Hi,
Part 2
Yamaha do not use many machine-specific special tools, and problems as they arise, with careful and creative thinking can often be overcome.
Your most useful tool could be a competent friend, but beware of "mechanics" whose own machines don't run sweetly, leak oil, rattle, clatter and make other strange noises, have chewed-up screw heads, and have gasket goo squeezed out from between the joints.
Even if you have to spend £200 on tools (£200 worth of Draper Expert tools would cost £800+ if you had to have Snap-On, for example) consider these an investment as you can use them again and again. And again and again and again. Like Jane. I still have and use tools I bought or was given as much as 40 years ago.
The parts cost should not be high as the gaskets for side casings could be re-used and bearing and seal could be as little as £20 from a bearing specialist to around £50 for Yamaha parts. If disassembly is done with care (as it should be) and gaskets sticking to both faces are teased from the faces using a thin steel rule as the casing is being removed few other parts should be needed.
Great care should be taken at all times and cleanliness is extremely important. Do not rush the job, especially re-assembly.
If the machine is not fixed, its value would be substantially reduced; even more so if it starts to leak oil, or if the gearbox fails completely. It really is a case of "a stitch in time saves nine" as if it is attended to soon enough, the other bearing on the shaft should be ok.
Take it to a Yamaha specialist, ask their opinion and get a price for the job. You will probably find that a £200 tool cost is about one half to two thirds of the labour charges estimated depending on where you live.
If your son learns how to maintain and repair his own machines properly, much money can be saved by doing it himself, providing it is done well.
Personally, I started "spannering" as soon as I started riding pushbikes as my dad had a very good toolbox, and a bench and vice in the shed, and was of the opinion that if I wanted to ride it, I would have to learn to fix it. At eight. So I suppose that gives me an "advantage" over those with the funds to "have it repaired" at the local shop.
A local Technical College in your area may run a short course on motor or motorcycle engineering which could be useful for learning new skills - I knew a girl who, being a student and being sick of getting ripped off by more than two or three small repairers especially for MOT preparation, enrolled at the local tech at my instigation. She is now quite competent at general work and has enrolled in a "Recreational Metalwork" class to make special parts for a custom bike she is building.
I assume from your "handle" that you are Ben, a BSA enthusiast, who has no experience of Japanese machinery, but some of British bikes. If that is the case, don't be put off. But equally, don't assume (as I believe you don't) that all practices considered acceptable for old British machines are ok for Jap. bikes. Use of an accurate torque wrench, for example is more than just good practice, it is essential. This is a tool I had never heard of before starting to work on Japanese bikes.
If you have ever successfuly fixed anything on your Brit. bike, then have a go. Conquer your fear of multi cylinders, horizontally split crankcases and overhead camshafts. You might find some truth in the opinion held by many that Jap. bikes are easier to work on than Brits. I think that they are just different.
Finally, don't start the job unless you are going to persevere and finish it, and don,t make do with shoddy workmanship by yourself. Remember, its yours, and if it breaks or "lies down" on you, you're the one who has the indignity of walking home with a red face or cadging a lift from some gloating rider who's opinion is that it can't or won't happen to him 'cause he gets some shop to do his work (at £50 or £60 an hour), or he only buys bikes with warranty so they'll be fixed "for free".
These are my own opinions and I appologise for rambling on, but I do hope someone somewhere, if not yourself, gets something from this.
But I do hope it helps you.
The best of luck to you,
A.