Wasted day ..

[john.nash]

A little while ago I swapped alot of my VB stuff for a 500 twin port head and barrel (thanks Will!). I redid the valves and had the barrel rebored ready.

The single port bike ain't been run for maybe a few months, until I hauled it up onto the ramp, maybe 6/8 weeks ago for the swap, but had been running fine.
I got half way through and then was stopped waiting for bits ... (as i also decided to finally sort out the oil system, the stupidly tight fuel tap and also fully replace the breather for a reed one etc etc)

....anyway the parts turn up yesterday. A flurry of a very late activity night last night and this morning, saw me kicking it. Nada
Nothing. Good compression, spark and a carb full of fuel. Nada. Checked everything thrice. nada.

I had a massive moment of doubt over whether I'd got the cam right. Took it all down and fine.
Reset the timing. Reset the clearances again (though they are ok).
Cleaned through the carburettor.

Nope.
advanced. retarded. Nothing
The plug gets a little wet. Changed plug. Twice. Nada.

I have 3 month old fuel in there but that isn't usually a problem.



I so wanted to take this bike and follow Len, on Thursday, as it's one he helped me with .....

[Steven.Carter]

Got to be the magneto John, maybe the spark disappears under compression. `I have some 1 year old fuel in my KH and that goes.

[brenton.roy]

Hi John,
First starts can be really difficult. The extra friction is a pain - and so is your worn out leg!
Stephen makes a good point.
Can you get the ether "aerostart" stuff I wrote about earlier. It will probably work with a weak spark.
To be on the safe side, new petrol wood be good.
The last bike I had do this (recently) turned out to have a fine film of crap on the points. Enough for a spark, but not enough to start.
Good luck John.

I lost the tail light lens / door off the '27 - along a well travelled route yesterday.
Off to see if I can see if I can find the crumpled remains..

[john.nash]

I had the magneto re-done 18 months back ?;the spark looks big and blue.
I checked and it was last out in very early October ... I drained all the fuel out at that point ... so it's been sat in a can since.

I'll check for muck on the points; good idea.

It will kick you back with the typical huffy noise, but just will not bloody go.

once upon a time I had a BMW R100/7.
Upon the severn bridge (long exposed suspension bridge), one carb float chamber fell off.
I realised something was wrong but kept going the mile or so to avoid stopping on the bridge (as it was blowing a gale and raining)
I walked back the mile or so, to find it squashed flat and then walked the mile or so back to call for a recovery.

[GuyH]

This is a long shot but....

A few months ago a mate of mine had the same problem with a 1930s Triumph XO 150 he'd freshly restored. I took over the carb from my XO to try as he couldn't get the bike to start although occasionally it would fire once and stop. We put my carb on and it started. Turns out his jets were so worn that they put through too much fuel for the spark to ignite (and being coil ignition it was a good blue spark). I'd never come across this problem before and it may have been specific to this model but you never know.....

[Steven.Carter]

If its kicking and huffing, could it be the timing?

[brenton.roy]

Logic says it's going to be something fairly simple. Particularly if it is nearly starting.
If it was running well before, had reasonable compression etc...

Useless search.. Found a wheel nut and a same sized rubber grommet, some crushed aluminium...
I'm guessing they aren't making spares for carbide tail lights any more..

[nevhunter]

The ignition timing is the only one that can slip. Haven't put a bit of diesel into the tank?

[adrie.degraaff]

If I only lived nearby.

Now if the inlet opens near TDC, it will run.
If the mag. point opens the other TDC on retard, it will run.
Drop 1 cc petrol in the plughole and start full throtle, it will run.

Testing the mag, (don't do this at home ), take the plug out, put you pinky finger in the plug cap, have that finger earth on the other side, and give a kick, don't thake your finger of earth !!!.
If you can stand this the mag is faulty.

[admin]

It lives ..
I have no idea why ... everything I looked at was good.
In the end, the petrol in the plughole got it into life ..................

Acid test is tomorrow morning when it's stone cold ....