C-15, it runs!

[AndyM]

Hello all.
I bought a C-15 a couple of months ago and although it ran when the seller started it it leaked fuel from the carb.
It's in reasonable condition and has been converted to 12v. First job was to strip the Amal 375  to find the flange distorted and the slide scored, the jets were not the specified ones either. Fortunately Burlen Fuel Systems are only 10 miles away and when I showed them the parts their advise was to replace it with a new standard carb.
The fuel tank had a lot of fine rust in it and I have had white vinegar in it for a week before flushing out but it's still not that clean.
Today the new carb was fitted with new fuel line and an in-line filter, I had bought a replacement slide for the fuel tap, new N4C spark plug to replace the wrong plug fitted, new battery roughly installed . Fuel tank and seat were re-fitted so I thought I would give it a kick over just in case something might happen. It started second kick!
It revved guite high though so I turned it off after 30 seconds.
I had  fitted a new throttle cable before installing the carb and that hasn't been adjusted yet so that might not be allowing the carb slide to fully close but to tomorrow I'll adjust the stop screw first as I set that and the air screw as they were set on the old carb.
Great day though!
The bike is blue but the tank looks to have been re- chromed and then re-painted as the paint chips of easily and the brackets for the knee pads have chromed mangled scews!
The bike was registered in 1964 but the frame number, C15 25322 and engine number, C15 26327, seem to point to a 1961 model. The engine is the distributer type.
I have read plenty of information and good ideas on this forum and I am sure I will be back with more question when I give the engine a check later this year.
Regards.

[johnan]

Another happy C15 owner!

Congratulations on getting one that seems to be easy to start, did you just tickle the float until fuel appeared, or does your machine have the usually redundant enrichment/ choke lever fitted and if so did you use it?

I am still trying to find a fool proof method of getting my C15 to start without going beyond 3 kicks..it is too easy to over tickle it and end up flooding it.

[AdrianS]

Rust in the tank is a common problem.
I spent ages cleaning my tank out - shaking a bag of nuts and bolts; white wine vinegar,cheap Diet Coke, and finally some spirits of salts ( hydrochloride acid).
Now I add a splash of 2 stroke oil to a tank full of petrol to keep it very lightly oiled inside.

[DAVIDMORGAN]

Hi Andy,

I had similar problems with my C15. I had to fit a new carburettor. the new carb was from Amal, however for some reason there was not enough adjustment on the throttle cable to ensure the slide went fully down to the bottom, I had in the end to remove a few milometers from the outer cable in order to get the tickover right.

[chaz]

regarding the rust in fuel tanks. a timely reinder to new members to search ethanol in fuel, one of many write ups worth reading,   https://burtonbikebits.net/ethanol-in-fuels/

[AndyM]

Thanks for all your comments. Johann, there is no choke lever, just the tickler.
Yesterday's good news may  have been a bit premature as  the engine didn't want to start today, in fact on using the kick start a training noise was heard and the kick start seemed to slip. The engine would turn but on a few kicks it felt as if something had jammed. I' m unsure about how the clutch disconnects the gearbox from the engine, on pulling the clutch lever in the kick start didn't t seem to connect to the engine.
David, the new throttle cable I fitted does seem right with no adjustment available, I'll put the old one back on to see it it makes any difference as it has an adjuster along it.

[johnan]

Andy, re. the kick start on an early C15.
Apart from the fact that the kick start pinion "flat", where the cotter pin wedges against when fitted into the kickstart lever, on mine was badly damaged and kept allowing the lever to come loose...occasionally when kicking it over it would "miss" and not turn the engine over.
On these engines a small pawl engages with an internal tooth inside the first gear on the main shaft in the gearbox, and these small pawls get worn/damaged by heavy footed owners who just keep kicking the engine over when it won't start, rather than trying to find the cause. Once the pawl is damaged it will not always engage cleanly and it can miss the internal ratchet tooth, or sometimes seem to catch it an awkward angle and seem to jam it.
The solution is to change the pawl which are available from Draganfly, at least that is where I got mine, but a bit of work is involved which I put off for a long time but actually it was quite straight forward.
You take off the outer right hand cover, drain the gearbox oil ( if there is any in it!) and then take off the inner right hand gearbox cover which gives you access to the kickstart pinion and pawl.
Best to read up on that first as there are a few things to watch out for in the process of removing the covers and if you don't already have them the Rupert Ratio books are the best reference manuals out there.
These pawls wore so badly initially, BSA produced a service bulletin for mechanics explaining how to do the job, which you may be able to find on line somewhere.
I think it is normal for the engine not to turn over when kicking it, if the clutch lever is operated.

[JulianS]

This is the factory service bulletin mentioned by johnan.

[johnan]

Thanks for enclosing the copy of the bulletin Julian, I tried to find mine but failed!

Andy, if or when you do the job, as I said there are a few things to look out for and one that I wasn't made fully aware of was the need to keep ALL the spindles that protrude through the inner cover in place as you withdraw the cover. You need to tap them lightly with a soft hammer regularly and often as you move the cover outwards.
My problem was I kept an eye on keeping the kickstart shaft and gearchange spindle in place but forgot all about the end of the camshaft which is away on its own towards the front of the engine. As the cover was removed the cam spindle, being a tight fit, came with it and so did the camshaft drive gear of course which is one with the spindle..so my valve timing was lost and I had to reset it. A pain in the neck, not a big issue but to be avoided if you can.
Another thing, I found the replacement pawls I bought, only needed one but got a couple of spares as they were so cheap, were quite a tight fit in the recess into which they fit in the KS pinion and I had to dress them a little to allow free movement, which is necessary. May just have been the ones I received.

[AndyM]

Thanks Johan
I have a copy of Rupert Ratio books and them and an old oily copy of the Haynes manual.
The kick start is loose on the shaft and tightening the cotter pin doesn't improve the fit.
Main task is to get the engine running correctly and then to look at the other bits later.
Julian, the service notes will be very useful, thank you.

[johnan]

I had to replace the kickstart pinion because the cotter recess in the old one was damaged and the lever always became loose after just a couple of kicks. I changed the pawl at the same time.