Vespa 50cc hole in exhaust

[mipak]

24-9-2017

Hi ...

I bought my moped from new in May 2009 and so far, it only has about 4,500 kilometers on the clock ... I live on an island, thus the low mileage.  With the exception of the rear tyre and a new battery both in 2015, there have been no other replacement parts.

A short while ago, a small hole appeared in a small pipe projecting outward from the exhaust ... the increased exhaust noise is slight.  This pipe is no more than about 2 inches long and about ½ an inch in diameter.  One end is open where it joins the main larger diameter exhaust and the other end is closed so in effect, this tiny pipe has an input but no output.

What I'd like to do is to remove this pipe and make a proper seal around the main exhaust pipe to secure the newly-made hole.

Seems to me that this small pipe is totally surplus to requirements and doesn't do anything unless some kind person who uses this forum and knows Vespers better than I do.

Incidentially, the hole in the small pipe is no more that half the size in diameter of a British 5 penny piece.

Have tried to attach a drawing to show the above problem but the site has refused it saying only a max. of 1M is permitted yet my jpg format drawing is only 75Kb.   Oh well ...  can't attach it ... sorry!!
 
Any and all suggestions to this exhaust problem will be more than welcome.

My thanks in advance  ... Michael.

[citydaz]

buy a new exhaust?

[mijapxman]

mipak is the exta tube similar to this? px one 👇

www.ebay.co.uk/itm/Exhaust-LML-Vespa-PX80-150-Sprint-/401068718914?hash=item5d618efb42:g:hXQAAOSwqeZZdfOc

If my memory serves me right, I think it's called a resonator pipe?,I believe it's a way of restricting performance for legal reasons, you could cut it off and weld the hole shut
Or squash it as close to the main down pipe as possible, be aware it may? affect your carb settings and make your
engine run lean, not sure but worth checking.

All the best.

Mij☺

[mipak]

Thank you for the exhaust link but sadly, this is not suitable for my bike which is the LX50 model.  It annoys me that I'm unable to add an attachment to my post because if I could, all would become clear.

However, the following link shows the complete LX50 exhaust and this little 2 inch long pipe is very noticible by its absence ... take a look ...

www.ebay.co.uk/itm/Vespa-LX-50cc-2T-Complete-Exhaust-System-/272643669679

from where it screws onto the cylinder block, move your eye down around the curve of the pipe until it straightns and up and carries on into the silencer itself.  'My' little pipe is almost halfway along the straight part and more or less under the bike as opposed to it being more easily accessible at the side or below the exhaust pipe.

Think you also mentioned de-restriction ... I've never known it to be a mechanical modification but rather an electrical one  like re-routing part of the wiring circuit but you could be right in modifiying part of the exhaust.  This is also mentioned in the above link.  My current exhaust was assembled at the factory and if I had no other choice other than to buy a completely new exhaust (which would never have had a little pipe attached in the first place), I can only assume that by cutting off the little pipe on my existing exhaust and welding across the hole, will have achieved the same objective and at much less cost.

In the absence of my attachment, below is my attempt of 'drawing' out the little pipe problem.  The 'X' marks the location of the hole.
                                                                               
                                                                                                      l
                                                                                                      l -------------------)     
                                                                                                       < cyclinder              )
                                                                                                      l -------------)         l                                                 (--------------X-----l                        l                    l         l
                                               (      (----------------l                                            l         l
                         ---------------)      (-----------------------------------------------)          l
                                                                                                                                  )     
                         < silencer                                                                                          )
                         -------------------------------------------------------------------------

Hope it's understandable.
Michael.

[henri]

a blob of exhaust paste an a jubilee clip would be my answer . H

[ianmartin40]

there are details of how to insert pictures on the Introduce yourself page, it is the first post from the moderator this may help.
Ian

[mijapxman]

Mipak, the link I posted was only to get an idea if the small tube on it looked familiar, as their is no such thing as a Px 50 or px moped, to my knowledge 😉.

The answer to what the small tube does seems to be answered in the link you posted, if you read the product description,
It has a section beginning with "note:". which appears to describe it.
Mij☺