I have a Yamaha 667 that I have had considerable work done to. I love the horn and am ready for the last step. I need to have the valves rebuilt, but don’t know how to narrow down the list of prospective repair shops who can do a good valve job. How do I choose someone to do this?
I’ve touched on this subject before (HERE), but let’s get specific about valve rebuilds. The short answer is, go to a shop with a good reputation and where they’ve done a lot of rotary valve plate and fit rebuilds.
Gather your information by first getting a short list of shops that do it. The list is, by definition, pretty short, actually. Once you get the list down to a manageable number, contact the technician (not necessarily the owner) who does the rebuilds and ask how many he or she has done. You don’t need an exact number, but there is a quantitative difference between “a few”, “dozens”, and “hundreds”. The more rebuilds one has personally done, the more experienced one is.
Next ask for two or three references and follow those up. Try to get references who’ve had the work done at least a year ago. You want to know how this work has held up over time. This is the most critical factor in your decision making.
Some technicians promote the equipment they have as a selling point, including plating tanks, high end lathes, and so forth. Just having the equipment doesn’t necessarily mean they do great work. But, having all the equipment ready to hand does mean that they can control the process more efficiently.
There will be other factors, such as price and location of the repair shop, but your choice should be decided primarily on the quality of the work. A good valve job can last dozens of years, and you want it to be of that caliber given the high cost.