Head Repair

[D Mann]

Just finished replacing the timing chain and went to adjust the valves. Left side no problem, right side no clearance even with adjusters backed all of the way off. Yes I rotated the engine 360 deg and watched the valves close. I need some recommendations for a shop that can do a good job on the heads without breaking the bank. I am in northern Illinois.

[Matt Chapter]

I need some recommendations for a shop that can do a good job on the heads without breaking the bank.

Common suggestion, although I'm not familiar with your neck of the woods: air cooled VW mechanics.

When I had my head worked for a broken exhaust valve, worn guide resulting from same, etc, I went through my "un-affiliated" air head mechanic.  He's a bit of a unique guy, but has the knowledge and connections to get the job done.  There may be a similar individual around, especially in the Chicago area.

If you want to investigate shipping to the ATX area, check out http://www.ororcycle.com

[montmil]

Two of the very best Airhead head repair and overhaul:

West coast: Ted Porter's Beemer Shop   http://www.beemershop.com/

East coast: Tom Cutter's Rubber Chicken Racing Garage http://www.rubberchickenracinggarage.com/

Neither are "economy" shops and both gents are usually booked 5-7 months ahead for head work; particularly now that Spring has done Sprung. Prices hover near $600-700/pair for total refreshing and all new parts.

An alternative is to check eBay. Sometime years back, I purchased a pair of prefect late model R65 heads off a bike that had massive front end damage and was being parted out. Even the exhaust stub threads are virgin-like. $130.00 the pair.

[Tony Smith]

In this case it would seem to be valve seat recession, there is no cheap fix as the head needs to be welded up and then cut so a new seat can be pressed in, then the guides need to be done, new valves (probably get away with exhausts only) cut (minimum 3 angle) and grind.
 
If you are bucks down, a serviceable set of 2nd hand heads is an option but measure the guide clearance (a set of k-lines can be fitted cheaply and will last almost as long as new guides) and then monitor them closely. Any heads manufacturer pre-1985 may suffer from seat recession when used with unleaded or low lead fuels - there seems to be no rhyme or reason, some will recede and some will not. I dose my fuel with a lead replacement - costs me about $2.20 per tank of fuel, I regard it as insurance and as a hedge putting off the evil date I have to fit hardened seats to the exhaust valves.

[D Mann]

Thanks for the tips I will do some checking.

[D Mann]

Well I called a few places and Brunos in Canada looked like the quickest turn around at about 7 weeks. I pulled the exhaust and rotated the engine to see the valve through the exhaust port and suddenly there was a lot of valve clearance. I made a newbie mistake!!!! I had been watching the cam sprocket to rotate 360 deg instead of the crank sprocket. I never had my left cylinder at TDC on compression. Well I re torqued everything and there is plenty of adjustment. Sure glad I caught my mistake before I spent big money.

[montmil]

2:1 ratio on crank and cam rotation. Swell. Now he tells me!

Good you caught this now. Otherwise, you'd be buying new big n' little o-rings, a pricey head gasket and a pair of pushrod tube seals. Plus, if you don't have one, a torque wrench... which you should buy anyway.

[tvrla]

You do know there are marks on the flywheel for this? There's a black rubber plug behind the left carburetor covering a 'window' to view the flywheel. There's a tab on the flywheel with OT marked on it - translation = Top Dead Center.

[D Mann]

Yea I know, I just got caught up in cranking it around and watching the easy to see mark on the cam chain, lets face it, I had a brain fart but recovered before any damage was done.

[RWKuechen]

I just had a set of 1979 R-65 heads re-done (and updated). Contact Leo Goff at Memphis Motor Werks.  Not cheap but I had the exhaust stubs re-done and the heads rebuilt and they came back in about 6 weeks looking like some kind of Mechanical Pornography.  The bike is finished and it runs like a champ.  Excellent Value for Money. Highly Recommend. Very Professional.

[Justin B.]

Dang, I always put my thumb in the sparkplug hole and when I feel compression I poke a drinking straw through and use it as a TDC indicator as I "bump" it...

[decorn33]

Hurray! I'm not the only one to use the thumb over the sparkplug hole - feel for compression - check for TDC with a straw approach. I even have a dedicated straw.

[Tony Smith]

Hurray! I'm not the only one to use the thumb over the sparkplug hole - feel for compression - check for TDC with a straw approach. I even have a dedicated straw.

I still have one of these ancient things (micro-time) dating from the time when setting timing was a black art.
 
books.google.com.au/books?id=SNgDAAAAMBAJ

[montmil]

Tony, I too have a vintage Micro-Time tool. Still have the booklet that came with it -giving what mark on the plunger should be 'locked in' for timing a Yamaha DT-1, etc. Been in my tool chest for over 40 years.

[Tony Smith]

Tony, I too have a vintage Micro-Time tool. Still have the booklet that came with it -giving what mark on the plunger should be 'locked in' for timing a Yamaha DT-1, etc. Been in my tool chest for over 40 years.

Mine was purchased to use on a Bultaco Sherpa-T, 1975 seems a long, long way away now.....

but i think you are a few years older than me.