New Ride: 1981 Yamaha XJ650 Maxim

A deal too good to pass up... So I didn't. This gem was a solid little garage find from one of our fine serviceman at Ft. Bragg. (Thank God for him and all the other men and women defending and serving our country.) He wanted to sell it quickly and inexpensively because he was deploying and it had already been sitting for over two years. Of course, the bike had the normal problems from sitting, plus a few more. Gummed carbs, dead battery, non-working brakes, and a thick protective layer of dust. Besides slightly tweaked original handlebars, the bike was straight and cosmetically fine. The paint was hazed a bit and the chrome needed polishing, but all is to be expected. On a difficulty scale, from mothballed to road-ready, the middle-sized XJ looked to be about a 5 on a scale of 1 to 10.
This was my first 650 4 cyl. from Yamaha of this era. I was curious how it would perform. The 1981 Yamaha XJ550 Seca I had was impressively quick and spirited. I'm not a big fan of the "psuedo-cruisers" that the big 4 started producing in the early-eighties style wise, but most of the time they still went down the road well.
More to come...

A Rant Against "Customizing" Your Motorcycle.

Well, right off the bat, I want to warn my loyal readers that this post may offend some of you... Of course, this isn't my intent, but enough is enough, this needs to be said.

DO NOT CUSTOMIZE YOUR JAPANESE OR EUROPEAN MOTORCYCLE! In almost every instance, "customization" is more akin to "bastardization" and should be considered a crime against humanity.

It doesn't matter whether the motorcycle is old or new, a cruiser, standard, or sportbike. The compulsion that many owners feel to "improve" their bikes needs to be resisted. A 15" extended swing-arm on a lowered Hayabusa not only looks foolish, but it destroys the handling and all but renders the machine useless. Removing the shocks and welding in "struts" on that 1971 CB750 does not make it any more cool. Either does removing the fenders and lighting. And your bike is certainly not cooler if, shocker here, you give it a flat-black rattle-can paint job accomplished without any masking tape. You all have seen the Craigslist ads advertising "custom paint" or "one-of-a-kind bobber/chopper", etc. You know, the ones that are being sold for the same price as an original unmolested bike. Every time I see an advertisement with the word "custom" in the description I immediately get sick to my stomach. Especially with older/collectible bikes. It really hurts me deep down inside.

Okay, okay... I'm being a bit ridiculous. There are some tastefully and well-done customized bikes out there. Some even that I would love to call my own. The reality of it is though, more often than not, the "customizer" lacks the skills, tools, and/or knowledge to do anything more than destroy the motorcycle. And even when the "builder" is able to pull off what he's trying to do, beauty really is in the eye of the beholder.

IF YOU CANNOT RESIST THE URGE TO "MODIFY" YOUR CLASSIC MOTORCYCLE, PLEASE, PLEASE, PLEASE KEEP READING...

1) First of all, I'd ask you one more time to reconsider. Try to appreciate the character of the motorcycle as it was intended to be. An old Honda CB, Yamaha XS, or Triumph Twin in basically unmolested yet functional condition is pretty rare these days already. If you come across a nice one, keep please consider leaving it that way. They are MUCH more likely to appreciate in value than a modified bike as well. In fact, if it's really nice, you probably could finance your entire project by selling it and buying a rougher one.

2) If you must mess with it, try to do it in a way that it is reversible. Many things, like handlebars, seats, racks, exhausts, electronic ignitions, etc., are bolt on items and can be added or swapped without otherwise damaging the bike. Put the removed parts in a box in storage, or sell them to somebody looking to breath new life into their bike, and at least nothing is lost. If you're painting body work or gas tanks, even if you think it's in lousy shape, PLEASE check to see what similar ones are going for on Ebay type sites. Some years, styles, etc., in original paint, even if only in fair condition are worth a mint and VERY desirable to some. Consider selling your parts and getting ones in worse shape if you're going to be repainting them anyway.

3) If you're going to be cutting or welding, you're probably not still reading this anyway. If you are, and you're set on it, make sure what you're doing is SAFE and STRAIGHT. I've seen some dangerous looking chopped/bobbed bikes being ridden by young kids with their first bike they thought was cool or got for a "deal". Remember, you may find somebody foolish enough to part with their money for your bike down the road. Please be responsible about it.

4) Wow, I can't believe you're still reading this... Last thing: If you do decide to paint ANYTHING on your bike, either take the part off, or spend the extra 10 minutes masking it off properly. Nothing looks worse than a crappy paint job, and very few things are more difficult to "fix" than over-spray where it shouldn't be.

Harbor Freight lights the way.

I needed a timing light... And since I don't know anybody with one to loan, I had to bite the bullet and buy one that I'll probably only ever use once every 2 years.

