So sorry to start another thread on this, but I need some advice. My R100s needs new valve guides, they are shot and having oil issues. the exhaust valves are also recessed and need to have the seats replaced. the valve is now flush with the seat. However the Intake valves and seats are fine. So on one hand I could replace everything with motobins valve kit and bmw seats for $300-$350 US or I could replace all four guides and the exhaust valves with kibble whites with bmw seats for ~$250 I have heard good and bad about both My main question: will the kibble white guide work with the stock Intake Valve? I read somewhere that the materials don't match up to well. Also having the local machine shop do the work as I know them and have had them do some for me before and all they do is engines. I trust em!
There is a scare going about over dimensions of the Elka valves and guides supplied by Motobins. Hopefully somebody in the know will confirm whether or not this is a genuine concern or not
Here are a couple of threads on the subject; http://advrider.com/forums/showthread.php?t=825135 http://advrider.com/forums/showthread.php?t=822323
I would only trust folks that do airhead heads day in and day out....Randy Long, Tom Cutter, Ted Porter, etc.
I know it sounds nuts, but I was in the same situation and did my own valves! I bought new valves, springs, guides and keepers from Motobins. They make a kit. I bought a spring compressor from Napa, took the valves out. Then I remember something about my wife being mad at me using her over to heat the heads and tap out the guides. Then I rented a Neway seat cutter and spent a few hours on it. I've been riding on those heads for 20k now with no problems. Compressions good, no smoke when decelerating. I just thought of it as a new challenge and if I got it wrong, I'd just send it off to one of the gurus mentioned in the thread.
That's awesome. I don't know if I would have the guts to try it, but glad you did and that it worked! Some things are mysteries that require the skills of wizards, but many can be done by motivated mortals.
I used this site for reference. http://jhau.maliwi.de/mot/head.html Drilling out the old guides enough to then punch out was the most time intensive part, but bronze drills easily. I just put my drill press on the slowest setting and mounted the head in a make-shift jig to hold it at the right angle. I actually did mine and another set for my uncle. Here's the kit I used. I did find this kit on Motobins.co.uk https://www.motobins.co.uk/bmw-parts.php?model=R Series 2 valve Twin&bikeref=R90-6 These valves are Swiss Intervalve and not genuine BMW. I'd read that pre-80's heads don't need new valve seats, so I didn't have to worry about that.
pssst, don't forget about bud provin (a member here) and an excellant wrench! he's not one to self-promote, so: www.thenickwackettgarage.com
Ted Porter at https://www.beemershop.com did all the work a few years back on my R90/6 heads when I was having the exact same issues as you. I couldn't say enough good things about his work. Very professional and knowledgable and took lots of time over the phone to tell me about what he was doing and why he does things the way he does them.
As much as I would love to try something like this, I am afraid it is to far beyond me. how did you do the guide reeming on those anyway I would love to hit up some of the guys doing beemer head work, my only issue is the shipping and then the waiting. I'm from Salt Lake, so I'm going to Love Machine Co. here. If they do good work then there's a new option for Utah guys. FTR the quote for all the work (4 guides, four seats, and four valve grinds,) was $280 and one week from receiving. I think that's not too bad. Im going to go with Motobins for parts, Moorespeed stuff is dang nice but, i don't need high end racing stuff....yet
That's awesome! I've installed new guides before, but never cut my own seats. I have 5 cylinder heads and couldn't justify the cost of buying them when I get charged $20 at the machine shop. I never realized you could rent them...have any suggestions on where to rent?
To return to the original post, don't get the Kibblewhite guides. They are very hard and must be sized with a hone. If you want to try this yourself get a guide that is ready to use when installed. CC Products (now a division of San Jose BMW) used to sell guides in that condition. I don't know if they still do. It was really a pretty good guide.
Guides need to be honed or reamed after installation to have a proper fit. The shrink or press fit will reduce the guide to valve stem clearance of a "pre sized" guide and it needs to be corrected.
Hm, how serious is that rob? I had new standard exhaust valve guides installed in my G/S heads a couple of months ago by a classic-vehicle engine restoration service. They've been in business many decades and I'd almost say I blindly trust their work, but they're not airhead specialists. Should I call them to check they did this? How much of a rehone and reaming are we talking about? Is it something I can check without the expensive measuring tools?
