Simar 56A Rototiller – Serial No. 561473

[wristpin]

To remove gudgeon pin (wristpin) remove the clips part number 10297, see parts manual plate 2 for illustration.

If it’s an alloy piston, with clips removed, suspend it in a pan of boiling water for five minutes and it will probably expand enough to allow the pin to be just pushed out. Failing that make a tool similar to this to push it out. No apologies for its rather crude appearance as I made it in about 1960 when playing with Lambretta scooters. Amazing how many pins it’s pushed out on a variety of engines since then.

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[john-e-w]

Now that you have got the piston out – what happened to the split pin that was in the lower barrel?

John E-W

[aquila787]

John E-W

Every day’s a school day. What I thought was a split pin is the bottom piston ring divider. I attach a photo.

John

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[charlie]

The split pin is there to stop the rings turning in the groove. As a 2 stroke it is important that the ring gap does not line up with any of the ports in the cylinder bore, this could happen if the rings did not have the split pin to prevent then moving.

[wristpin]

The split pin is there to stop the rings turning in the groove. As a 2 stroke it is important that the ring gap does not line up with any of the ports in the cylinder bore, this could happen if the rings did not have the split pin to prevent then moving.

Seems a fairly crude way of achieving the desired result. Is the split pin an original feature or some “Bush mechanic’s” bodge after a happening of some sort?
Even Villiers have a more elegant way of doing it.

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[aquila787]

Hi again

Just wondering can the springs for the tines on this machine be purchased anywhere. If not I’ll draw them in Solidworks and see can I get them made.

The piston and cylinder is with engine remanufacturer at the moment.

John

[charlie]

As far as I know the springs are not available off the shelf. There are two types of spring depending which style of tines you have. If they are the type that are round cross section and hook onto the spring it is part number 634. If they are flat bar in cross section and attach to the spring using a pin that locates in a casting held in the spring it is RD310. I have had a quick look at my list of drawings held at MERL and they have the drawing for RD310 but I could not see one for 610.

[aquila787]

Hi Charlie

It’s the RD310 I have. Could I get the drawing for that spring. I’ll do a Solidworks drawing of it if it’s not already in Solidworks and make available free.

John

[charlie]

John, you will need to contact the Museum of English Rural Life (MERL) at Reading, I only have a list of the drawings. The drawing you require is drawing number RD.310 the MERL reference is TR DX 493/1.

[aquila787]

Thanks Charlie

[aquila787]

Hi

The engine builder is finding it very difficult to remove the piston ring pegs on my piston (part numbers 5268 and 5269) Have any of you done this or are they available to buy. I seem to remember reading somewhere that there might be a fellow in Switzerland selling some parts for these Simars. I attach pics.

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[charlie]

I am fortunate, so far, not to have had to rebuild an engine to that extent.
Looking at the parts list diagram the pin will only come out one way. If it was me I would heat the piston to see if that helps.
I am not aware of anyone having spares, but there is a drawing held at MERL, drawing number 5269 MERL ref TR/DX/1607/8/5269

[aquila787]

He’s going to drill them out and tap the hole for a grub screw as replacement. I suppose it’s worth a try. I’m hoping he’ll put loctite on them and if he drills right through that he’ll put a grubscrew with a lock washer on the back as well as the loctite.

John

[andyfrost]

Does your man really think that piston is repairable , from the photos I would say it’s a bit unlikely , it’s the breakage between the ring grooves that would concern me most. Were it a fourstroke , then yes there are ways you could have gotten round it.

Andy.

[aquila787]

Andy

He thinks it’s repairable…..I don’t know myself…..I’ve seen a worse example of piston on here I think which was repaired. It had a large hole in the top. I’ll find a piston somewhere if all fruit fails. I know at the end of the day it will cost more than I can buy a good working machine but that’s not the aim. I want to experience the restoration of an old machine.

John

[Author]

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