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Have a look at the bearing sleeve in this head: https://www.ebay.co.uk/itm/Head-Head-Du ... 0667.m2042

Can you see George, it is completely different to the type fitted in bigger engines, and appears to have a flange that locates with the bevel tube.

Try put a space between "head:https//..." , to read
"...head: https//..."

You are a genius sir!

Duccout wrote:Have a look at the bearing sleeve in this head: https://www.ebay.co.uk/itm/Head-Head-Du ... 0667.m2042

Can you see George, it is completely different to the type fitted in bigger engines, and appears to have a flange that locates with the bevel tube.

From what I can work out this is the same as mine. I can only assume that sleeve should be tight fit in head and position is determined when flange is tightened up. Not a good idea.

Hello George

I pulled apart a scabby 160 head to see if I could shed some light on your issue. I think your issue is the hole in the head is a through hole as far as I can see. Is that correct and are you sure it hasn't been sleeved or modified in some way? I only ask this with reference to the witness mark on the head at the entrance to the hole.

As you can see from the pictures below, the Italian 160 hole is not through and there is a shoulder at the bottom of the hole. The housing is held between this shoulder and the shoulder at the bottom of the tunnel recess. With this design the shoulder on the housing is not used for holding the housing in place as it is on the larger engines. In some ways it is a superior design as it centres the tunnel and does lend itself to shimming in the tunnel recess.

Anyway pictures below, sorry they are a bit messy looking, I wasn't going to spend time cleaning it up







If you need any clarification or assistance give me a call sometime.


Regards Nigel

PS.
That 125 head pic posted is probably the same as the 160 head I posted, the thin land between the two bores is not that obvious. The top recess visible is where the bevel gear itself sits.

Nigel

Thanks for the input Nigel. I will have another look tomorrow and give you a call late morning.

Update on restoration.
Front end dismantled with ease. Forks removed and stripped. Stanchions in good condition, new seals to be fitted. Front wheel bearings and brake all good. Rim and spokes in good condition. Nice to have some good results. Headstock bearings only had 21 balls top and bottom not 24, some marking on bearing races, will have a look after cleaning see if they should be replaced. Time to start on rear end next.

Frame stripped and found to be in good condition. I will clean for painter but might be a while before delivering with this covid 19 problems we are having. Head bearings to be replaced. Swingarm pin shows minimal wear of about 0.003" (0.07 mm), bushes are a type of plastic and require replacement. Would it be better to fit bronze bushes. Also no grease nipples fitted, I think I will add two. Sides of bearing housings worn, will fit thrust shims to remove end float. Centre stand damaged will try to repair before looking for replacement. Rear suspension to be stripped and checked.
Camshaft and rockers posted to Joy engineering for refurbishment.
A good week with no major problems. When I have finished these jobs its back to engine strip / rebuild.

George, bronze bushes must be better, but I have never found anyone who could satisfactorily line ream them. Jesus Guzman in Spain may have new plastic bushes.