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Mountfield 463 mower timing

Discussion in 'In the Garden' started by hardtail, 15 May 2018.

  1. hardtail

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    Hi ive just brought a non runner mountfield which looks very clean ,ive managed to fix most the issues inc bent crankshaft carb strip ,new plug oil and blade and and got it running but just not perfect yet as the high and low throttle isnt really doing it ,as the crankshaft was bent i suspect the key maybe split under the flywheel as the timings a little lumpy also the starter motor struggles to turn the mower over would i be right thinking that could be the timing out a little or the valve clearance wrong.The engine is a rm65 and was hoping someone may know what the tappet clearances may need to be many thanks in advance
     

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    Last edited: 15 May 2018
  2. hardtail

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    one other thing on the idle jet which is he plastic piece under the idle screw i did have a couple of splits orings which was the fault of the high reving when i got it going but managed to grind a couple of orings down to get me by does anyone know where i could purchase these from
     
  3. Burnerman

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    If the flywheel key had sheared, the engine could fire occasionally but wouldn't run.
    Best pop the flywheel off if you can for a look see.
    May I ask how you dealt with the bent crankshaft?
    As for valve clearances, set at .10 mm for a start when hot.
    Can you measure the voltage across the battery when you are cranking it over?
    John :)
     
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  4. hardtail

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    hi john use a alloy hammer :0 crude but did the job and now runs true ,thought it was worth a shot after watching a couple of red necks do it on youtube and thought id risk the 30 pounds which i payed for the mower . only issue really now with the mower is the ticking over has a slight hunt to it and the high and low on the lever dosent really do much in way of speed change and the starter is struggling to turn the engine sometimes it clicks sometimes it turns the motor it seems as if there something dragging but i seen the timing could be the fault
     
  5. hardtail

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    ill measure the battrey tommorrow ,it is smaller looking to what should fit in the bay but even after a charge to 12.8v its the same when starting ,ive also tryed turning it over connectted to a power pack jump starter which was also the same.With overall condition of the mower id say its probley had a season if that ok work so im hoping the starter motor is ok as the mower basically looks new. and will hopefully replace my old mountfield when the holes in the deck get anybigger
     
    Last edited: 15 May 2018
  6. Burnerman

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    Well done with the crankshaft, I've replaced quite a few but never tried to straighten one!
    Your idle problem is sure to be a carburettor issue I think, and I'm not too sure about the plastic piece under the idle screw. ...a picture would help?
    If you can provide the starter motor with plenty of current, there is a chance it's getting lazy, and the voltage should drop when cranking. Look for 13 to 14 volts at the battery with the engine running.
    Have a look at GHS Ltd for carb spares and replacements!
    John :)
     
  7. hardtail

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    Cheers for your help john I'll give
    Ghs a bell today to see if they can help on the tiny o rings and I'll pop the carb out today to pop a pick up of the part I mean , when I first got it going it was running very high and found this plastic jet blocked and the oring perished but it a lot better now just a slight hunt so hopefully I can fix this without a new carb as all the ports are perfect other than that .I'm hoping the timing is the only issue now
     
  8. hardtail

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    well today ive removed the flywheel and all is good there no broken keyway :) also tryed the mower with a charged power pack and it seems to turn over slowly but did go so ordered a new 5.5 ah battrey so will check power when turning over then .is there a charge circuirt on the mower then john like an alternator .iIve also stripped the carp and added a picture of the small plastic jet i was on about and spoke to ghs but they couldnt help but could supply a carb at 76 plus vat ,just cant warrent buying a new on when i know this ones good ,just a risk on the orings in the future .currently got it running ok with only a slight hunt so will have another play if i can source some small oring just incase ones letting fuel buy or starving it
     

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  9. Burnerman

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    Your mower is likely to have a very basic charging system, did you notice a coil or two under the flywheel? If you did, there's probably one single wire coming from the coil with a diode in it. Either way the meter voltage should rise a bit when the engine runs.
    Pity about that jet issue though, it's a poor push in design and the O rings do need to seal.
    John :)
     
  10. lostinthelight

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    That jet looks the same as the one on Honda pro engines and is often overlooked when diagnosing starting issues .Its kept in place by the tapered plastic idle speed screw.
    litl
     
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