Well what a disastrous rebuild this has been

[bikerboy]

beezermac

Since I have got all the oil out of the engine and have been able to give it a good kick the plugs are getting wet.  Obviously I had the sump off so was kicking it over without the ht leads on just in case it fired.

I have had the plugs laying on the head and the lights off in the garage and the spark is pretty good and totally consistent. I am fairly sure it will start as soon as I cure the wet sumping problem.

Changing the oil pump and leaving the sump off to see if the oil still drains thru is my first priority.

[JulianM]

Good luck mate!

We have all got our fingers crossed for you I'm sure!

julian

[RichardL]

Having a hard time thinking that wet sumping is somehow totally prevented firing. You mention that a pint and a half came out. I have made the mistake of starting up when there must have been more than a quart in the sump. Oil spewed out the breather hole but the bike was running nonetheless. Sorry I can't offer any new ideas that haven't already been mentioned, but it seems the problem lies elsewhere. That said, I hope I'm wrong and the bike fires right up and the next report from you is about how you can't get the bugs out of your teeth.

Richard L.

[KiwiGF]

Not getting a  good turn when kicking it over i guess could be caused by wet sumping if another factor is in play e.g. clutch slip... i mention this as after a rebuild a mates a10 would not start and clutch slip was one of the causes. Once that was fixed the next issue was plug leads needed switching, then mucho happiness it started    

[RichardL]

i mention this as after a rebuild a mates a10 would not start and clutch slip was one of the causes. Once that was fixed the next issue was plug leads needed switching, then mucho happiness it started  

Is it absolutely, positively, beyond a shadow-of-a-doubt certain that the plug leads are not reversed? No disrespect intended, because I know this has already been asked, but so many exhausted possibilities eventually bring back old questions.

Has "bent pushrods" been proffered?

Richard L.

[fido]

Not getting a  good turn when kicking it over i guess could be caused by wet sumping if another factor is in play e.g. clutch slip... i mention this as after a rebuild a mates a10 would not start and clutch slip was one of the causes.

Yes, that would account for it feeling OK with plugs out but odd with them in. There is a B40 in my shed that won't start. It has such a silly little kickstart lever that I've given up trying to do anything with it.

[RichardL]

There is a B40 in my shed that won't start. It has such a silly little kickstart lever that I've given up trying to do anything with it.

I'll be 'round to pick it up in the morning.

Richard L.

[Zen Up 67]

Then try some old plugs!

Your mag spark sould be nice and BLUE!
Yellow sounds dodgy, did you say the mag has been rebuilt by someone who knows how to do them?
Just thinking about mag insulation issues, all those things that needs insulation!
Poor armature, poor capacitor will give you a yellow spark!
I once replaced my dodgy armature with a brand new one from Lucas, hells bells before the kick start was half way down it fired up so quickly it shocked me!
I once totally rebuilt a pre unit Bonny with no expense spared, new twin carbs etc. It would not start for days, then I tried lifting up the 2 needles and it ran. Months later, I dropped the needles back down to their proper positions.

Is your engine too tight to run?? Did you try to turn everything as you fitted each component?
I once rebuilt a B40 with a tight new main bush. As you tightened up the crankcases it kept locking up the crank. I would never have started if I hadn't "run it in" by turning it for hours on a lathe with lashing of WD40 and oil until it was lovely and free. Definately no end float and it had that lovely BSA single whistle you rarely hear anymore! That one would never have started on the kickstart.....
My A7 would not start after a recent top end rebuild, if you have good compression, inject/tip a small amount of fuel down the plug hole kick it over a few times to gas it up, then try it.
A few things to try but I think it will be something to do with the funny feeling you have, it usually is!
Best of Luck

[bikerboy]

Is it absolutely, positively, beyond a shadow-of-a-doubt certain that the plug leads are not reversed? No disrespect intended, because I know this has already been asked, but so many exhausted possibilities eventually bring back old questions.
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I know for a fact that the leads are not reversed but just in case I was wrong I have tried it countless times with the leads on the other way round as well, not so much as a peep out of it.

