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Is there a way for a novice to know if the heads on a 78R100/7 would benefit from reconditioning? Bike is using about a qt of oil every 1k miles. Faint white smoke and strong smell of exhaust/gas when running. I have removed the carbon from the piston crowns and conbustion chambers. If they need work where do I send them? I know about Bob's but are there other options? I know this is an open ended question but I have to start somewhere. Thanks

Compression or Leak-down test, the latter being more useful, IMO.

If the valve guides are worn, particularly the exhaust, the rocker arm area of the head and valve cover will be brownish colour rather than clean cast aluminium. That is from blow-by baking a bit of oil on the surfaces.

Edit, exessive carbon build up is ususally as sign of bad rings. If realy bad, the squish band area of the piston will be very clean with a heavy black build up next to it.

Not used him, but plan to. Seen him recomended a lot.

Randy Long
74 Risbon Road
Honey Brook, Pa. 19344
610-286-5870


I have also read that he uses/recomends Black Diamond Valves. Just FYI.

Randy Long good work good price pleasant to deal with.
Guy

My '78 R100/7 heads are going to Ted Porter at the Beemershop in a month or so. He used to work at Bob's BMW and was the "head" man there...he also began using Black Diamond valves but his experience, at least with the early version of those, was not very good. I got info from him recently and he uses OEM parts for his head work.

Kurt in S.A.

I highly recommend Robert Grauer in San Jose for head work. He knows these heads like the back of his hand and does great work. He just did the heads on my slash five, including dual porting and shaving the heads down. The bike runs great and has yet to show signs of oil consumption. Send me a PM if you need to get in touch with him.

Prices depend on what is needed, but his prices are reasonable. If you shop around, you may want to inquire about turn around time.

Wasn't the issue of using Black Diamond valves a matter of clearance ?
I have never used them, but was at a seminar to hear an extensive debate that concluded:
1) BMW guides won't work with Black Diamond valves.
2) BMW valve / guide specs (as per stock parts) won't work with Black Diamond valves & Amco 45 guides .

Black Diamond / Kibblewhite valves are one-piece stainless instaed of BMW's inertia welded head to stem,

I only mention this as BD valves will have a bad rep in certain circles,
but are used elsewhere with good results.

My understanding was that the part of the stem that went through the guide was rougher than others, resulting in excessive wear and/or sticking. Ancedotally, I remember a couple of dropped valve situations and they were BD valves.

Kurt in S.A.

michael wrote:Is there a way for a novice to know if the heads on a 78R100/7 would benefit from reconditioning? Bike is using about a qt of oil every 1k miles. Faint white smoke and strong smell of exhaust/gas when running. I have removed the carbon from the piston crowns and conbustion chambers. If they need work where do I send them? I know about Bob's but are there other options? I know this is an open ended question but I have to start somewhere. Thanks

Re: valve guides...at night, if stopped at traffic lights at idle, with cars behind you with their headlights on, watch the rear vision mirror for smoke, especially as you accelerate at normal speed. Smoke is likely to indicate the guides need replacing. Lotsa smoke just about confirms it.