Ignition timing, woodruff keys

[xwhatsit]

Well an interesting day today.

Ordered air-cleaner and intake manifold rubber O-ring from Econohonda. Air-cleaner has to come from overseas, bugger. Two weeks. Mine looks OK, but it's nice to rule things out.

Started bike, sprayed carb cleaner all around the intake manifold, no difference. No smoke, no change in revs. I'm fairly sure there's no leak. Didn't get to try the burning string trick as I don't have any string lol. But I'm almost completely satisfied there's no leak.

Stripped the carb, and my spare one too. Both looked spotless -- as they should, as I've cleaned them before. I used the spare carb body to rebuild a new carb using the best parts (I had an XR250 carb rebuild kit for gaskets), raised the best looking needle to position 2 (only one notch left before it's richest), put a 125 main in I had bought a while ago (stock is 122).

Making sure I had the slide facing the correct way (cut-out facing backwards, made that mistake before ), put it back together, lots of carb cleaner and WD40 on the outer moving bits.

Put it back together, started well, ran well. Quite pleased. Content to crawl at the slowest speed. It properly *thumps* now at low RPM, will pull from idle. The pumper seems to be working very well, I took special care to sand back some of the rust and corrosion on the shaft, and lube it up nice; there's a great *THWACK* when you snap the throttle open.

(BTW -- how damned cool does it sound without the airbox cover attached? Sounds like a MX thumper, very cool )

It's still not quite right, but with the help of a certain KB member's gas analyser I think I can get it closer.

On the way back from testing it, rode over some glass in the road next to mine. 10 seconds later in the garage, the tyre was flat within 30 seconds. An anonymous KB member took me and the wheel to Mt Eden motorcycles, who put a new tube in and I was home in time to leave for work.

I think I screwed up the brakes taking the wheel out though, as they pull back very far before they do anything useful. I took proper precautions by wedging the calliper apart and certainly didn't touch the lever, but nonetheless there seems to be trouble. Time to order a calliper rebuild kit? Gah I can't afford this.

Thanks guys.

[xwhatsit]

Running reasonably well. Put a fresh plug in yesterday, tested it for today's riding and pulled it out just now. It's much better than before; still more grey than brown/tan, but grey is fine, isn't it?

It's been missing a lot at idle. To the point where it stalled once. Very small throttle openings cause the occasional miss too. I might have a play with the pilot mixture screw. It's fine when you first start up the bike, idles really well, but once you get the engine hotter it will miss and stuff about if you let go of the throttle. From this I will assume it's too rich; as a carb heats up, it gets richer, right? That's why you put the choke on to start it? So it's nice and fine when first started (no choke needed), but once it heats up it's too rich.

[athol57]

OK guys.
Got a tricky one.The advance unit on the different models of CB250RS covered by 3 different part numbers.The question is ,what do the different part numbers mean.These are the part numbers :

30222428315
ADVANCER,SPARK A

30223428315
ADVANCER B SPARK

30224428315
ADVANCER C SPARK

Are these for differnt ignition curves.
The reason I ask is that I hav bought a CB250RS that is marked as a 12.5kw model.
I have drilled out the washer in the exhaust and raised the carb needle to position 4, but the bike still does not go as well as my sons SR250.

Just to keep you informed.
I paid $500 for it and it has only done 600 odd Km's
Not quite mint but near enough.
hope you can help.
geo