Decided to start the new year with action so spent a hour couple of hours working on the Atlas on New Year’s Day.
Took the old carb off and after some cosmetic cleaning (the outside only) of my spare carb on it went. The new carb looks fine and the application of Duck Oil to the choke lever and throttle valve means it works very smoothly. The choke has a fresh cable banjo bolt which along with a new handlebar mechanism I think I have in the box of spares means I can restore the choke to original factory operation i.e. I can dump the bodge I rigged up using a bent coat hanger!!!
Inspection of the old carb showed that only the nearside pump worked – this is the side that wasn’t affected by the split inlet rubber. I plan to get some carb cleaner and get to work on restoring this carb. I think restoration will involve quite a bit of work to clean the black deposits.
Anyways it was back to the garage to on Saturday to see if the Atlas would fire up. A depressingly familiar morning revealed itself…With the new remote petrol reservoir rigged up I started to pump the starter (with the RGS battery similarly rigged up to ensure I had enough juice to run the starter) but the sprag clutch was toast and just spun on the shaft. Damn it was going to be back to stripping that down before I could test out the new carb. Then I heard the drip, drip, drip of petrol and saw that the newly installed carb was leaking away all over the starter – off with the carb for inspection. This showed that the diaphragm had been removed from the carb so I duly swopped over the one from the original carb.
It pissed me off and I hope the tomb raiders haven’t taken anything else off the damn carb. I suppose the good thing is that the removal of the diaphragm was obvious so at least I didn’t get everything hooked up and then couldn’t find out what the problem was.
Examination of the sprag showed two plungers had seized in their bores and one spring had been broken. A 4 roller sprag just won’t work…Anyways the Leo Zimmerman sprag is good in that you can dismantle it and push the plungers out – fresh springs, plungers and some better, albeit used, rollers installed we’re good to go.

Plunger seized onto bore plug – separate plug and plunger shown alongside (feature only on bespoke Zimmerman sprag)
Well Sunday arrived and I decided to head off to the garage to fire up the Atlas before breakfast only to be confronted with a slipping sprag still! Examined the sprag and can see all of the rollers are damaged so hopefully a new set will cure the problem.
Spent time looking for the bits and pieces to put together the replacement Zane sprag I ran a while back but in the end couldn’t find the centre bearing and so gave up – damned garage is still such a mess!!! I also took the alternator cover off the spare engine to set a perfect sprag setup. The trouble was that without a means to lock the engine I couldn’t get the crank nut off. Decided I was getting ‘pissed’ with the whole episode and so walked away. I have a bearing shop nearby so hopefully will be able to source the 10mm rollers and have another go tomorrow.
Grrrrrr
Nick 🙂