sludge trap clearing

[Minto]

Good morning to you all
ok, so after reading about the consequences of not ensuring this job has been done, and I have no knowledge of my bike's history, I realise that it is a job I'm either going to have to attempt myself or pay someone to do, and sooner rather than later.
I've had a search through the archives and though there is some fascinating and very helpful info on the subject, what I was after was really an account of how involved the job is and whether it is something that I should attempt with the skills and facilities I have/lack.
When I first left school some 36 years ago I worked for a short time in a garage but never did full engine strips and rebuilds, I have replaced cylinder heads on cars, bikes and trucks , have always done most of my own servicing on bikes and am reasonably handy though by no means expert with the  spanners. I have no machining equipment or skills. My garage space is limited but fairly well stocked with general mechanic tools (socket sets, spanners, gear pullers, valve spring compressors, mig welder etc).
I realise that I may find other issues in the process which need addressing, but generally if I were to start with this, how difficult is it to split the cases and get to the crankshaft? Following the clear out, am I likely to need the cases line boring? What kind of replacement items am I likely to require for the rebuild? How will I know if certain items (crankshaft, bearings, bushes etc) need attention?
If this seems likely to be beyond the scope of my limited skill set, how much might I be looking at to pay for this work to be done? again assuming that nothing out of the ordinary needs attention. I am hoping that I will be able to do this myself as Ive pretty much blown my bike budget for the foreseeable future.
Apologies for the length of my post, and further apologies if this has already been covered elsewhere.
Thank you in advance.

[AdrianJ]

I've just done this for the first time. My workshop is less well equipped than yours. No welder for a start.
Most of the dismantling was straightforward, the only difficult bits were lifting the engine out of the frame (simplified by taking the barrels and top end off first), getting the sludge trap caps off (they eventually came off easily with a good bolt extractor). You sound l8je you should be able to do it fairly easily.
The BSA gear puller is useful.
I probably needed more bits and work than you might. I've written in brackets how I knew it needed doing
New liners and pistons.
New big and little ends (and regrind). Already out at +60, decided to go back to stdj
New crankshaft bearings, primary chain and sludge trap caps. (Measurement, destroyed caps getting them off)
New valves, guides and springs. (valves sloppy, daft not to replace springs)
New oil pump, (old one was too stiff to turn, spacing washer was missing.)
All in all the engine was very worn, as is the rest of the bike :-)
I hope this is some use.
There are plenty of threads on here describing each of these activities
Still haven't managed to start it. Fuel seems to get to the reconditioned carburetter but no mixture to the cylinders and the magneto has gone away for reconditioning.
Regards,
Adrian.

[muskrat]

G'day Minto.
1st thing to do is get/download a manual.
It's not as scary as it sounds. There are a few checks to do first before you take the motor out. Crank end float and timing side bush need to be checked. A dial gauge on the end of the crank, push and pull to measure end float(0.002" or less is desirable). Write that down as shims will be needed to bring it back to spec. On the timing side a dial indicator to measure up and down (I use a lever on the oil pump to lift the crank). 0.001" to 0.002" is desirable (my A7 is showing 0.008" and still running, no horrible noises!!!) but if it's 0.004" it needs replacing (not a job for you).
Best to remove the top end whilst in the frame. Check pistons for rock (east west to check little end.
Now rip her out.
Things to check cam shaft and bushes, big end bearings and crank journals. I'd replace everything but that's me.
The sludge trap is the easy bit. When you get there post your findings.
Cheers
Adrian got in while I was one finger typing.

[Swarfcut]

Minto,
    If the bike is running well, there is a very good chance that apart from a set of gaskets and maybe some new tab washers here and there, that will be all you need. The previous posts show what happens with the big but.
 The  BIG BUT goes " But while I'm here I may as well replace...... At worst the crank bearings will be worn, the bores worn and the valves burned. The maggy will be full of oil and the clutch shagged. So it depends if you just want peace of mind or a full house resto.

 I would ride it gently as is, in the short term and don't worry too much. To get the crank out is a complete strip.

 If you decide to have a go, part strip the engine in the frame, rocker box, head, barrels off. Clutch and Primary drive all off. Timing covers, dynamo, maggy, all off. Then release the engine mounts, Engine and Box come out as one.. lift and wriggle.  Split the gearbox from the engine unit. All easy in theory. Most fixings are all Cycle Thread, threads into alloy are Whitworth.

 The oil pump is driven by a worm on the crank, which has a locking nut and tab washer, all are left hand thread. Draw off the pump, unscrewing the worm at the same time.

 The toothed pinion gear exposed now has to be drawn off the  crankshaft, using a thin jawed puller. Do not drive the crank end through the pinion with a big hammer, the crank end is relatively soft and will bend if roughly treated.

