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Engine stuttering

Discussion in 'Fuel System & Electrics' started by Ignats, Apr 14, 2019.

  1. Ignats

    Ignats Member

    Messages:
    91
    Location:
    Merimbula
    Hi Everyone
    Took kombi out yesterday for a couple of test drives
    Seems to struggle under load
    A bit of background info
    76 1916 plugs new and gapped
    Twin carbs freshly rebuilt by Andrew
    New dizzy and timing set.
    Seems to rev fine while stationary but when I drive down the road and give it a squirt it seems to splutter more so as I head up a small incline
    I would like to sort this myself as it’s all part of the curve of Kombi ownership
    I think I will replace HT Leads just to eliminate those then check fuel pressure which should be ?
    I have a clear fuel filter fitted in the line that doesn’t get more than about 1/2full it’s laying horizontal is this ok
    Can anyone recommend a reasonabley priced fuel ,vacuum tester
    I relize I will get bombarded with info as to what to look at and will do my best to make my Kombi run sweet
    Thanks in advance let the help begin
    Cheers Ignats
     
    Last edited: Apr 14, 2019
  2. Barry

    Barry Well-Known Member

    Messages:
    3,395
    Location:
    Abbotsford NSW
    What carbs do you have?
    Do you know what jetting
    What linkage?
    Do you have a synchometer?

    Making sure you have your carbs synced and the linkage set up properly in very important in getting a twin carbed motor

    The problems you have I would suggest carb set up
     
  3. Ignats

    Ignats Member

    Messages:
    91
    Location:
    Merimbula
    Solex Brosol
    H32/34 PDSI
    I think Andrew(1500 king) said from a wagon
    Linkage is same as type 3 wagon
    Yes I have synchometer
    Jetting is as per Andrew’s rebuild
     
  4. Barry

    Barry Well-Known Member

    Messages:
    3,395
    Location:
    Abbotsford NSW
    Ok - that all seems ok but you sure the linkage is opening up equally?
    Not opening one carb first?
     
  5. Ignats

    Ignats Member

    Messages:
    91
    Location:
    Merimbula
    Will check this again when I get home but should be ok
    Setting the mixture is where I think I might be going wrong
     
  6. Barry

    Barry Well-Known Member

    Messages:
    3,395
    Location:
    Abbotsford NSW
  7. Ignats

    Ignats Member

    Messages:
    91
    Location:
    Merimbula
    It appears there’s not a lot out there on running these puppies
    It’s all about PDSIT and there different
     
    Last edited: Apr 14, 2019
  8. Ignats

    Ignats Member

    Messages:
    91
    Location:
    Merimbula
    Hi Barry
    Yes you were right about the carbs being out of sync.
    I’ve got them sync.on the gauge at 8 idle is smooth and seems to rev ok.
    Was keen to test drive so did that but no improvement was possibly slightly worse.
    Throttle linkage seems ok for adjustment.
    So as to adjusting these I’ve gone with disconnected linkage sync carbs with idle screw so there exactly the same.
    Reconnect linkage and adjust so both working in sync.
    Have just left the air fuel mixture screw back to starting point as per Andrew’s instructions.
    Still going to replace HT Leads will pick some up tomorrow.
    Just to rule that out and I’ll know I’ve done them.
    Fuel delivery is still something I’d like to know is right to
    Will try leads first
    Might have to ask Andrew
    Don’t like to bother him when he’s at work with my inexperience with these things
    I’ll get there eventually
    If anyone else wants to chuck in there 2cents worth feel free
    Cheers Ignats
     
  9. Barry

    Barry Well-Known Member

    Messages:
    3,395
    Location:
    Abbotsford NSW
    if you are talking one of these meters 8 is WAY too high

    upload_2019-4-15_19-14-9.png

    Should be 3 at the most.
    Been a while since I set my DRLAs and IDF's but it wasnt 8

    As for the linkage - you need to refit with a zero effect at rest
    Feather touch the cam or whatever pulls the 2 arms and while watching both carbs at once (that's the tricky bit!) make sure they crack exactly at the same time.
    You will be surprised how the linkages twist and distort and what you thought was ok at rest is well out as throttle is applied
     
  10. cbus

    cbus Well-Known Member

    Messages:
    11,600
    Location:
    sunshine coast
    Wire core leads don't usually give issues as long as connected.
    More likely plugs.
    Do a test by removing a cup at a time and observing rev drop on each cylinder.
    Andrews settings should be good so don't muck with them other than ensuring balance till other things checked.
    A spare spark plug put into each lead when disconnected will show strength of spark.
    Obviously fit with engine off .
    Earth body of plug to fan shroud.

    Check for carbon track inside dissy cap.
     
  11. Barry

    Barry Well-Known Member

    Messages:
    3,395
    Location:
    Abbotsford NSW
    Also make sure of a nice strong white / blue spark

    not a soft orange glow
     
  12. Ignats

    Ignats Member

    Messages:
    91
    Location:
    Merimbula
    Yep that’s the meter I’ll try and get it as low as I can
    Will spend a lot more time on linkage to get same same
    Plugs are all new and set will check spark quality
    Dizzy is also new
     
  13. tintop

    tintop Well-Known Member

    Messages:
    422
    Location:
    Canberra
    while you had the timing light connected did you make sure your dizzy is advancing the spark correctly?
     
  14. Ignats

    Ignats Member

    Messages:
    91
    Location:
    Merimbula
    To quote Pauline
    Please explain
     
  15. Barry

    Barry Well-Known Member

    Messages:
    3,395
    Location:
    Abbotsford NSW
    Think he means that at idle your timing is at 10-ish degrees

    At say 3,000 you should be 32-ish degrees

    BTW - idle should be 900-ish
     
  16. Ignats

    Ignats Member

    Messages:
    91
    Location:
    Merimbula
    Idle timing about 7
    3000 is about 28ish
    Idle 850 ish
     
  17. Barry

    Barry Well-Known Member

    Messages:
    3,395
    Location:
    Abbotsford NSW
    OK - them is good numbers
    28 is a bit low though - i would try bumping that 5 degrees to see what happens

    Will be interested what happens when you pull a plug lead at idle.
    Can you hear the revs drop for each cylinder?

    I'm still leaning towards linkage.
    They are touchy buggers
     
  18. cbus

    cbus Well-Known Member

    Messages:
    11,600
    Location:
    sunshine coast
    What grade fuel.
    95 can run extra advance.
    I know others disagree but I run 32 mechanical at max which is usually 3000rpm or a bit higher.

    What dissy
    ?

    A rebuild by Andrew will be graphed correctly but most Chinese are crap .
    Sticky and bad advance curves
    This can be roughly checked if suspect.
     
  19. Ignats

    Ignats Member

    Messages:
    91
    Location:
    Merimbula
    Fuel 95
    Dizzy is a SVDA Accuspark best I could do at the time
    Will try the for mentioned advance to 32 and do the plug lead checks recheck linkage
    Will let you know how I go
    Thanks for the help
     
    Barry likes this.
  20. cbus

    cbus Well-Known Member

    Messages:
    11,600
    Location:
    sunshine coast
    Just observe it with a timing light for a smooth and quick advance .
    A check of advance at a couple of points as well.
    Maybe 1500/2000/2500.
     

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