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12017 miles already?

December 26, 2007

For a while, the folks at Big People saw me regularly and often. When I’d pick up the PX after a service visit, Joe would say, “see you next week for the X,000 mile service?” Yes, I was racking up the miles, for sure.

But with the changing of the season, my inclination to go on lengthy road trips to distant cities decreased a bunch. It took quite a while for the PX’s odometer to finally hit the 12K mark.

The PX is now out of warranty, and as the song goes, money’s too tight to mention. A check of the maintenence schedule in the owner’s manual says at 12,000 miles you need to replace the spark plug and the transmission oil, and check everything else. I can do that.

If you’re really anal (or really bored) you can get a service manual, a set of sockets and a torque wrench (an inch-pound version in this case) and go from one end of the bike to the other, loosening then tightening each bolt to the torque specified in the book.

If I had my own garage with a stand, I’d probably go for it, but since I don’t, I simply have a look at everything. Yes, I’ve mentioned several times that the reason almost every nut and bolt on this bike has a lock washer is because at idle it vibrates. But the PX has had conscientious maintenance throughout its life, and since the bolts appear to be tight and cable adjustments are within spec (and no fluids are leaking from anywhere), I will say if it ain’t broke, don’t fix it.

So, first thing to do is gather your materials. The NGK B7HS or equivalent spark plug, and gear lube. The Haynes manual says to use 80-weight gear oil or 30-weight motor oil. I suppose if you were desperate you could use the stuff that was in your favorite restaurant’s deep-fat fryer, if some biodiesel weenie hasn’t beaten you to it.

Personally, I’d stick with the automotive products. If you decide to go with the motor oil, use a good synthetic. Mobil 1 is readily available, and Pennzoil and Valvoline have full-synth motor oil as well. If you can get it easily, I would recommend Red Line synthetic. I used this stuff in my race car, and while it may be expensive, an engine run on a steady diet of Red Line oil will not only be amazingly clean, it will show little visible evidence of wear.

But I’d suggest going with the gear oil, if for no other reason than it’s formulated for the type of shear encountered by gears meshing with each other. I couldn’t find 80-weight, so I went with the lightest gear oil I could find, which in this case is Valvoline 75W-90. It’s fully synthetic, as are most gear lubricants these days. Also, gear lube comes in bottles with little nozzles on the end; just snip off the tip, poke it into the hole and squeeze.

So, first order of business is to drain the old gear oil. Remember, this is the gear oil. You don’t change the engine oil in a PX 150, because… that’s right! The engine burns it!

Wait, the first order of business is to warm the oil up. You can do that by going for a short ride. Since the PX’s transmission case was covered in ooky schmutz, I went to the self-serve Brown Bear Car Wash on Leary Way and spent two bucks giving the transmission case (and the underside of the bike) a good high-pressure blast. A clean engine/transmission/bike is just more pleasant to work on.

I took the long way home (I’m sure you know that song, right?) to make sure the tranny oil was nice and warm. Time to drain it!

First, remove the filler plug, which is the round thing with a slot in it, at about a 45-degree angle on the outer rear corner of the case. Next, find the drain plug. You’ll see a bolt on the bottom of the transmission case with “OLIO” embossed or stamped into the head. That it’s at the lowest point of the case and points nearly straight down should help you find it. An 11mm socket on a ratchet will do nicely to remove it. Just make sure you have something for the old transmission oil to drain into. Both of these will have a crush washer under the head. DO NOT LOSE THESE! The transmission will leak like a sieve if these washers are missing. (It wouldn’t hurt to pick up a few next time you’re at the scooter shop, since they’re like smoke detector batteries… if you don’t remember the last time you installed a new one, it doesn’t hurt to do so).

Draining the PX’s transmission fluid

The container is one of those Glad sandwich things, with the air-tight lid. But don’t go putting your next tuna salad on rye in it. If you have the kind of garage I dream of, you could certainly clean it out and re-use it next time you change transmission oil, but in this case, I’ll play it safe and toss it.

Once all the old, icky oil has drained out, replace the drain plug, double-checking to make sure the crush washer is in place. As I keep saying, if you strip the threads, you are much worse than screwed (no pun intended), so spin the drain plug back in by hand. Since the threads are soaked in oil, it should spin in very easily with your fingers. Get it finger tight, then snug it with the socket wrench. Snug! Don’t reef on it!!

Next, add transmission oil. The transmission will be full when the oil comes up to the level of the bottom of the filler hole. The spec sheet sez the transmission holds 250 ml, and while you could probably rig up something to measure the exact amount, the book will tell you, keep squeezing unti it drips from the hole. Tip: have your drain receptacle in place, because until you’ve done it enough times to know exactly how much to add, the oil will probably not drip, but gush.

Did you notice the color of the old oil? The new stuff will probably be a clear amber, unless you use Royal Purple (guess what color?) or another such brand. Oil’s job is not only to lubricate, it seals, cools and cleans. The old stuff will be full of dirt and gasoline and 2-stroke oil, because the engine and transmission are a single unit. Change the transmission oil regularly and often, and your bike will be happy!

Finally, replace the filler bolt (snug. SNUG!!) and wipe off the transmission case. If you spilled, dump some clay kitty litter (the 99¢, 20-lb. bag of store brand is great) on the spill, scrunch it around with your foot, then give it awhile to soak up the spill before sweeping it up and disposing of it. Assuming you did the job in a garage with a concrete floor. If you did this in the living room, you’re on your own…

Oh, please, PLEASE don’t be a jerk and dump the old oil down the drain! Get an approved container and pour it into that; when it’s full, find out where you can empty it. Seattle has several household haz-mat dump sites, and lots of other cities probably do, too.

Let the bike sit for a while, then check back to see if there are any dribbles on the floor. If not, pat yourself on the back and get ready to change the spark plug. Regular readers will already know how to do that. Favicon

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2 Comments
  1. December 26, 2007 4:41 pm

    Had to go pick up a couple of things, and I must say the combination of new spark plug and fresh transmission oil makes for a very noticeable improvement in performance. In fact, coming down 3rd Avenue West in 3rd gear, it briefly felt like the wheel might overrun the engine, something it didn’t do previously, and something I’d attribute to fresh, slippery transmission oil…

  2. December 26, 2007 7:16 pm

    Thank you for the nice step-by-by how-to clinic on changing the transmission oil. Way overdue on mine so I better get crackin’! Winter is kinda nice for catching up on scooter maintenance.

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