moped petrol problem

sparks

30/07/2009 at 23:08

Hi guys.

my son's moped been having problems with cutting out after riding a couple of miles.

tried the obvious new plug and cap, checked a spark ok so attention now on petrol as does seem like petrol starvation all seemed ok but still cuts out after a few miles so give to dealer as only done 1000 miles from new. is Derbi sm by the way, and dealer can't find anything wrong. gets it back and he cuts out again but this time by chance i pop the petrol cap and big hiss of air which i know does happen but this time the bike starts straight away.

Any ideas what would cause this and what should i do as driving me mad.

edgey biker

30/07/2009 at 23:28

sounds like there is no air vent to the petrol cap? try getting a new 1 or unclogging the hole if there was 1. or if its just a plastic cap you can ty putting a tiny holy in the top.

xr125... BECAUSE ITS FUN

twoeyedbob

31/07/2009 at 08:09

Aye,sounds like your vents blocked,mibe a hose kinked sumwhere.

edgey biker

31/07/2009 at 14:53

let us know how it turned out

xr125... BECAUSE ITS FUN

sparks

31/07/2009 at 18:28

I was thinking that but i'm led to believe that as there are two hoses from the tank to the carb and no fuel tap i think it is vacuum fed so no air vent required but both hoses are only 9inch long so no kinks i can see. unless a blockage in the carb is the thing.

The thing is driving me mad, as i keep telling myself its only a moped so not rocket science spark, petrol, air job done but its only after about a mile it cuts out so starting to look at float chamber perhaps not filling up as a moped would do about a mile on just whats in the carb i reckon. but will keep looking,

cheers for all your replies though your all thinking the same as me which does help.

Sparks

Ginner

31/07/2009 at 18:34

ride it with the petrol cap open and see if it cuts out!! If its only done 1000 miles is it still ubnder warranty?? If so tell the dealer to sort it pronto

twoeyedbob

31/07/2009 at 18:37

You got a manual?
Or try to google a fiche/diagram of the fuel
System.
Have you had the tank off?or is it not that simples?
I hate intermittent faults,major pain in the ass.

sparks

06/08/2009 at 01:56

well edgey, you were bang on the money. Could not find it at first. Yes hole on cap was blocked. Also found a little water in tank and carb. But now runs fine. Many thanks

edgey biker

06/08/2009 at 01:58

woo, it happned with my ts (probs because of the age and the fact it was sat a while)

xr125... BECAUSE ITS FUN

tappy

06/08/2009 at 16:48

Other likely cause is a sticking float valve in the carb. Next time it cuts out kick the carb a sharp knock. If you don't know where the carb is, get someone else to sort it out for you

arrrf.

sparks

08/08/2009 at 18:15

tappy wrote (see)

Other likely cause is a sticking float valve in the carb. Next time it cuts out kick the carb a sharp knock. If you don't know where the carb is, get someone else to sort it out for you .

That was what i was starting to think it was at first but is a new bike so did not want to take apart myself due to the warranty, but now worth remembering.

The_moped_boy

13/07/2010 at 11:32

asacly this has happened to my bike i have a CPI POPCORN and that was stood for a long time a year and 1/2 but then i got it up and running and working good but when i finely got on the road it don't wont to work it s the same problem half way to the shop ( cut out ) half way back home ( cut out ) so i got the compressor and blew all the carb, air box and cleaned the petrol tank and filtered the petrol but now it started good and ran for a few more miles but got home and now will not start i have been told by my mums boy friend that it could be vacuum tap that is attached to the petrol tank underneath to feed the carb.....

but now im looking for a new 1 as its driving me mad.

Evile

13/07/2010 at 19:46

Vacuum system or not, you have to replace the displaced fuel somehow, Im rather impressed the tank is air tight enough in the first place to vacuum lock the fuel pipe

From alternators to zip-ties, Wemoto's got it, and we'll send it anywhere.

VFR Owners club, monstering young whippersnappers on R1s. *

*with 3 piece luggage, the wife and her dog.

jon man

16/02/2012 at 00:36

hi ihave a problem with my moped when u accelarate it chugs makes power and loses power and some times stalls and when u take of then u lay off the accelarator it also stalls i have had a new spark plug cleaned carb and jets out and refreshed fuel it still is ent going properly can any one help please thanks