"Old Bike Restoration Experience" by Richard Casey

The following article is something I decided to write since I figured there's got to be other DVNR members that are tinkering with old bikes that don't happen to be Nortons but are worthy steeds none the less. By that I meant people other than ME!   Most DVNR folk know me because of the Nortons I've owned and repaired for the past years but there is another piece of my bike fixing story that doesn't include Nortons. That piece has been both fun and educational as well. So, on to the present which includes tinkering with a non-Norton that is an interesting machine none the less. The bike in question is  1982 Yamaha XJ650RJ Seca a friend sold me for a pittance. This bike is one he bought in 1982 at my recommendation because at the time, it was highly regarded by the motorcycle press for its comfort, power, handling and shaft drive. So, 29 years later he sells it to me because it hasn't run in 12 years. And that there is the reason for this article; bringing life back into a bike that's been dead a long time. There are so many such bikes just like this one that have been abandoned but not discarded because they are really nice bikes! I'm referring to bikes like the first Kaw 900 Ninjas, Suzuki GS 1000's and many other decent bikes that were the Superbikes of the time just a few years after England had stopped making Nortons and Triumphs.  These bike are now also real 'old bikes' deserving of the repair and re-use that we bestowed on our sacred British iron.

But dealing with these 'later classics' is somewhat different the shaping up a Norton or an old 500 Daytona. The parts scene is different and the bikes are way more complex. That said, I thought it might be useful to write about my project Yamaha 650 Seca and share some of the problems and solutions I encountered along the way. The bike is not quite ready but is very close to its maiden voyage.

What you usually end up with

Bikes that sit for long periods of time develop a number of ailments the worst of which is rust. Rust occurs everywhere, in places you can see and places you cannot, like cylinder walls, battery boxes, gas tanks, expensive-to-replace mufflers, exhaust system junction boxes  ($$) among other things. Japanese bike parts can be really expensive and there is not a big after-market for the stuff you really need.   This means you need to be very selective regarding which Japanese (or European) oldie you pick for your project.  Norton parts are cheap and plentiful by comparison.

The one area that is particularly challenging is the carb setups on transverse 4 cylinder bikes. Four of everything and after sitting for a zillion years these complicated Hitachi or Mikuini carbs will be seized and plugged with solidified varnish that does not go away with a simple spritz of Gumout. All the carbs on my Seca had to be scraped clean with an Exacto knife and all the jets replaced. The throttle butterfly shaft was seized and the float needle and seat were encrusted. Fortunately the slide diaphragms on the CV carbs were in perfect condition as were the slides, carb bodies, slide needles. The parts were all of very high quality but gad zooks were these things a bitch to clean.

One lesson I learned and should have considered from past experiences, is that just because some big name parts supplier sends you the 'right parts' doesn't mean you actually have the right parts. I encountered this upon attempting to start my Yamaha with its freshly rebuilt carbs only to be faced with a frustrating 'No Start' situation. How could that be, everything is new and squeaky clean. Hmm. So being the skeptic that I am, I reminded my self that I had not actually compared the new carb parts to the old ones so I better do so. Off came the rack of 32mm Hitachi carbs and into the float chambers we go. Let's look at the float needle old and new ... and what do I see?  The new needles are an eight of an inch longer than the old ones!  This means that the float level in the carbs is too low to energize the start circuit of the carb. I was thrown off initially because the bike started and ran if I squirted starter fluid in the venturi area. But it was the incorrect needles that did me in.

So, new shorter needles, no problem? Think again. The needles I got were the only ones available so I had to make them work. Fortunately I devised a way to reshape the float tang so that the float lever would accommodate the longer needle. It worked perfectly and the bike now start and runs like it should.

The point of all this is simply that new parts aren't always an easy swap. Failure of an engine to behave the way you expect it to stirs doubt in your own repair process and can even point you in the wrong direction looking for a cause. If that happen to you, check the obvious things first and be sure to observe as many clues as possible that may point to a problem.

