Well what a disastrous rebuild this has been

[Pecon]

Hi Bikerboy

  I also had severe difficulty starting my GF after a full rebuild. I sat down with a friend and checked and rechecked everything that we could think of to no avail. In the end in desperation I opened the points fron 12 to 15 and the bugger fired first time. I still don't know if I advanced or retarded it but it sorted the problem  . While it may not be this don't give up as it's bound to be something simple in the end. Take a break and try again when the mind is refreshed.

Peter

[bikerboy]

You must have a low threshold of disaster, if a bike being reluctant to start after an overhaul counts as one.

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Yes I do consider probably having to strip the entireeengine back down to cure the wet sumping pretty disastrous lol

Most of the suggestions I have tried but thank you anyway so today I started from the basics. Tank off rocker covers off. Checked that all the valves were operating at the right time and that none of the valve clearances had tightened up for any reason.

Ignition timing seems close enough to get some reaction but without taking the timing cover off I cant check its accuracy perfectly.

I have decided to grab some easy start first and if that does not work then I will suspect the mag but it does seem to spark fine even if its not a perfect blue spark.

[Triton Thrasher]

All I'm saying is that a disaster would be if it started, then destroyed the big ends through lack of oil supply.

Or started, then seized the first time you met a headwind, because the rebore was too tight.

[orabanda]

Try a new set of plugs

[bikerboy]

All I'm saying is that a disaster would be if it started, then destroyed the big ends through lack of oil supply

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No that would be a catastrophe  

They are new plugs but thats not a bad call it wont be the first time new plugs have failed on me

[JulianM]

Just taken a great idea from a Maseratti 8C we have in the workshop.

In the oil supply line from the tank is a big ball valve type tap. Original!   and also a cutout switch for the mag when the tap is in the OFF position. Original!

This system is going on my bike!  No wet sumping and no silly balls to mess with!   I had already removed the std ball and spring from behind the pump and had the idea of a tap that gets in the way of the kick but now I have a better idea thanks to the Massa Brothers!

Julian

[gavinoz]

Is it the faintest bit possible that the oil return and feed pipes are the wrong way round?

gav.

(Only Musky knows where I live so I can say really dumb things knowing you wont recognise me if you see me)

[muskrat]

I think if that were the case Gav the motor would have died already. The return pipe stands high in the tank and therefore wouldn't feed the motor.
Nice try though.
Julian, I think that method has already been used by a forum member. Would have to look back through a lot of posts to find who.
Cheers

[bsa-bill]

In the oil supply line from the tank is a big ball valve type tap. Original!   and also a cutout switch for the mag when the tap is in the OFF position. Original!

Some folks swear by this method, it's one less ball valve to worry about but one more switch to worry about ???

I put my faith ( I know some will disagree) in the percentages as did BSA and the chance of one of the three ball valves BSA fitted failing is very very slim, and defo less than a switch (which might have been made by Lucas, Wipac or dare I say worse - an Italin design 

[Butch (cb)]

Mine did almost exactly 250 miles before sizing solid on the main timing bush.

[A10Boy]

Julian, I think that method has already been used by a forum member. Would have to look back through a lot of posts to find who.

I have a tap / switch on my AJS. Works really well too. Made in uk by a chap called Dove. PM me for contact details.

[lawnmowerman]

I bought a Dove tap but have not fitted it yet. It is quite large and it is not easy to fit neatly - the obvious place is above the gearbox which would look awful so I would like to fit it below the oil tank but there is not really enough space. The other option would be below the gearbox but may involve burnt fingers on the exhaust.
Trouble is the oil hose spigots on the tap are a larger bore that on the A10 oil pipe so reducers will be required and it will make it look like a dog's dinner with all the extra fittings and clips.
If anyone has fitted one I would be grateful for any tips or pics.

Jim

[bikerboy]

Well after lots of messing the plot thickens.

I am fairly sure I dont have a spark or fuel problem and as I said in my original post the bike feels "odd" when I kick it over. Dropped the sump again and another pint and a half of oil came out of the bottom. Now when I kick it over it does not feel odd and actually feels ok.

This leads me to believe that the whole problem is down to wet sumping. What I have done so far is left the sump off with a perfectly clean container under it. Filled the oil tank back up and now I will check it daily to see just how much oil is pouring into the sump. If as I suspect its lots then my first move will be to change the oil pump. I do wonder (as I kicked it over a million times before trying to start it just to prime it up) if the oil is going down but not being pulled back up ?

I have sorted thru my parts boxes and have produced half a dozen oil pumps so depending on just how much oil I find in my container will decide if I should at least change pumps before trying to start it again.

God I hate motorbikes for a couple of quid I could but myself a nice little scooter   

[wilko]

Loose oil pump studs.

[beezermacc]

Take the plug caps off and find a way of holding the ends of the HT leads about 2mm from the tops of the plugs. You can tape the HT leads to the plugs and bare the wire and bend it until it nearly touches the plug top. Kick the bike over and look for a spark at the plug top between the HT lead nd plug top. If you see a spark then there must be a spark at the plug tip as well (unless the plug is badly fouled which won't be the case with new plugs). If it sparks you can turn your attention to the carbs. I agree it is unlikely to have a fault on both carbs but I would expect both plugs to be soaked after kicking for a while. Also try a squirt of neat fuel down the plug holes.