Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

help needed with vespa super

Discussion in 'Technical and Troubleshooting Torque' started by tom007, Jan 31, 2006.

  1. i have a vespa super 150 (1965) with a delorto 20/20 carb.....otherwise stock. I have just noticed that when i rev it out in 3rd or 4th gear, it stutters. Seems like a fuel delivery problem. I've checked the plug and its a brown colour so i don't think its that. Otherwise when idling or cruising, its ok- it only stutters under full throttle, full load. If i back off, it'll recover again in a few seconds till its fine.

    If its a fuel problem, would putting in a bigger tank to carby fuel pipe solve it? At the moment its just got some pissy clear plastic tubing.

    Could it be the fuel? Its been sitting for about 2 weeks.

    This problem has only just surfaced.

    Any help would be appreciated.


  2. Tom, welcome the forum, and there's lots of scooter expertise here, and general mechanical too, I'm sure someone will solve old girl's problem.....
  3. thanks hornet600.....good to be here.

    Yeah, this problem just popped up.....got me confused!
  4. Hey great bike!

    and yeah welcome to the forum.

    I'm not as technically minded as anyone here, so i'll leave the tips up to them.

    And stick around after you've fixed your problem, it's always good to have more scooter riders here.
  5. Yup you got probs with the carby.

    Drop float bowl and clean it out make sure the main Jet is not blocked with water / muck blow it out with compressed air and make sure its clean

    check the needle / seat and make sure its clean.

    Main jet and needle only come in from 1/2 to full throttle.

    The pissy bit of plastic fuel line has been on every laverda / ducati / moto guzzi since time began get some new stuff from moto one in oakleigh , I know they have it in stock.

    Has somebody put an in line filter on it ?? check/replace it at the same time.

    Also where the fuel line enters the body of the carb there should be a little round casting with a bolt through it and the barb for the fuel line runs out at 90 deg to the face . remove it and there should be a little round filter disc sitting in there full of muck just waiting for you to fix it

    Good luck classic scoot there dude :cool:
  6. Thanks heaps....i'll check all that stuff. The thing is, i only just put that carby in! It was brand new. I guess it still may have got some crud in it somewhere.

    thanks again,
  7. Now where getting some where have you restored it ???

    The tank on them (under seat ) will have rusted it is 30 years old after all put a small in line filter to catch dust from painting/rust particles etc in and try that.

    Does the points backplate have the condensor riverted on (the italians where famous for it) have you replaced it ???? spark could also be affected if its spent a long time sitting idle and new points installed gapped and checked ????

    Just some other pointers i would suggest
  8. i bought it restored but changed the carby because the one on it was new but was an asian cheapy and the casting was really shitty.....it leaked fuel- must have been warped because i couldn'y stop it leaking. I rebuilt it twice and ended up getting a new one.

    I think you're right- it may have got some gunk from the fuel tank because initially, it was ok. Its just started playing up but only up in the high to full throttle range.

    I'll go through the carby this weekend- there may just be some thing floating around in there and blocking the jet upon full 'suction' (not a technical term!)

    Nice little bike....i can only get it up to about 80km/h at most. Fresh engine still breaking it in so maybe it'll get better. Its burning well though....plug chop after some high rev riging was a chocolate brown. Idling is a little black but i guess it seems like the perfect middle ground.

    thanks for the helpful posts- great forum!