A quick quickie

Aaaah, that's the stuff. The stars have aligned themselves advantageously, and the bike feels the strongest it's been yet. To recap, we're currently on:

Halfords 10W 40 semi synthetic oil.
Activ-8 friction reducer.
K&N cone air filter
95 main jet (down from 100)
Needle in centre position (down from 2 up and 1 up)
Idle screw about 2 turns out
DPR8EA-9 plug with the earth electrode cut back.
97 octane fuel
Stock CDI
Aftermarket coil.

There we go. I did file the electrode back a little more, and it doesn't seem to have harmed it (yet). Now the bike is happy all the way through the rev range, pulls away strong, revs smoothly right up to 10,500 and the plug is staying clean. It's perhaps a little too clean, and I may go back to a 100 jet or raise the needle, but for my current short commutes it's probably good enough.

Today's purchase was 5 Metrics of Halford's 5W 40 fully synthetic oil. I had a look at Castrol Power 1 GPS 4T 10W-40, but it's 4 Metrics for the same price and only semi-synthetic. I want to give filthy Nature a body-swerve on the next oil change to see if I can reduce the clutch drag a little.

I'm modest to a fault
I feel that it's my duty to mention again how much positive attention this cheap little hack gets from other bikers. A Honda CB750 pilot - a proper classic bike, so obviously a discerning chap - collared me at the shops to enquire about it. Apparently it's a "really tidy little bike", a epithet with which I can only concur.

Poor bike. Poor, poor bike. When will the madness end?

More entries in the Catalogue of Foot Shooting.

Bondage
The rear of the leather panniers on the bike would rub against the wheel given their druthers, so I made up an aluminium bracket to hold them away from it. It's a W shape, attached to what were the rear seat/luggage rack mounting points, with the centre of the W being an arch over the wheel. When I first made it, the arch was right up under the rear mudguard, giving plenty of clearance. However, after putting the custom seat on, the panniers are now slung directly on the rear mudguard, and are sitting lower down (which is generally a Good Thing). I had to extend the left and right corners of the W down, which meant "stealing" some length from the supporting arch. I thought it was still comfortably high enough...

You can probably guess the rest. Spotting a big ditch in the road, I stood up to smooth the ride. With the rear unloaded, the wheel jumped up, caught the centre of the aluminium bracket, and dragged it around - I mean, it actually pulled it into a U shape, until the bracket ended up wrapped around the front of the wheel.

Screeeeech, went the wheel as it locked up hard. I'm happy to report that I held it up, even got the clutch in and kept the engine running.

There was a little cosmetic damage to the ring over the sprocket, but the bike seems to have survived the incident just fine. I've kept and sorted the bracket - the panniers need something to hold them apart - but now the arch is running behind the wheel rather than over it. All seems OK so far, but it's something else to keep an eye on though.

Smut
The bike has been bogging down at idle, and every time I've pulled the plug (DPR9EIX-9) it's been sooted up badly. I changed the 100 jet (stock was 90) down to a 95, and leaned the idle out, but to no avail. Suspecting that the D*9* was running too cool (it transfers heat to the engine faster than a D*8*), I rustled up a spare non Iridium plug that I happened to have lying around, a DPR8EA-9. Something I've been meaning to try on a plug is cutting the earth electrode back so that the spark jumps diagonally. The idea is that this exposes the spark more fully to the fuel-air mixture and allows better combustion, rather than having to flow around the electrode. The effect - if any - is probably minimal, but this is a Project Bike, so here goes:



It's rather conservative; there's still some overlap of the electrodes. I think I'll trim it back a little more - you know, until it stops working. Note that the gap between the terminals should still be 0.6 - 0.7mm, just diagonally rather than flat.

Verdict: well, it works. I won't say that it works any better, but the bike started and ran just fine up to 10,000rpm, so if you fancy a fiddle, I'd say go for it. It'll give you something to bore the missus with, if nothing else. Update: my missus just read this entry, so Mission Accomplished.

Slipped disc
After my ride to test the trimmed plug, I pulled it and it was already sooty as a chimney sweep's nostril. Something's not right here, thinks I. I'd already moved the needle back from raised one slot to the centre slot, but pulled the slide to lower it again.

Ah hah! When I disassembled it, I found that the spring clip that should sit on top of the needle circlip and hold it down had found its way underneath the circlip - in other words, the needle was sitting way too high, and there was actually nothing holding it down except for the wafer-thin grasp of gravity. That explains the sooting, although the mystery of why I can't leave well enough alone remains unsolved.

This spring clip is really fiddly to fit, but I took my time with it and got it solidly in place, with the needle left in its stock centre position. Tomorrow will tell whether I've managed to "improve" the bike all the way back to its out-of-the-box performance. It could happen!

How low can you go?

How's that looking? Speak up? "Super Pimp", you say? Well, if you insist.

That's a custom seat made from a piece of spare floorboard, some upholstery foam, and cheap (but surprisingly nice) brown vinyl, courtesy of eBay again. It slots into the retaining groove at the front, and has two bolts and wing nuts holding it down at the back. It'll need a bit of re-jigging, but is basically sound, if not quite as supportive as the original. I may put another layer of foam in, as it's only medium density.

In other news, the bike was bogging down at idle and low revs. Pulling the plug after a period of idle revealed it to be blacker than a parking warden's heart, which I've attempted to sort by leaning out the idle mixture substantially. I'd forgotten that I'd been creeping it richer and richer during the Lang Way Roond to try and keep the engine cool (through evaporative cooling) but had taken a good thing too far. Now I'm running it really lean for a bit to see if I can find a happy medium. I suspect that I should be using the choke for a minute or so in the morning, rather than running it so rich that it doesn't need any choke while cold. Further bulletins as events warrant.

And in a further bout of en-tweakening, I've replaced the aftermarket "POSH" branded CDI with the stock one. The bike is very slightly less eager between 5000-7000 rpm, but runs smoother above 8500rpm, where the POSH was missing, allowing a higher push in 4th gear before the shift to 5th. I think the POSH was staying too advanced at high rpm, lowering the top speed. Xian now do a "Kamizake" CDI which they've developed themselves with testing from Forchetto from the Chinese Bike Forum. I may give that a try to see if it gives the best of both worlds.