Where do you go for a "single-use" or disposable tool? Harbor-Freight Tools my friends. Say what you want to about the quality of their Chinese-made plastic "hurry up and use it before it falls apart" tools, the price is right if you only plan on needing it once. I'm pretty sure I only dropped $7.99 on the "Chicago Electric" timing light, and while looks like it was appropriately priced, it did the job asked of it.

The procedure for checking the timing according to the Haynes workshop manual from my "library" said to first check the timing at idle 800-1000rpm, and then the advance at 4000rpm. If you recall, I had rotated the backing plate of the Dyna ignition pulse coils into the fully retarded position in order to help cure the spark-knocking.

So I've got the light hooked up properly and I'm about ready to summons the big KZ to life. Man... if this thing is correctly timed, it's going to really suck. Do I keep retarding the timing even at the expense of power? Well, I'd have to do something... It's not rideable the way it is. The plugs, appear to indicate a rich condition if anything... A compression test showed between 115 and 123psi on all four cylinders which really doesn't seem that high. Are the combustion chambers really so poorly designed that 120psi is too much? I really don't want to tear this engine down... ENOUGH ALREADY, just check the timing!

What did I find? The timing was still WAY TOO far advanced. I would guestimate about 7 degrees too far advanced even with the backing plate rotated all the way retarded! Wow... At first I thought the plate may have been installed backwards and because of the positioning of the pulse coils relative to the rotor it would be too far advanced if installed improperly. After spending more than a half hour messing with the ultra-tiny nuts and bolts used to fasten the coils to the backing plate, I flipped the mounting plate over. Folks, I should do a little more measuring next time... My assumption that the backing plate was backwards was such a good explanation to me that I just went ahead and did it without really looking or measuring to see if was the case. ANYWAY, I was wrong. The plate wasn't even close when flipped around.

Since everything else was fixed in position (rotor is fixed relative to the crankshaft) the next thing was to enlarge the adjustment slots to allow me to further retard the timing. It turned out to be a 45 minute job with an old-fashioned chainsaw round-file, but a simple one. After a few tries, I removed enough material to set the timing properly.

The fix was easy enough, but why did I have to do it in the first place? Was it just an incorrectly machined backing plate from Dyna? A plate from a different motorcycle that happened to fit properly otherwise? I'm not really sure, and at this point it doesn't really matter.

BUT, it does raise some red flags about the history of the bike. Although, according to the previous owner, it wasn't his "trusted friend and shop" that installed the electronic ignition, the bike had over $5k in receipts for engine work in the previous 5 years. Including two times where the top-end was removed and once for crank bearings. Did the shop never check the timing? And further, how could any actual mechanic ride this bike without immediately noticing and at least indicating to the owner that something was awry? Especially, since the shop seemed to be quite willing to dive deep into the motor, a timing issue shouldn't have been outside their ability. I don't think it's possible... Something about the story doesn't add up. When I consider that the 29mm smoothbore carbs disappeared after being removed when the shop claimed they were "worn out", I wonder how much of the engine work was actually done. Was any of it done? Boy, I really wish I could have gotten the name of that shop...

KZ1000: More disappointment.

So as we left off last time, I was complaining about the bike feeling too flat on top end. Essentially, what happened was the previous owner's shop switched a set of sweet Mikuni Smoothbore 29mm carbs out for a set of stock 26mm round slides. They also transferred the main jets: 120s... All else equal, a larger bore carb will require larger main jets to flow the same amount of fuel. So when the "shop" transferred the carbs over, the 120 mains were likely all they had in stock and was "convenient". Insert rant about how too often people get taken advantage of because of their lack of familiarity with things... I'd love to have a few choice words with the turkeys who were "helping" out the previous owner as a "friend." ANYWAY... This bike, with APE pod filters, 117.5 mains and 20 pilots ended up being pretty darn close according to the SOTP (Seat of the pants) dyno.

But this SOTP dyno run came after much fuss with the ignition timing... The KZ snapped crackeled and popped even on 93 octane fuel far worse than any bike I'd riddent to date. As previously mentioned, the KZ had a Dyna electronic ignition installed on it eliminating the points system. The Dyna set up was pretty straight foward and simple looking, with a slotted backing plate to adjust the static timing just like the original equipment points set up. Upon intial inspection, it was adjusted right in the middle of the adjustment range. I didn't have a timing light at the time so I just eyeballed it and retarded static timing a few degrees. Still spark knocking. A few more degrees... No improvement... All the way to "fully retarded"? There may have been some slight amount of improvement, but it still wasn't cutting the mustard. I double checked the mechanical advance unit to make sure that it was working properly and wasn't stuck in the fully advanced position. Everything looked correct.

Is this is just the way this thing is going to behave with the big-bore/high compression pistons? What's the point of carrying around the weight of a liter bike if you can't even use the mid-range punch? The KZ650 was vastly superior to it's big brother when motoring down the road because of the nagging pre-ignition problems. I was disgusted with the Big KZ.

Time to buy a timing light...