Monday, November 14, 2005

Jetting the wee beastie

I got my scoot back in the middle of last week, she's running well & all fixed up from the balls-up job I made of my last wrenching attempt. So what do I do this weekend? Start taking her apart again ;)

Before you say I am just a glutton for punishment, I'll tell you how this got started. The kill switch had gone bad & needed to be replaced. I don't trust part of the electrical system that isn't behaving predictably. While it never died on me while running, sometimes it wouldn't start up without a bunch of jiggling, and it usually wouldn't stop the engine so I have been using the kickstand to kill it when I stop.

The shop would have charged me yet more labor (at $85/hr) to install it while they were doing all that other work. By now I was into them for so much I said, no thank you, just order the new handlebar switch for me & I'll install it myself.

So Saturday morning I drag out my tools, my manual, and the shiny new part, and get to work. It's fairly easy to replace the handlebar switch ... except that you need to remove the throttle cables. And in order to remove the throttle cables, you must first loosen them (a lot) at the "major adjustment" points, which is at the carburetor. And in order to reach THOSE, you must remove the entire airbox assembly & pretty much lay the carburetor bare. After that, installing the switch went easily.

Here I am, looking at the carburetor, thinking, "y'know, it's just a clamp & three hose connections to get this thing off of here." So I decide to remove the carburetor & go ahead and do the jetting.

I am pleased to report it went well. In case you did not know, you can take the carb off the engine, bring it in to the living room, and watch football on TV and drink iced tea while working on it. Cats do not like carburetors and will avoid them ... it's probably the smell. Loosening the tiny little screws that hold the vacuum chamber cover and the float cover without stripping them is a challenge. Also, no matter how well you think you've drained the float bowl, there's still gas in there & you WILL spill it on yourself (or possibly your living room table) eventually. This is why you are never supposed to smoke while working on a carburetor. I am glad I knew this in advance.

I installed the new needle, the new main jet, adjusted the pilot screw, and put everything back together successfully. Put the carb back on the bike (those three hose lines are a b**** to reinstall, Honda crams a lot of stuff in a very small space) and got the throttle cables adjusted right. Put the airbox back on, which is more tedious than complicated, since it breaks into five separate parts. Put the tank on, and a new clamp for the fuel line, the old one is just about shot. Put the seat back on, and I always have a hell of a time getting those screws to thread, it's the one really badly designed thing on the bike. Finally, pop the neck covers & the mirror back on, and she's good to go. It's well past dark by the time I finish all this, so I don't take her for a test ride, but she fires up, idles well, and sounds good when I crack open the throttle in the driveway.

Sunday morning I check the garage floor under her and there are no new leaks, so that's a good sign. Pre-ride check, fire her up, and take her on a nice long shakedown ride.

She runs perfectly! I'm now running a stock size main jet (125) with a Dynojet needle set on the third groove, and the pilot screw out 2-1/2 turns, for those who want details. There's a small but noticable difference in the throttle response from about 1/4 throttle up. She travels well at freeway speeds again (70-75mph for me.) She got up to 80mph without too much effort.

The test ride was one of those where I set off down the road and forgot to turn around for a few hours, so I ended up going 250 miles & getting back after dark again. Damn, it got cold, and I didn't bring my chaps because I didn't think I'd be out that late. ;)