The other fuel-related issue that plagues most dead, old motorcycles is the rusty gas tank. The one on my Seca had some gasoline in it, so I was hoping that would protect the tank to some degree and it seemed to have done so. But there was still lots of rust particles to be dealt with. I decided the best way to scrub the inside of the tank was to use a 4 foot long piece of kid's swing chain because it has sharp edges and enough weight that it would be able to scour the inside surfaces of the tank. In order to facilitate getting the chain back out of the tank when the 'shaking' was over, I attached a long piece of nylon rope to the end of the chain and wrapped the other end around the crossbar welded to the underside of the tank. I partially filled the tank with hot soapy water and shook the heck out of it. Ya shudda seen what kept coming out of the petcock hole! I repeated the process until I got only clean water out of the tank. I used the beige-colored cover of one of those big Rubbermaid storage boxes as my work surface so I wouldn't scratch the tank when I set it down. The inverted cover served as a nice catch pan allowing me to see the contents of what came out of the tank. This is an important step in reviving an old metal gas tank. I am considering coating the tank with one of the commercially available tank coatings rated for ethanol protection. I will run an in-line fuel filter for awhile until I am convinced the tank is no longer likely to contaminate the fuel system.

Originally this bike also had a 'stuck' engine which was loosened with a careful mix of chemical rust dissolvers and lubricants accompanied by some gentle nudging of the crankshaft. Then the oil was changed which didn't reveal any ugly evidince. When the bike initially fired up there was some visible gray exhaust smoke but it cleared up quickly once the piston rings and cylinder walls became re acquainted. The engine is now as quiet as a new bike. Prior to starting the engine I checked the valves and found no wear on the cams and valve shims.

The next step in the resurrection of the Yamaha is the brake repair. This bike has dual front discs and a drum rear so only one end of the bike will need attention. One caliper was seized when the bike arrived at my door and remains so as of this writing. The necessary replacement seals for the master cylinder and calipers were sourced from the Old Bike Barn at a fraction of the prices quoted by the on-line Yamaha OEM suppliers. The parts appear to be correct and of satisfactory quality. My remaining wish is that the caliper pistons are re usable. If not, they are a bit expensive. The repair of the brakes is no different than any other bike hence I don't anticipate any unusual problems.

Notice that I have not mentioned anything regarding the electrical system. The reason is simply that everything worked just fine once a fresh battery was installed. This Yamaha has a great feature I wish my 1999 Triumph Thunderbird Sport had, namely a headlight relay that keeps the headlight off until the engine is actually running. That's a smart was to assure that all the available battery power is available for the starter and ignition system. This bike may even have self-canceling turn signals. My 1983 900 Seca had them. Pretty trick stuff for 30 years ago. I was impressed by the condition of the wiring harness in that it had not turned stiff and brittle the way some other old bike's wiring does. And of course, the connectors are modern even by today's standards. These attributes make for a reasonable-cost bike renewal.

The one thing I was worried about was the potential for rusted-out mufflers. NOS replacements would be non-existent for such a limited production bike and the likely hood of encountering rust was ever present. For what ever reason, the muffs on this example were solid and the chrome was (is) even good. The bike was garaged which had to help a lot. Even the paint is good though the clear-coat on the gas tank is crazed. I'm considering wet sanding it with 1000 grit paper and re clearing it or I might just leave it totally original-unrestored. I expect to replace the shocks and fork springs with new Progressive suspension components after I evaluate the finished project. One thing that als surprised me was that the seat cover and its padding were still good after almost 30 years.


As much as we Brit bike loyalists ragged on Japanese bikes of the early 80's, many of them were actually motorcycle engineering masterpieces of their day. And they can even be relatively painless to work on. I particularly like how Yamaha designs things much more so than some of the other makers. This bike is assembled in a logical fashion and everything is easy to get at. But that's what I would expect from a company that makes top quality watercraft, pianos, saxophones and other cool stuff. So, in closing, for a few hundred dollars you can probably buy a 30 year old Japanese rider that's got electronic ignition, shaft drive, double disc brakes, high-wattage alternator, a comfortable seat, good electrics and push button start. I am pretty impressed at what I have encountered with this particular bike. And at my age, I'm liking that package!

I am looking forward to riding this blast from the past to see if it is everything Cycle mag said it was back in its day.

A typical example (a random internet image, not Rich's bike) --Editor

Ride ‘em. Don’t hide ‘em!

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