Grandvista / Grand Dink / Bet & Win 250cc Exhaust Rattle & issues...

[mrbios]

Last night my exhaust which started to rattle around 7K miles. cracked half on the highway.  I had ear plugs in and it was a noisy ride home!

Two months ago I use a 7" angle grinder to open the back end of the muffler (part where smoke comes out).  I then saw that I could not remove the parts inside because they were welded from the other end.  Today, I cut open the other end - major surgery.  I found that two welds were not done properly.  Also, a "hot dog" like object got loose and was vibrating and beating up the inside. I removed the "hot dog" and welded the pipe back in and sealed everything back up using a cheap harbor freight MIG / wire welder.  The result is things are nice and quite.  This saved me the cost of spending $270 (tax + shipping) for a new oem exhaust or $300+ for an after market pipe and I like my scoot as quite as possible.  If I want more power I won't waste time with an aftermarket pipe I'll buy and install a 300cc upper cylinder / piston kit for ~ $400.

Also, I removed the chrome trim because it was damaged from the minor crash last December when the city left buckets of sand on my own street at the corner!

Total time of repair including clean up of tools: 3.5 hrs.

TIP: I purchased 1 quart of black barbecue paint at home depot for ~ $10 and used an air sprayer to paint it and it came out great and really lasts.

[mrbios]

Here is the painted exhaust.  After welding it today I will need to repaint it.  I waited 24 hours for it to dry and fully harden before riding the scooter.  It lost the gloss and became a smooth flat black.  No primer needed or recommended. 

TIP: click the actual attachment to download it or open it at full size.

[Rudolf]

Mine had a loose component rattling at the end of the muffler, so i've cut open the muffler and removed the loose plate part. After that i've arc-welded everything back together. The weld i've painted with coal tar to protect against corrosion.

[mrbios]

Mine had a loose component rattling at the end of the muffler, ...

Wow, I never though I would run into someone with the same problem and solution!  Nice work. 

[mrbios]

Wow, I never though I would run into someone with the same problem and solution!  Nice work.

Wow again!  At the dealer (12/2014) last week they had a blue GV250 with a cracked exhaust.  The muffler (fat round part) had completely separated from the exhaust pipe AND the triangular bottom support held on by the largest / longest bolt.  I believe that this is caused by the design of the exhaust where the three bolt holes don't line up properly placing the exhaust in continous tension. 

Also, there was not physical damage or scratches on the exhaust that might have caused the problem. 

[zombie]

Like you said, it's poor welding from the factory. they tend to simply "tack weld" these parts, and the vibration is at it peak back there. It's not the welds that fail but rather the metal on the edges of the welds.

Kudos!

[mrbios]

Like you said, it's poor welding from the factory. they tend to simply "tack weld" these parts, and the vibration is at it peak back there. It's not the welds that fail but rather the metal on the edges of the welds.

Kudos!

Thanks Zombie.  You are right about the welds.  Welds are thick and solid but the vibration give the muffler and it's thin metal a bad case of Rattle-Brain which spreads eventually to the rider BTW (By The Way) my exhaust has started to rattle inside after only 2000 miles.  I'm gonna try to ignore it as long as I can. Kymco should have recalled the part and issued an upgraded exhause.  If I have to repair it I might cut the muffler off and install a motorcycle exhaust.  especially one where I can disconnect the header instead of having to drop the whole exhaust every time I change the rear tire or need to fix a flat. 

[zombie]

That's actually a great idea.

I HATE dealing w/ the exhaust due to the chance of something cracking or leaking every time you move it.

I have a shelf FULL of cracked expansion pipes.

[mrbios]

That's actually a great idea.
I HATE dealing w/ the exhaust due to the chance of something cracking or leaking every time you move it.
I have a shelf FULL of cracked expansion pipes.

When I get around to it I will post pictures.  I've gotten tired of welding the exhaust and having it break in a new place - especially when that new place is inside the muffler or (expansion pipe?)

[zombie]

Some parts or entire machines are just jinxed. If something cracks it is because of an un natural "twist" in it somewhere.

I don't bother any more. I just replace whatever broke vs repair it

[mrbios]

. ...
I don't bother any more. I just replace whatever broke vs repair it

 Did you replace it with an OEM exhaust or aftermarket?

[jayocampo88]

Where would I find this aftermarket exhaust??
I haven't been able to find anything.

Either that, or what would be the best way to go about installing a motorcycle muffler?

[mrbios]

Where would I find this aftermarket exhaust??
I haven't been able to find anything.

Either that, or what would be the best way to go about installing a motorcycle muffler?

I have only found one system for the GV and it was $300 that is why I was considering buying a 4 stroke OEM 250cc dirt bike exhaust off craigslist and cutting the Kymco exhaust near the muffler and probably using part of the old muffler as a base to mount the "new" exhaust muffler to.  Right now I'm still keeping the original OEM exhaust going.