Rubarb

A further couple of points is that since I have got my CT (?) 250 running, it SEEMS that the super low gear is not as low as I remember it. I specifically tested my CL, and found it equated 7500 rpm to 10 mph in super low. I'm now wondering if there is any actual ratio difference between the CL's and the CT's super low gearing. And also, the rear wheel HUB, with it's segmented ring cush drive, is the same as the hub on the CB250RSD, and is superior to the hub on the earlier CB250RSA, which only has 4 rubber bushed fins, and is prone to wear quckly.

I recently bought what I thought to be a CL250S (I had one about 35+ years ago, until some scum stole it). Looking at the engine & frame numbers, it seems that it may be the very similar CT250s. Anyway, the balancer arrangement (as mentioned by Janvixen) differs in that the CB models have chain drive from the crankshaft to a front balancer shaft with 1 bobweight, and also to another bobweight which runs on the gearbox output shaft, but the CL/CT models have gear drive from the crankshaft to the front balancer shaft only, which has 2 bobweights on it. This leaves a space on the gearbox output shaft, onto which the super low gear is fitted. Also, the overall gearing is lower on the CL & CT models than what it is on the CB models, plus the CB has higher compression and a higher state of tune than the ÇL/CT, and a different carburettor. And the XL 250 engine is not quite the same, it has smaller, more restricted exhaust passageways, and is not machined on the right side of the cylinder head to take a tachometer drive gearbox. Hope this helps. M.S.

I would certainly check the float level, and also the action of the float valve, and the condition of its seat. M.S.

For what its worth, one problem that can occur with some 2 strokes, particularly older types, is that if the carburettor is flooding (even slightly), then when the engine is stopped, fuel can drain into the crankcase. Then (after standing for a while) when the engine is started, this causes a very rich mixture, and because it is liquid fuel (not atomised by the carburettor), it may take a while for all of it to be cleared out of the crankcase, thus causing the engine to over-rev for a while on start up. Of course, once this exess fuel is used up, the engine runs normally, until the next time it's started after standing for a while. This is why many older 2 strokes had a crankcase drain plug. There may be another reason for your engine's misbehaviour, but I hope this helps. M.S.

For any bike which has drum brakes, there is the option of removing the barrel nipples and adjuster nuts where the cables connect onto the brake pull arms.