Typhoon vacuum fuel issue (i think)

Discussion in 'The Workshop' started by Cyberdyne system model101, May 20, 2020.

  1. Cyberdyne system model101

    Cyberdyne system model101 New Member

    Messages:
    4
    Hi friends and thanks for taking the time to look at my post. I have an 09 50cc piaggio typhoon that’s only dome 2000 miles from new which I use only a few times a month just to pop down the shops. I am an old fart of 53 and can’t be bothered to walk it. The bike is 100% bog standard. It broke down a few weeks ago with symptoms of fuel starvation. It would run fine for about 1/4 of a mile then just die. It would not start again until it had been standing for several hours then would go another 1/4 mile and die again (and so on and so on). I thought it was a fuel issue so replaced the vacuum fuel tap but that did not cure the problem. So I went a bit mad and replaced the Battery , Spark plug and carb(with new) as parts are cheap for these. Now it will start sometimes run for a few seconds and stop. I do not know enough about the vacuum fuel delivery to know if I have an issue that I am missing. If I apply a vacuum to the fuel tap then fuel flows ok. But if I fit the vacuum pipe back on the carb and pull off the fuel line and crank the bike over no fuel will flow out the end of the pipe. I have a few questions to ask which are. Does the air filter need to be fitted and have a good seal to the carb for a proper vacuum to be made? I have the bike plastics all off and the seat also which give me good access to the carb etc but I am not refitting the air filter whilst trying to start the bike after new carb fitted etc. Also if I remove the carb and crank the bike should I be able to feel a vacuum if I hold my hand over the inlet manifold (which I have tried and do not feel a vacuum)? And are there any known issues with vacuum problems on these bikes. Apologies for the long post but bear in mind you dealing with an idiot here (lol)
     
  2. MARSH

    MARSH Whooooo!

    Messages:
    3,200
    Rides:
    Piaggio Typhoon
    I'm 54 ! Check reed block, it sit's under the rubber inlet manifold. Make sure reeds are intact. Is the auto choke connected ?
     
  3. The Messenger

    The Messenger Active Member

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    163
    Just to add to Marsh's good advice...

    hold the reed block up to light and look through it at arms length.

    The reeds should be air tight, so if you see any light shining through, then thats an air leak.

    also carefully check your rubber inlet manifold, its common for them to perish and crack causing an air leak.
     
    MARSH likes this.
  4. Cyberdyne system model101

    Cyberdyne system model101 New Member

    Messages:
    4



    Ok guy’s great advice. Yes auto choke is connected (and new) I have already ordered a new inlet manifold but will check the reeds as per your advice. If it turns out that the reeds need replacing can anyone suggest where I can get a set? One other thing there was no gasket between the reed block and the engine...is this normal on these bikes? I thought it strange being reed block is plastic and engine is metal? Anyway I have ordered a manifold gasket set to put in as that eliminates another potential cause.
     
  5. The Messenger

    The Messenger Active Member

    Messages:
    163
    if the reeds arent sealing and they are still intact, then quite often a taper has worn on the end of the reed petals. you can take the reeds off and fit the petals back to front and they seal again. its a free fix worth a try... It doesnt work though if theres chunks missing off the reeds.
     
  6. Cyberdyne system model101

    Cyberdyne system model101 New Member

    Messages:
    4
    OK thanks for that i will have a check tomorrow(as bike at my work place)
     
  7. Sam phantom

    Sam phantom Active Member

    Messages:
    874
    Use thread lock is you remove/replace the reeds!
     
  8. MARSH

    MARSH Whooooo!

    Messages:
    3,200
    Rides:
    Piaggio Typhoon
    If all this fails then theres an old protocol that we use , it's called "sell it me" and don't be a tight arse and buy a new scooter !! :D
    We'll help you to get it sorted. cheers.
     

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