 Then its just a matter of removing all the retaining nuts and studs holding the cases, warm them with a heat gun if stuck with jointing, easing them apart. I lay the cases timing side down, crank nose through the gap on the trusty Workmate.

 Lift off the drive side case, then carefully turn the crank and timing side case over, crank drive splines through the gap then lift the case off the crank squarely to avoid any damage to the timing bush.

 The camshaft can stay where it is, as can the conrods. Support the pistons and rods to prevent any sideways load on the big ends. If the engine runs Ok, with no sign of big end knock, sideways slop is acceptable, but there should be no lift on the bearings. Up to 2 Thou is the wear limit.

 So, a set of old BSF/Whitworth spanners, maybe a Haynes, plus Draganfly's excellent exploded parts diagrams should get you on the way, plus Roy Bacon's Twins book if you can get one, and all the online how to videos. BSA Service Sheet 206 covers engine dismantling.
 Then there is the gearbox to consider.....

 Swarfy.

 

[Rex]

I found the worst part was getting the new plugs to screw into the crankshaft smoothly, square and far enough. Any force would have seen the little sods go cross-threaded and then I'd have been in the schtook.
As always, fine grinding paste worked a treat. A couple of degrees further each time gets there in the end. Labourious but worth it.
I also indexed and relieved the plug where it was slightly obscuring the oil way.

[Minto]

Thank you all so much for your replies and info.
I am going to attempt this. I'll just need to sort my garage out first (again)!!
I'll probably have to leave starting til at least the end of May, but I'll use that time to source the bits  that I know I'm going to need.
Ill use the bike carefully for now, and as always change the oil at least twice what is recommended.
I'm hoping I can get most of what I need from the Stafford show at the end of the month.
Thanks again for your input. Hopefully your generosity will continue throughout the barrage of dumb ass questions I'll be asking during the process.
Cheers
Jase

[Greybeard]

I found the worst part was getting the new plugs to screw into the crankshaft smoothly...
...As always, fine grinding paste worked a treat. A couple of degrees further each time gets there in the end. Labourious but worth it.

Grinding paste in the crankshaft oilway? Rather you than me!

[Swarfcut]

Minto. A word of caution.  At the Stafford Show be absolutely sure that you actually need the bits you buy. Don't buy because you might need it.
  Many parts considered marginal are perfectly capable of of continued use, so keep your cash.  Jumbles are great, but if you get a problem, then finding the seller again is well nigh impossible. Gaskets you will need for sure. A selection of Cycle and Whitworth taps and dies, cheap carbon steel just to clean up threads is very useful. Retain and reuse the fixings if you can, you can always swap out the visible ones later to improve the cosmetics.
 Pattern parts, as you probably realise, are a minefield as regards quality, material and fit.
 If you get stuck, just ask. We have all slid down this gravel road before.

 Swarfy.

 Additional... Have a look at a Plunger Flash ridden by that Distinguished Gentleman (with a big smile) link above.

[terryg]

Give us an idea of your location. It's possible you're not too far away from someone to ask, if you need to. But the forum remains a great source of know-how and the benefit of global reach.

[Greybeard]

....Have a look at a Plunger Flash ridden by that Distinguished Gentleman (with a big smile) link above.

[Butch (cb)]

I found the worst part was getting the new plugs to screw into the crankshaft smoothly...
...As always, fine grinding paste worked a treat. A couple of degrees further each time gets there in the end. Labourious but worth it.

Grinding paste in the crankshaft oilway? Rather you than me!

Made me shudder. I'd want to be mighty sure that was clean and sparkly and lovely afterwards.

[Rex]

It didn't really need saying though, did it?
After all, you use it for grinding valves in but would anyone say, "well, make sure you clean it all out afterwards".
A wash tank, compressor and pipe cleaners made sure it was all removed, but then a piece of unremoved sludge would have been just as harmful and that was all removed, too.

[Greybeard]

It didn't really need saying though, did it?

Sorry Rex

[Minto]

Hey Swarfcut, my shopping list for the show really consists of a new jacket, sludge trap plugs, gasket set and tools, spare bulbs, and maybe a oprv if I can find one, oh and a sump plate with drain plug, oh and maybe nice hat, and a t shirt for mrs Minto, lucky girl 😁
I’m not a million miles from Stafford so it would be rude not to go.

[Minto]

Give us an idea of your location. It's possible you're not too far away from someone to ask, if you need to. But the forum remains a great source of know-how and the benefit of global reach.

I’m in Wellington Shropshire. No, not Telford, it’s near Shrewsbury!!!