1958 C15 - Non Starter

[Mutley 99]

Hi All, newbie here 

I recently did a mad impulse purchase of a 1958 BSA C15 - A non runner

Got it home, fuel tank full of rust - All cleaned out.

Spark plug removed WD40 in the cylinder, engine turns over nice and free. Feels like its got reasonable compression (I will do a proper check later)

Carburettor removed cleaned etc and refitted with inline fuel filter. There is no choke on the Amal carb, like some I have seen.

New 6v battery, New fresh fuel, Spark plug sparking.

But the old gal does not want to start 

Removed plug wet with fuel, with it not running for what I believe a few years, could it just be being awkward ?

What other areas could I check?

[idie]

Have you got a spark? Check the points if not been used points may need cleaning
 Check connections to coil if no spark is coil good?

[limeyrob]

Check the timing and condenser.  It's possible it was parked up because the PO couldn't get it to start so go over everything one more time and assume there may be a simple fault that's been missed.

[Jazzman]

Plug leads can fail as well as caps.
If you have a spark, pour a little bit of petrol down the bore and kick it over, if it fires and dies it could be the carb.

Good luck,
Mike.
   

[rhyatt]

unscrew the plug cap from the HT lead and lay/wedge the end of the lead onto or between a couple of fins.
give it a kick with plug out -- good blue crack ?? or not??
could be just a dodgy HT cap , should be max 5K ohms or pushing it 10K ohms

[V500]

All the above posts suggest HT faults, but the OP says the plug is sparking. Unless the spark is "blowing out" under compression (unlikely) then it would appear that the fault lies elsewhere.
I would suggest that the pilot jet circuit would be next to check and verify (as the bike hasn't run for years) and a simple check of the timing wouldn't hurt either.

[Mutley 99]

Hi All,

Many thanks for the suggestions etc.

I have got a brand new NGK plug with a good spark, the points did look a little dirty, they have been cleaned and I did notice when in the closed position if I manually open the points there is a tiny spark there also.

I have checked compression and it is about 145 psi, and when kicking the engine over it certainly feels like its got good compression, once or twice it has kicked back with some force.

How do I check the timing for the points? And should I also check the engine timing, as in the crankshaft to the valves?

Carburettor has been stripped cleaned and rebuilt, it was full of dried up fuel, but now all is clean.

Thanks again for all the help, it is very valuable.

[rhyatt]

The points should open about 1/16" before tdc on the compression stroke.
That's near enough to get it running.

After you've kicked it a few times and not starting , whip the plug out , is it wet or dry ?

[limeyrob]

Valve timing is almost certain to be right.  Don't undo anything on the ignition timing, its most likely right, but check it to make sure.
Have you tried a new condenser on the points?  They fail with age and cause a weak spark.  I recently had a problem of non-starting and it turned out to be the new NGK plug, it was a fake. Try another brand of plug too.

[rhyatt]

An old champion N5 or similar thread length should do fine.
Sadly as mentioned there are fake NGK around.
Pull a fine file across the plug electrodes to give you a bright metal area , that'll spark most engines

[DAVE BRADY]

Hi,

It may be worth checking the carb again. The very small air/fuel drillings can be quite difficult to get clean if the cab has sat for while with remnants of evaporated fuel.
Use some carb cleaner in the holes and see if it comes out the other end.  Use an air line to get a bit of pressure in there.

Dave.

[Mutley 99]

Hi all
Quick up date. Removed the little cover on the end of the rocker housing to find the inlet pushrod not connected to the inlet rocker.
Removed rocker housing, cylinder head and barrel
OMG I think a previous owner or 2 must have made a bulk buy of black RTV sealant and applied large amounts to every surface and gasket twice over!!
Tried to attach photos but not sure how to fo this.
I have ordered full engine gasket and pushrod tube this also had a dent in one end filled with black RTV sealant. Some people should never be allowed to touch motorcycles or any other mechanical device

[limeyrob]

I feel your frustration. I've learned the hard way to assume nothing when it comes to previous owners work!  A Monobloc with a concentric needle, an "rebuilt" A10 engine with 20 thou end-float and no shims, a Matchless with a rebuilt engine with assembly lube connected to an oil tank full of debris

[rhyatt]

It's useful prior to reassembling to identify the exhaust and inlet cam followers
Exhaust innermost and mark with paint and then mark tof it's pushrod with paint.
This facilitates reassembly looking through the little window locating pushrods into rockers