matchlessman

It'll never be any good with crap plates and a notched basket. It would have been better to spend the money that the armac mod cost replacing the knackered bits. All the armac does is alter the leverage ratio to make it lighter, which doesnt stop it slipping. The plates have got to be completely flat with good material. Minor notches in the basket can be dressed with a file. Its worth spending a few hours on it to make it as good as possible. You will be amazed by the diference. A cheap way to get a light clutch is to move the pivot point on the handlebar lever. Drill a new hole between the existing pivot and the hole for the nipple if there is sufficient meat. It does weaken the lever which may fail in a crash situation, but I ran that for a couple of years with the springs wound down to compensate for dished plates I couldn't afford to replace when I put it together.

The main thing I found with a cub is that the plates sometimes 'dish' this then acts as a spring preventing clean release and also limits the friction area. You must ensure all the plates are completely flat. I also found that cutting the clutch pushrod in half, polishing and case hardening the ends and putting a ball bearing in the middle made things smoother and lighter. Can't explain why, but it did. The idea was developed from somebody who did a top hat roller bearing for the pressure plate on BSA A50s /A65s, to reduce friction. SRM?

They are modern castings. If they are imperial thread I would suggest Harley Davidson if they came from the states that would add up. I'm not aware of any other current US manufacturer.

Definitely not AJS / Matchless. Suzuki?? If in decent condition they may perform better than AJS so may be worth fitting. They pass at first glance.

With a new motor and rings not yet bedded in you will get increased crankcase pressure, causing all sorts of oil leaks. I should review whats happening after its properly bedded in. I always found that the standard breathing through the cam was fine. As its a timed breather the engine effectively is under a slight vacuum as the piston goes up, which helps to suck the oil back in. If there's a lot of oil in the crankcase, that could point to a scavenging issue, are all the oilways clear? As far as the oil tank is concerned, don't fill above the return point or it will drain back into the engine and make it very smokey on start up. The oil level should be below the return, which enables you to see it is returning... and when its hot and has returned any from the crank case there's space for it.. You don't need vast quantities of oil in the tank, I ran mine with a Miller top tube tank and it was always cool enough. If you want more cooling, substitute the plastic pipes from the engine to the tank with copper microbore central heating pipe, with just 2" connector pieces at each end. Just change it more often as there isn't so much doing the work.

I'd echo the above. Make it as light and robust as possible. You will spend quite a bit of time picking it up after you've thrown it at the scenery in the beginning. Nothing more frustrating than falling off and breaking something that ends your day, and nothing worse than at the end of the day just wishing it would all finish because you're knackered after fighting a heavy heap of junk through every section. The mods are to make them steer, brake and go. There is no point in giving yourself an impossible task, you'll end up hating it and selling before you've even got going. Go to a trial, take pictures of the bikes, talk to the owners, they'll tell what is essential to make them rideable and what only gives a marginal improvement. More importantly they'll tell you where to focus your attention and cash. For instance you'll need to budget a minimum of

B&C Express at Potterhanworth, nr. Lincoln. They will manufacture sprockets for you, from pattern or drawing.

I've developed an easy way to strip ajs forks. Fasten the stanchion to something firm. You can use a vice, but I find the bottom yoke is pretty good (support bike so it doesn't fall over). Get a spindle / bar about 12" long that is a good fit in the wheel clamp (about 1/2"). Put the bar in the clamp then foot on one end and push down which compresss the rebound spring, then smack the other end with a hammer. Good to put something soft on the floor to catch the slider as it shoots off. Also make sure the top nut is removed or at least has the damper rod disconnected. Warming up the slider does help

Don't bother about an oil cooler. Mine runs pretty cool with a Sammy Miller top tube oil tank, even under the petrol tank. If its too hot for you, Use microbore copper pipe (central heating) between the engine and tank, with sort bits of plastic pipe between.

ATF, or the gear oil recommended for modern crossers.

My AJS (Magento ignition) tends to eat NGKs, but seems fine on Champions. It's obviously concerned about the Japanese invasion, if a little late. I do have to give it a good blat every so often between sections to 'clean the plug'. I'll be giving NGK - 4's a go to see if that works. From another angle, a road going B40 of mine used to get through plugs every 500 miles until I replaced the coil.

Thats a massive jump, from 18 down to 15 tooth. Roughly equivalent to going from 60 tooth up to 72 on the rear. (I think!!) Try to get a WD B40 gearbox cluster. Its wide ratio, giving low 1 2 and 3, but a higher (normal) 4th. You can keep standardish sprockets and still have low 1st etc.

The two hole are there for a reason.. the plain one is for the ignition wire from the points to feed through. The extended one is for the engine breather, which works from the cam. Its timed and blows into the outer case, and then out through the hole at the back. If you block them both you will have nowhere for the air pressure to go and oil will leak from everywhere..

Rear Sprocket is an easy mod, turn the teeth of fthe brake drum leaving as much meat as possible, then weld on a flange to abut up to it. You can then bolt on any size sprocket (can't go as small as you can with the standard drum). B&C express will make a sporocket to measure, to fit any internal Diameter. Advantage is its quick and simple to change gearing, without stripping down clutch etc (or half the gearbox on my rigid).

Manufactuing tolerances wouldn't allow.... Don't forget the little ball bearing in the cup.