[andyfrost]

Replacing the big end rollers is a horrendously expensive job , remember it has to be re-balanced , which requires specialist equipment , along with specialist prices. If it appears reasonably smooth , and no undue play , I would just thoroughly clean it. It will run perfectly OK with a small ammount of wear , and as you’ve said it will not be used in anger anyway.
To replace the main bearings is relatively inexpensive , these along with the gland seal bushes are far more important to good running.

Andy.

[andyfrost]

Once you’ve removed the flywheel and clutch (and obviously cylinder barrel) , you should be left with two taper ends , remove all crankcase joining bolts. Using the clutch retaining nut , wind it on to protect thread, hold the crankcase by the top half and GENTLY tap the crankshaft with a lead or hide mallet and it “should” move out , it may leave the main bearing in the crankcase , either way it doesn’t matter.
Above all else do not force anything , take your time and if need be leave to soak in a barrel of red diesel for a week.
The magneto will be no problem as all parts are still readily available , Paul Childs at Meetens will put you right on parts , they will not be cheap , but it will ultimately mean a machine that will start and run easily.

Good luck Andy.

[andyfrost]

Memory is very sketchy , as it’s quite a while back when I parted with mine. What I can tell you is one mount used the aux petrol intake(the one right next to the exhaust in image 19) which was threaded , to the rear from scant memory there was a fabricated bracket that combined the throttle cable guide.

Andy.

[andyfrost]

I think you’ve misunderstood me , I’m talking about the shroud in your image No3 , it was merely a form of “carb cover” and had nothing to do with petrol parrafin. The one I sold awhile back had it fitted , but I would guess that it was one of those parts that were not always re-fitted and subsequently lost , as it served no real purpose.

Andy.

[andyfrost]

Always good to see one of our more unusual machines , very nice job. Did yours have the original carb shroud , or was this only fitted to the later models.

Andy.

[andyfrost]

Try re- checking your ignition timing.

Andy.

[andyfrost]

In the top of the throttle slide there is a screw , turning it down will weaken the mixture , and raising it richens , although I suspect from your description it is a timing issue.

Andy.

[andyfrost]

Joe , the b10 carb was used on the MK10/12 and 15 , and was used on a whole host of machines , so far more common , and hence easier to source parts.

Andy.

[andyfrost]

Joe , at some point in its life it’s had a change of carb , the b10 is not the original carb fitted on a Bantam. That’s not to say that it will not run or perform perfectly OK.
The correct carb for your model is an S12 , which requires the correct manifold. It’s entirely up to you if you want to keep it all original.

Andy.

[andyfrost]

Any chance you could post a photo of your carb/engine.

Andy.

[andyfrost]

Meetens should be able to help.

Andy.

[andyfrost]

Alan , many thanks , lovely photos , there is still something special about an old black and white photo.

Andy.

[andyfrost]

From your description I would be inclined to look towards your ignition/timing set-up.

Andy.

[andyfrost]

With a small ammount of modification the spring from an old type Suffolk mower will do the job.

Andy.

[andyfrost]

I can’t fathom out how that is possible , if you just need it as a working machine , it won’t come to any harm , with CAREFUL use , to use it without the electronic govenor.

Andy.

[Author]

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