AJS Mechanic need - Sydney Austraia

[Malleon]

Was she looking over your shoulder as you typed that?

[Merlin]

[johnnyb]

I have tried removing the metering plugs and replaced the oil distributor with a later model type (with cut away). Both did not fix the issue.

I removed the cylinders again today and removed the pistons. I re-checked the big end movement and they are worn. There's rocking movement and up and down movement which is not good!!!! I am very confident this is the cause of my issue. I was hoping this wouldn't be the problem because I wasn't looking forward to a bottom end rebuild.

Time for a new post asking information regarding this job

Thank you all again for your valuable advice.

BTW: the bike is a 53 model.

[Eric]

Yes if you can detect any up and down movement its a definite, the rocking was good enough for me. Don't worry about the magnitude of the job its really quite simple and straightforward just take you time and check everything as you go along both when dismantling and re-building. You will need help to get the engine out of the frame and back again or I did you maybe bigger and stronger.

Hint 0. If you do not already have it get a copy of the workshop manual. Click Here for the Manual

Hint 1. Do not order any bearing shells until you find out what size the crank has to be ground down to. I say this because mine had to go down two sizes because it had worn oval. Also check what shells are available as well.

Hint 2. Take time finding your engineering company to do the grinding, make sure they understand the need for a radius in the corners as per the diagram in your workshop manual. Clean out the oil-ways and sludge traps both before and after re-grinding.

Hint 3. If finances permit have the finished crank dynamically balanced it will make the world of difference to the finished result. You will need to have already decided if you are keeping your pistons, con-rods, gudgeon pins as these are required for the balancing process.

That's enough for now by the way why not join the ClubEdited by - Eric on 01 Aug 2010 12:26:13 PM

[wilko]

I wouldn't trust any ol' engineering shop to do the regrind. We've all read about plenty of bodgy radiusing. Unfortunately i can only recommend a chap here in Victoria who does plenty of twin stuff who gives it to his local grinder!His name is Greg Ditchfield no. 0408503920 he might guide you.

[johnnyb]

Hello Eric/All,

Thanks again for the tips. I'm sure I will be asking more questions.

I think it will be a good itea joining the club.

cheers

[laxy]

Hi John another little tip on re-assembly
when you are ready to fit the new main bearing outer races into the crankcases put them in the freezer the night before and after heating each crankcase half in the oven {get them as hot as you dare}slam the cases down hard onto a wooden board or work bench to shock them out.
The important bit is to make a note of which outer race fits to which inner race. Although they are the same they are subject to manufacturers tolerances and if you do the same as I did you will never get the crankcases together
hoping this saves you hours of anguish, Keith

[Adrian Pancaldi]

Hi Johnny,

I only quickly browsed this thread. If you are up for a regrind. L.W.Parry in Arncliffe,Sydney are aware of the radius needed and to grind in the rotation of the crank. If you are still stuck for an expert I can put you onto a couple of people, though would prefer to give their details by P.M.

Goodluck
Adrian