Strange String of Events

Discussion in 'Mech Tech' started by PIE, Jul 25, 2019.

  1. PIE

    PIE

    Its the hottest day on record.
    1500 Sp with 30 Pict Carb
    Drove from Stratford to Shrewsbury
    Stopped at the Bull at Inkberrow for a pint and at Kidder to fill up.
    Drove Ok, pulled on the drive, the tickover was slow and the oil and Gen lights wire flickering.
    Suspected overheating so turned it off.
    When cold tried it again, warning lights came on but not even a click on ignition.
    Got out the multimeter, Ok to Starter, shorted the starter with no ignition, it turned. Suspected the switch as the loom is new. It then started on the key but only just ticked over, Cheched carb and the snail cam was pointing down with the stop over the top. Turned it back and everything is OK.
    Is it heat related?
    Is it bad luck and a coincidence??
    Is it something I have not thought about????
     
  2. mikedjames

    mikedjames Supporter

    The choke cam should not go over the top and wedge, there is meant to be a roll pin through the cam stopping it from going too far.
    The choke being wedged on would explain poor starting and idle as it will be far too rich at idle for a hot engine.

    If you ever think its overheating speed up idle a bit till lights go off on the dash.
    If they dont go off ..STOP the engine! as no oil pressure or maybe fanbelt issue
    Then with lights off keep it there with foot lightly on pedal for a few mins.
    The heat has nowhere to go if you turn off the engine and the fan...so cylinder heads can get so hot the metal starts to soften with no cooling air just after stopping.. and softened heads can crack ..
    But dont run it with no oil pressure/cooling fan..
     
  3. PIE

    PIE

    The cam had gone all the way down and the throttle stop had ridden over, so it was ticking over even lower, Good ideia in the short term I will speed up the idle, I think that the lights were flickering cos it was ticking over so slow it was on the verge of stallingI have a spare 30 pict I will have a look for that roll pin.
     
  4. mikedjames

    mikedjames Supporter

    It shouldnt quite be touching the cam when its warmed up, so it will need the air volume and mixture screws set so it idles with the throttle lever screw as they say 5 thousandths of an inch or a fag paper off the cam when the choke heater is fully warm.
     
  5. PIE

    PIE

    Its a 30 pict one screw SP carb, you adjust the idle with the stop, there is no seperate post emissions system, best single Solex carb IMHO I have been temped to put them on TP engines with an adapter in the past.
     
  6. mikedjames

    mikedjames Supporter

    Explains why the cam going over the top is such a problem with that type then. That might be another reason for not using them apart from probably running a bit lean on a 1600 TP..
     
  7. PIE

    PIE

    Its a 1500 sp engine, I have not had time to check the roll pin situation but it makes sense it should have one
     
  8. Should look like this.
    And the starting is most likely the hot start problem usually cured with a starter relay.
    IMG_4053.JPG
     
    snotty likes this.
  9. PIE

    PIE

    Thanks Bigherb, I hoped you would show up, I thought you would have some idea, Im not sure the hot start would cure it as its a brand new loom, Im off out noe to see if that pin is in place xx
     
  10. PIE

    PIE

    No roll pin!!
     
  11. It is still a long run of wiring and possibly high resistance in the ignition switch. The actuall problem is high resistance in the starter brushes it needs battery voltage to punch through it, like when you shorted the starter.
     
    PIE and snotty like this.
  12. PIE

    PIE

    I think the starter was in some way heat related, its been fine since, I took it out for a test run and noted that it was the exhaust that was hot, pulled the vac pipe and blocked it and it died, checked the timing and it was about 15 after, so well retarded, I reset it to 0 plugged and now it runs great, just can't imagine how it ran so far out ????????
     
  13. mikedjames

    mikedjames Supporter

    Still a bit strange. Unless your pulley is off, that should read either 7 BTDC at idle with hoses off and blocked, or 30 BTDC at high RPM.
    0 degrees is neither correct for USA DVDA vacuum retard, nor normal SVDA and centrifugal only distributors.

    Your engine will run better and maybe cooler .

    You may have to slow down the idle once you set the advance to 7 degrees, as the distributor starts advancing around 1000rpm, so it nay be a case of going round a couple of iterations of timing, tweak air flow and so on.
     
  14. But it is for a 1600 single port, 1500 single port can be 10 deg BTDC or 7.5 BTDC depending on engine.
     
  15. mikedjames

    mikedjames Supporter

    Sorry, thinking TP..

    Despite the cam timing being mostly the same for 1300-1600 engines...
    20190804_083430.jpg

    The timing settings are all over the place based on different distributor curves.


    20190804_083223.jpg

    20190804_084036.jpg
     
  16. PIE

    PIE

    The dizzy is a 111 905 205T {its sad that I know that off the top of me head} its an SVSA carb so 0 at tick over pulled off and plugged
     
    Last edited: Aug 6, 2019
  17. PIE

    PIE

    SOOOO, its manifested itself,,, Cut out like the ignition was switched off!! checked and the dizzy shaft was not turning, 4-5 mm of vertical play caused the dog to pull out, pushed back in and it went, not before I removed the dizzy and put the timing right out, but I am going to put another thread about that in a minute, got me home and its getting a refurb!!! thanks @Bigherb and @mikedjames for the advise xx
     
  18. Most likely the fibre washers have broken up and gone awol. They can be replaced.
    DSCN1014 640.jpg
     
  19. PIE

    PIE

    Not a lot of sideways play in the shaft but a quick google has indicated that vertical movement does throw timing all over the place, it also mentions dwell but I have never been able to understand that.
     
  20. Last edited: Aug 6, 2019

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