Progress report (or lack of it). A change in oil pump seems to have really helped with the wet sumping problem. After two days with a container under it there was virtually no oil in the container.

It is better to kick over now but its still damned hard work. The whole bottom end span lovely and was rebuilt by Tony at the rebore shop in Farnham (who has an excellent reputation). The bores were resleeved and I gapped the rings. Without plugs it spins lovely and I do think that once it has started it will be fine.

Still no joy starting it and I am beginning to suspect the magneto. I rebuilt that personally (I was an auto electrician for 22 years and have rebuilt countless alternators and dynamos). The points are new but the armature is old. It has new bearings and insulators but the spark is not a killer blue it does seem a bit weak to look at.

Firstly who is the best person to send it to ? I might be capable of putting it together but do not have the expertise or equipment to rewind the armature.

Secondly has anybody any experience of the SRM Boyer electronic conversion ? Or one of the other after market conversions for that matter ? I have already converted the bike to 12 volt so one would fit straight on and I am tempted.

I do have a box load of armatures so might be able to salvage something from there I suppose.

I am fairly convinced it cant be anything but the mag as IMO even if the carbs were a mile out I would still expect some sort of reaction even if it was just a big damned bang.

[RichardL]

Bikerboy,

If your not sick of hearing from me, here are few thoughts about your spark and mag. As I understand it, a bad armature that sparks for startup shows its bad side when it gets hot. If this was the description of your bad armature, I think you would expect some firing and maybe startup. On my bike, it kept getting progressively harder to start until it was ridiculous. My spark was weak. My magnets were weak. After I remagnetized, I disabled the cap inside the armature according to the instructions from Brightspark Magnetos and installed their EasyCap. No more starting problems. I tend to think it was a combination of remagnetization and the EasyCap. In any case, for under 15 GBP, it's a cheap experiment.

Now, about the hard kicking. Was the kickstart quadrant changed in the recent rebuild? If it was replaced with the type having flattish rather than pointy teeth, this can be a source for hard to impossible kicking, where the kirkstart arm does not return to normal position.

Dying to hear the ultimate answer because I am so infrequently the source of the best guesss.

Richard L.

[terryg]

I've had good magneto service from Tony Cooper, whose details are on the forum somewhere. Fortunately I was working close to his Halesowen base and was able to call in rather than posting stuff. He has the gear to test a mag fully.

[KiwiGF]

Hi bikerboy yr own suggestion of rigging up a temp coil ignition sounds very good to me now....if it fired it would eliminate a lot of other possible causes.....

[bikerboy]

manosound

I never get sick of chatting bikes its in the blood 

No there were no changes made to the gearbox except new gear lever and kickstart bushes. I took the covers off had a look flushed it out and put the covers back on. I will say the kick jams more regularly than I like but thats possibly cos I have kicked it over about 5000 times 

Fortunately the weather has been great here (sunny Berkshire) and I have been to busy roaring about on my Tribsa to give the A10 my full attention.

As for the "hard to kick over" thing a friend of mine has tried it since I cured the wet sumping and he insists I am just being a wimp lol.

[bikerboy]

Well now I really am baffled. I had convinced myself that the problem was the magneto and as i said in an earlier post I had stripped it and replaced bearings etc.

I removed the mag and checked it over. The points gap is identical both sides (12 thou) and on the bench spinning it lightly by hand I get a great spark on both plug leads. You can actually hear the spark, its nice, its blue and it appears fine.

Now I have to refit the damned mag and retime the stupid thing.

[RichardL]

Bikerboy,

I suppose if you weren't already bald, you've pulled it all out by now.

I was wondering about compression. In searching this topic, I notice you've only mentioned compression once, and that was to say that the hard kicking made it feel like 12:1 compression ratio. Maybe that was due to other circumstances and not related to cylinder compression. For grins, maybe it would be interesting to do a compression test, just in case? Sorry, if this is old news and that I am the one who should be getting a "hard kicking".

Richard L.