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Thread: Starting problems, please help

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    Junior Member ouhappydays's Avatar
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    Default Starting problems, please help

    Hi guys, just need a little advice here. I've just fitted a new OBR 30.5 race ported top end + stuffed 2mm crank, with reed to my 5b recently. I've successfully run the motor in, heat cycles, 1/4, 1/2 and the other day, full throttle. My problem is, I really battle starting it. To the point where I bought a roto start, because my arm was getting nackered lol. I seem to have to turn the motor far too long before I actually get it started. Once it starts, then she seems to run fine. I thought it might be flooding, and yes I did find the plug to be wet, dried it, and it started quicker. I'm not familia with having a reed, so not sure if it needs different setting.
    Don't mess with my Bajahahaha

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    Baja GEEK! Baja5b-SS's Avatar
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    If your starting the proper way then your plug should not be wet at all, I'm guessing your engine needs a tad leaning in the HSP.
    TBH I have never had any engine problems, and mine seems to start within a few pulls.
    Just hang fire for more info from more people in the know.
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    You are giving it a bit of choke first?

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    Senior Member Jim the Cosmic Goth's Avatar
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    Quote Originally Posted by Baja5b-SS View Post
    If your starting the proper way then your plug should not be wet at all, I'm guessing your engine needs a tad leaning in the HSP.
    Surely you mean the Low Speed Needle???


    Which carb is being used

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    Junior Member ouhappydays's Avatar
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    I'm using the 990 Walbro, so no choke.
    Don't mess with my Bajahahaha

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    Baja-Forum Maniac llazaru's Avatar
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    Sounds like your flooding it as 5b ss has mentioned above, dont know if carb needle settings are same as stock zen/cy 1& half high 1& quarter low, but find them out and set needles. does sound like to rich H setting, have you checked for air leaks

  7. #7
    Junior Member ouhappydays's Avatar
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    Checking for leaks, by tightening the bolts running through carbs, yes I've checked them
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    Senior Member Jim the Cosmic Goth's Avatar
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    how is the compression overall?

    have you checked the little hole in the cyl head, gasket and carb are all lined up correctly?

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    Junior Member ouhappydays's Avatar
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    The compression seems to be good, hence why I bought the roto start, battled starting with the rope start.
    Don't mess with my Bajahahaha

  10. #10
    Senior Member Jim the Cosmic Goth's Avatar
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    does it start okay with the Roto? or do you still have same problem

    I set my OBR up with a quite high compression and it was a pig to start sometimes. found the stock pull start just to short, changed to a killerRC stainless cable which was longer and indestructable made starting alot easier for me.

  11. #11
    Junior Member ouhappydays's Avatar
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    It still battles to start, even with the roto, takes a min or two with my drill to start. My 26cc didn't have that problem lol
    Don't mess with my Bajahahaha

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    Junior Member ouhappydays's Avatar
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    My mate helped me put it all together, he knows his story like, as I say, it does eventually start and run ok, but just takes a while to get there
    Don't mess with my Bajahahaha

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    Baja GEEK! Baja5b-SS's Avatar
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    Quote Originally Posted by Jim the Cosmic Goth View Post
    Surely you mean the Low Speed Needle???


    Which carb is being used
    No I mean the high speed needle, this controls the amount of fuel the engine gets.
    If he's started it with just a few pumps of the primer and the spark plug is wet, then its getting to much fuel.
    CNC milled carbon fibre/Aluminium baja/losi parts stock, modified and custom.





  14. #14
    Baja GEEK! Baja5b-SS's Avatar
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    Quote Originally Posted by ouhappydays View Post
    My mate helped me put it all together, he knows his story like, as I say, it does eventually start and run ok, but just takes a while to get there
    When it does start does it idle ok, is the idle same when its just started or does it drop a lot when warmed up.
    Also once started does it run ok for a full tank, sounds to me still as running to rich.
    I think I have the same top head as your self, and once mine was run in I had to lean the lSN a tad and the HSN about half a turn.
    CNC milled carbon fibre/Aluminium baja/losi parts stock, modified and custom.





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    Junior Member ouhappydays's Avatar
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    Yeah, but have you got a reed valve? There will be a difference in performance with my reed, as it takes a bit to open up, and a bit before the revs drop down again. As I said, it runs fine, idles normal, but drops to a normal rev after a few secs
    Don't mess with my Bajahahaha

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    Baja GEEK! Baja5b-SS's Avatar
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    No reed on mine but the principles of tuning are the same, to much fuel to rich.
    CNC milled carbon fibre/Aluminium baja/losi parts stock, modified and custom.





  17. #17
    Junior Member ouhappydays's Avatar
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    I know mate, I'm familia with tuning the high and low screws. Maybe I'll take the reed off, and see how it performs, take it from there. I was hopping someone on these forums had a reed valve as well, to advise me like. Thanks mate
    Don't mess with my Bajahahaha

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    Baja-Forum Maniac Corbs10's Avatar
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    try putting a rattle top over the air filter (might need cutting down you want about an inch of air filter showing) then try it should try and start then take the cap off then it should start ok

  19. #19
    Junior Member ouhappydays's Avatar
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    Don't know what you mean by a rattle top lol
    Don't mess with my Bajahahaha

  20. #20
    Senior Member Jim the Cosmic Goth's Avatar
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    he means the lid from a spray paint.

    Never thought of this before, but it's a brilliant idea

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