Hartop M

Discussion in 'Help Wanted' started by matth, Sep 29, 2013.

  1. matth

    matth New Member

    Picked this little motor up today, we had it running briefly but I don't think the mag is the full shilling, so I will try my spare one on there and see if that makes it a bit less tempermental!

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  2. Numpty1

    Numpty1 Member

    Interesting Matt, it looked like this the last time I saw it 11 years ago.
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    Erm, not sure about the carb. Looks to have lots of original Hartop spec bits but may not be exactly the right one. Check and see if it has 2 jets or 1. I may have had a hand in making it up but the old brain box is fading a bit.
    Was very tight to turn over, has that been cured? and I see the end of the key is missing now. If you plan to do something about that be careful as the keyway is very shallow in the crank.
    Dates to circa 1936, standard 1 1/4hp M type with the 1 1/8" main bearings. Probably originally tank cooled which is rarer in the M types.
    Good Luck.

    Mark
     
  3. matth

    matth New Member

    Hi Mark, thanks for dating that, yes the keyway is incredibly shallow, the keyway in the flywheel looks fairly mangled as well now, I don't think she seemed especially tight, I think the carb is original but im not sure, it has certainly been though the mill anyway, I think the tank is fabricated up, I did clean the carb and got her starting on the flywheel before the bodge up of a mag drive disintegrated in a flurry of aluminium shards and gutter bolts, I also noticed the mag bracket is cracked as well, I think it has been fairly recently repainted since that picture as well, I will get it sorted out eventually, it came off a bloke called Jeff Rogers from Taunton, did it used to be yours?
     
  4. Numpty1

    Numpty1 Member

    Nope that's the guy that owned it then. Just hope he is OK having his name on t'internet. Thats why I think the carb is a make up. I may be remembering the wrong engine here but I know I tweaked one for someone, and I clearly remember that engine didn't run that day. Unscrew the top and look at the slide, should be solid brass, dull chrome? plated. To be exactly right should have a small flap choke rather than that great air cleaner/choke. Also bottom nut is wrong as it has the extension to accommodate the jet as used with a needle. Hope this all makes sense.

    Mark
     
  5. matth

    matth New Member

    Yeah it is just solid brass, I was thinking of putting a seagull outboard choke assembly on there, wouldn't look out of place I don't think, she seems to run OK anyway, but when I get the mag drive sorted and it up on the trolley I can do some fine tuning then
     
  6. matth

    matth New Member

    Am slowly getting a few bits done to this, nearly finished making a decent mag bracket for it, but I have just noticed the crank is 1'' dia rather than 1 1/8''
     
  7. matth

    matth New Member

    I have to make quite a few new bits for it, I will make the drawings I have had to do for the mag bracket, water jacket plate, mag drive coupling and bolt on pulley available for anyone else who may need them whos in the same sort of situation as me!
     
  8. Numpty1

    Numpty1 Member

    Yes that's right Matt, Crank is smaller on the mag side. Will still have an 1 1/8" bearing though with the step the bearing side of the crank skew gear. Here are a few pics of the mag drive itself. Boss is 1 7/8" dia x 15/16th long. Lugs are 2 1/2" dia x 15/16th wide and 3/8th thick. A simple turning job and just mill the sides off afterwards. The Magneto fitting likewise can be a turned disc 2 1/2" x 5/16th with the taper to suit your mag, then mill the sides off to 15/16th width. Screws are 1/8 whit and 3/16 whit for fixing bolt. Note the square head.

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  9. Numpty1

    Numpty1 Member

    BTW Matt what are your plans for the old mag bracket? I could do with a spare as a pattern for anyone wanting a casting done.

    Cheers

    Mark
     
  10. matth

    matth New Member

    Thanks Mark, I will change my design then, mine was completely different and was more like the 2 parts of the drive on a shafty Lister D, I was just worried about my way not allowing for much misalignment of magneto and crankshaft but that way will get rid of that problem, any idea of what to use in place of the fibre disc, we have some bits of 8mm thick rubber sheet that might do it, failing that could do it in nylon
     
  11. matth

    matth New Member

    It was gonna go in the scrap bin! it is cracked all the way along, and the holes have been butchered to allow the hovis mag to fit, but it was only held on by 2 holes and half the mag was hanging over the back

    Your welcome to it if you want it!
     
  12. petternut

    petternut Administrator

    The disc looks like leather to me and many makers used leather. I use leather and get mine from the tannery at Colyton.

    cheers
    Roland
     
  13. Numpty1

    Numpty1 Member

    On the Mag Bracket, Yes Please!

    For the disc the originals are leather, I have some and can make you a disc if you so wish. 8mm rubber sheet sounds a bit thick but would do 5mm would be better, nylon would be too inflexible.
     
  14. matth

    matth New Member

    Ah I see, didn't realise it was leather!
     
  15. matth

    matth New Member

    Ok I will post it at the weekend I expect, I shall hang fire with the disc at the moment though because I might change the PCD of the holes as on your coupling the holes are nearly breaking into the side of the hub, so I might move the PCD out by 10mm or so, and make the diameter of the part that will form the lugs slightly larger as well so there is enough meat there
     
  16. Numpty1

    Numpty1 Member

    Be careful unless you have made the bracket deeper the disc will foul the bracket. The holes do come out on the edge of the boss but I have never seen an original one busted yet and a steel one would be stronger anyway. Just have to be careful when drilling through. The PCD of the holes is 1 7/8. but you could easily make the boss slightly smaller and move out to 2" PCD without altering the overall diameter.
     
  17. matth

    matth New Member

    Ah that's the right PCD is it, I just took a guess at mine, the centre height of a hovis mag is at least 40mm, so I can go up to 80mm without fouling, my bracket that im making is quite thick so I can always mill a groove in it to allow it to clear if I do have problems, but I think I still have a bit of room
     
  18. Numpty1

    Numpty1 Member

    Just been out and cut you a piece off big enough for several discs and got a soaking too! B**** Weather.
     
  19. matth

    matth New Member

    haha cheers, its cr*p aint it!
     
  20. matth

    matth New Member

    I am just wondering whether to convert back to tank cooling or look into having a hopper fabricated, the current hopper is an awful job and leaks like hell, im just wondering how much it would cost to have one made, will get the engine running first and see if I like it though!
     

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