'79 R 100 RS Cylinder Heads

[Kannon]

I'm looking at a '79 R 100 RS that's in fairly good shape. I noticed that it had dual plug heads on it and don't think these were standard items from BMW back then. If someone went to the expense of dual plugging the heads what other modifications would they be likely to do, and what should I look for? The current owner knows nothing of the mechanicals.

Also, what problems would dual plugging solve, would this have been done along with higher compression pistons or some other modification?

 

Thanks,

[Woodie]

Dual plugs would offer more power, cleaner (faster) burn. In the RS, I would look for higher compression as well.

 

Check out SnowBums pages, or the AirHeads.org (?) site for more info.

 

[too old to care]

Since they have the dual plugs, probably hardened seats for unleaded gas too. To get the best out of the dual plugs, it most likely has a Dyna III ignition. This ignition has hotter spark and no points, thus it is virtually maintenance free. Other common mods were lightened wrist pings, rebalanced rods, and a general cleaning up of the upper end.

 

Look for other signs of upgrades too, such as fork brace, upper triple clamp, new shocks (Koni), and beefed up swing arm. These were all popular mods for this vintage bike.

 

I have a 78 with the same mods, plus more. Great machine will never let mine go.

 

[Kannon]

Thanks for the information. The seller is going to bring the bike to my house tomorrow so I can check it out in my shop. I'll let you know if I find anything else interesting - his price is a bit high considering the cosmetic condition of the bike but if it seems mechanically sound there may be one more bike in the barn -

 

Bruce