet of tubing and water. It can sit on the seat or gas tank of your bike while you work.

It has a sensitivity knob to control how wide the differential swings are on the guage, so you can start out with it at half sensitivity to bring the carbs into rough agreement before turning it up full and tuning it to a T.

It takes a 9V battery and has a lighted guage -- don't forget to turn it off when you're done!

I also have a vacuum guage from JC Whitney for use on my pre-70 BMWs, whose carbs don't have a vacuum port. This is not as fine an adjustment, but works for me. The guage was about $25 and has a rubber tail piece. You hold it against the intake of the carb on one side and read the guage; then hold it against the other side and compare. You can't use it to synchronize the slide "lift off", however.

[HarleyCreation]

Darryl:

Do you have any experience balancing the intakes on the K100 BMWs? Like can a guy do it himself with the right gauges?

(I would have said "injectors" but I'm afraid that I'd get kicked off the Forum for using such a modern term.)

Thanks!

[darrylri]

No, I haven't got any experience with the brick motors, I have only ever owned boxers. Because of the close mechanical linkage on the K bikes, they're not supposed to get out of synch.

There are a lot of DIYers in the BMW community. A quick look over at http://www.ibmwr.org on their tech pages indicates that there's apparently no trick to synching the "intakes" ;-), so perhaps all you need is a Clymer or BMW manual to do it.

[HarleyCreation]

Originally posted by darrylri
No, I haven't got any experience with the brick motors, I have only ever owned boxers. Because of the close mechanical linkage on the K bikes, they're not supposed to get out of synch.

There are a lot of DIYers in the BMW community. A quick look over at http://www.ibmwr.org on their tech pages indicates that there's apparently no trick to synching the "intakes" ;-), so perhaps all you need is a Clymer or BMW manual to do it.

Thanks.

I've seen those sites, but just thought you might have dabbled with the K bikes.

I don't know that my "intakes" are off, but my bike does have a rattle that one guy on the Flying Brick Forum thought might come from out-of-balance tuning. Another guy thought maybe just a exhaust rattle. My worst fear is a timing chain rattle ($$$$). But until the weather warms up and I can get it back on the road to investigate further, the exact cause remains up in the air....

[darrylri]

Check the exhaust heat guard and also the weld where the headers meet. Those are both prone to cracking and rattling on the K100s.

[HarleyCreation]

Originally posted by darrylri
Check the exhaust heat guard and also the weld where the headers meet. Those are both prone to cracking and rattling on the K100s.

I crawled around on the cold stone floor inspecting K100 yesterday and could see no problem with those units.

[darrylri]

It's probably good that it wasn't either of those items. But unfortunately, you've now fathomed the depths of my knowledge about K100s.

The only other things I know about them is that the instrument pod is prone to condensation, and if dirt gets into the starter clutch, then the bike won't start (but there is a get home fix for this: roll the bike around while pressing the starter button and it will likely catch).

[HarleyCreation]

Originally posted by darrylri
It's probably good that it wasn't either of those items. But unfortunately, you've now fathomed the depths of my knowledge about K100s.

The only other things I know about them is that the instrument pod is prone to condensation, and if dirt gets into the starter clutch, then the bike won't start (but there is a get home fix for this: roll the bike around while pressing the starter button and it will likely catch).

Darryl,

You know plenty!

Researching K100 cam chain stuff some more, it seems that usually it's not the chain itself that needs replacing, but two pieces in the tensioner unit. At least the cam chain seems easy to get at if that turns out to be the source of the noise.