Crankcase full of petrol - type 4 engine, twin solex

Discussion in 'Mech Tech' started by jim mcglynn, Jan 31, 2023.

  1. As per title. I took the plugs out and span the engine , and fuel spurted out of nearside front cylinder (closest to passenger).

    Assume it will be sticky float needle or sunk float, so will take carb off and do a mini rebuild.

    But, before I start, is it possible that something else could cause it ?

    Thanks in advance.

    Jim



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  2. Little Nellie

    Little Nellie Supporter

    I had this, but with Webers and was due to a float needle that had worn very quickly. As you ask, maybe another reason. But the fuel cut off has sorted everything for me. Takes the worry away
     
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  3. Marty SmartyCat

    Marty SmartyCat Supporter

    Obvious one for you Jim, but you want to consider (REALLY REALLY consider) full oil and filter change before you try and restart the engine.
     
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  4. Thanks chaps. And yep, just done a full oil and filter change. . Will do another in a few weeks.

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  5. Little Nellie

    Little Nellie Supporter

    £14. By Valtek

    619CB42B-AEA5-4E84-9157-7EEF2D26C84F.png
     
    Last edited: Jan 31, 2023
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  6. Also if you have the original mechanical fuel pump, that's supposed to prevent this happening. Mine leaked through to the carbs though not so dramatically as to fill the engine. In desperation I also fitted one of those fuel cut offs. It's pretty reliable.
     
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  7. Dubs

    Dubs Sponsor supporter extraordinaire

  8. There on eBay
     
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  9. Thanks folks. I had one of these cut off solenoids , but removed it about 3 years ago cos it caused some fuel starvation issues. Going to try avoiding that for now, but may try one again at some point.
     
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  10. Little Nellie

    Little Nellie Supporter

    Yep, eBay
     
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  11. Mr Apollo

    Mr Apollo Supporter

    Sorry to hijack the thread slightly. I have one of these in the van, a PO fitted it just before an electric fuel pump. The black lever that moves between 'on' and 'off', is that to bypass the solenoid? When it is covering the 'off' as in the image, does that mean the fuel will only flow when there's power to the solenoid, or is it vice versa? When we first got the van the lever was halfway between the two, would have been like that for at least 18 months before I noticed, would that have limited the fuel flow?
     
  12. Chrisd

    Chrisd Supporter

    It may depend which type you have, but on mine, the power switched the flow. So if it started closed it would open with power applied, but if it started open my switch would turn off with power applied...guess how I found that one out :)
     
  13. Little Nellie

    Little Nellie Supporter

    My understanding is that if the solenoid fails you can flip the leaver and this gives open regardless of electrical signal. So only used in the event of solenoid failure
     
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  14. mikedjames

    mikedjames Supporter

    I doubt the solenoid was really the cause of fuel starvation, the hole through it is quite large. It is advisable to put a filter before the solenoid to stop dirt interfering with its operation.

    Try another solenoid valve or a check valve before you DESTROY YOUR ENGINE !!!!!

    The Solex needle valves do stick with dirt in them - one at Techenders once filled the engine overnight after completing 100 mile trip to the campsite. .
    Maybe your fuel tank is a bit rusty/dirty inside.

    Another possible sticky solenoid trick was one I saw where the rubber tipped valve would be sucked down so hard by the suction produced by the return spring lifting the diaphragm in the mechanical fuel pump mechanism as the valve closed with the engine stopping, that it would stay closed until either more voltage was applied or you let off the vacuum in the fuel pipe.
     
    Last edited: Jan 31, 2023
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  15. Little Nellie

    Little Nellie Supporter

    So instructions as below - so should be set to OFF if unit is working

    6B1B31BA-8B79-43BD-92C5-09378E5ADE3B.png 836E4A76-7AD5-4794-A59E-EC3CB69F065B.png
     
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  16. I miss your old avatar.:(
     
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  17. i prefer your old one also
     
  18. He should change it back...
     
    Last edited: Feb 3, 2023

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