Bill Hoddinott VA (Enthusiast) View all posts in this topic  
Sun Jul 17, 2005 3:26 pm
100,000 Mile Road Test of a 1988 Kawasaki 250 Ninja - Part Six        

I meant to mention in the last part that I noticed, when I replaced the front brake pads with the original oem, that the inner pad was worn more than the outer. As Kaw points out in the Service Manual, this is undoubtedly due to the front caliper piston and seals are a bit dirty and corroded, so not returning to their rest positions quite as freely as they should. The practical result is that the inner pad rubs more on the disc than the outer, hence wears more. Ideally, I should have taken the time to take the caliper piston out, clean everything out, and re-install it with a new seal. But, since it was still functional and did not display symptoms of significant drag when spinning the wheel and operating the front brake, I let it ride. But this will undoubtedly result in uneven wear of the front pads, to the detriment of the inner one. However, since I seem to be so easy on equipment in general, it will probably take many, many miles before the inner pad is worn much.

Front forks. When I got the bike, I noted at once that the exposed fork stantions were going to be at hazard of getting chipped by flying stones on the road, and that this was bound to be harmful to the life of the fork seals. So I went to NAPA and got a suitable piece of large OD straight radiator hose. I cut two pieces of this and slit them so that I could secure them to the tops of the fork sliders with hose clamps, to form shrouds for the chromed fork tubes(stantions). These were made to a length that would not interfere with the lower fork yoke at full fork compression, and care was taken that the shrouds could not interfere with the fairing or any other part during normal turning or any other operation. If they did, that could cause you to fall.

Okay, at about 45K miles the fork seals did begin to leak, so I got some fresh Kaw seals and the dust cover/scrapers that go atop them. And after fashioning some simple tools to enable installing the new seals with no damage, put them in place in accordance with the instructions in the Service Manual.

During the process I checked over and polished the chromed tubes to remove any little nicks they had on them. Now at 100,000 miles plus, the replacement seals have not yet started to leak.

I note that I could not find any 10w-20 oil for the forks, which Kaw specifies, so I used 5W-30, and this was just a tad too stiff in damping, but acceptable. Kaw's oil is better. Front forks are very sensitive to having just the right weight of dampening oil in them. Too light is too bouncy, not enough damping, and too heavy gives a stiffer fork action than you want. The ideal is when the fork seems to 'soak up' the bumps, and this is an important consideration.

At 100,000 miles I checked the front steering head adjustment, which has never been touched from the factory, and found that the bearing was still perfect. NO play, and smooth-turning from lock to lock. Had I ever had a habit of doing 'wheelies', this would NOT have been the case, of course, because that practice is about the same as hitting your steering head bearing with a sledge hammer.

Kaw instructs riders to take their rear fork bearing apart and service it, but I never did, and checking it with the wheel off the deck shows no play in it. It apparently is as good as new, and the same applies to the complete rear suspension and linkage. Never any leak, never any deterioration in action, never any squeak, never any change in ride height. And no attention has ever been given to any part of the rear suspension.

I hasten to add that I try to avoid getting caught in the rain, and use the bike for sport only, not commuting. It has been out in the rain only maybe a dozen times in all these years, when I got fooled by the weather forecast. Nowadays, the National Weather Service has a good Internet forecast service, for our city, town and molehill in America.

This bike has always been kept indoors, and obviously that makes a lot of difference in preservation of the whole bike. Not to mention the theft considerations. Wes has pointed out numerous times that he's had rust attacking his rear fork bearing due to rain-riding.

But as noted early in the report, I do what's necessary and skip the rest.

I might mention that the original clutch cable, levers, instruments and gauges are all in place and working fine. At about 50K miles the speedo needle started jumping a little bit, which is a symptom of a dryish cable. So I extracted it carefully(using NO force) from the front fork gearbox end. I then gave it a careful coating of molygrease and eased it back into place with great care, until it re-entered the speedo head. I took care not to put too much of the grease near the speedo head end, because it is known that if excessive grease gets into the speedo head it can mess it up fatally. Anyway, since this treatment the speedo has worked perfectly ever since. I never touched the speedo drive gearbox on the LH side of the front fork; whatever Kaw does that by way of assembly and lubrication has been a great success.

Electrical system. I've never yet had the slightest trouble with the original electrical system, save only the original flasher, which quit at about 50K miles. Kaw wanted $29 for the genuine replacement, so I opted for a $2 item from an autoparts store, which has worked perfectly ever since.

When I changed the '88 engine for the '01, I was extremely careful with the handling and routing of the electrical cables that come out of the LH side of the engine and convey the ignition timing and charging power. I cleaned the fittings for them on the bike wiring and secured all carefully. These are critically important parts. I've had no trouble with any of it, about the seemingly miraculous ignition system and its advancer, all electronic apparently. I know nothing about it and don't need to. It just works and keeps on working. Once a year or so I top up the(old style Yuasa) battery and when I do, I check the charging system. When the engine runs, the voltmeter just shows a reading around 14v, which is ideal and exactly what the battery needs to keep in good condition.

Batteries have lasted about three years. An engine that starts instantly(as it should) is easy on the battery. I prefer the old-style Yuasa battery to the new gel type. It pays to keep a fresh Yuasa on hand so that if your old one shows any symptoms of weakness, you can just change it. No point in fooling with any battery that exhibits deterioration. I've never known one to make a 'comeback'.

When removing and replacing batteries, one needs to take great care to get the vent tube into the clever receptacle provided for it, which conveys the charging vapors down under the bike. This vapor will other wise cause severe rust and corrosion if you let it go where it doesn't belong.

I have observed that the speed of your turn signal flasher serves as a simple sort of voltmeter. Once or twice when I got careless and let the electrolyte drop too much in my battery, the battery got into distress and the voltage control system upped the value to about 15. The higher voltage was displayed in the speeded-up rate of the flasher, and this quickly called my attention to the fact that something was wrong. But the higher temporary system voltage did not burn out any bulbs or cause any other known harm.

I had to change the headlight bulb three or four times over the 100K mileage, and the taillight bulb about the same. I learned early on that it pays to get the HD taillight bulbs that Dennis Kirk sells(in the wattage Kaw prescribes) because they hold up far better under the vibration of a motorcycle than will the common bulbs you get at an autoparts store. The tailight and brakelight, obviously, are important safety items. You want the maximum reliability with them, and one should check their function frequently.

I might mention that at 80410 miles I had some symptoms of clutch slip at full power in the upper gears, so replaced the clutch friction plates and clutch springs only. In checking the old parts against the Manual specs, I did not see that they measured out of spec. But regardless, these replacements corrected the problem. I never had the slightest trouble with the gearbox of the '88 engine. The gear selector always worked perfectly, which is just as well because any repairs mean a complete teardown of the engine. Pressing the gear lever to go from gear to gear is the key. Stomping it is bound to lead to trouble sooner or later, and a big repair bill or a big job if you can do it yourself. At about 70K miles the gear lever assembly did get worn and sloppy, so I sourced a good used one off eBay for cheap, and this is still in place now. Roland reversed the operation of the pedal to get down for up, like the old Brit standard, even though on the 'wrong' side of the bike. This can easily be done, and I follow suit.

End of Part Six.

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