Exhaust de-restricting - removing weld points -what to use?

[CometGeezer]

Hi there

I had a bash at 'eroding' or grinding down 3 welding points (about as big as a screw head) on the cylinder of my exhaust.

I was told to use a "dremel" so i went to B&Q and asked them 'can i have a dremel capable of grinding down/out weld points on an exhaust?'

so i get this dremel bit for £2.95 take it home and begin drilling... all that started to grind down was the dremel itself!

The idea was to grind the weld points down then remove the tube which is inside, there may have been screws so i'd also have to unscrew them (duh!).

Can anyone tell me exactly what drill bit or dremel thingy I would need to do this?

Cheers,

Matt.

[G]

Is this on a NSR?

Some small sized, decent metal drill bets for a start. Get at least a couple of each. Cheap ones may only last for a couple of holes or less.
You want to start with about 2mm, then increase the size to increase the hole. It's the first drill bit you use that will take the brunt of it, so gets spares of this one.

You can get grinding bits for normal drills.. I got a couple that were about an inch in diameter that with a bit of effort got a weld smoothed out on my dr600 frame.

[Kickstart]

Hi

The Dremel grinding bits come in a tube of about 50, and break regularly (heavy duty ones are better), but you will need a Dremel to use them.

All the best

Keith
____________________
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[CometGeezer]

Hi G: not an NSR no, it's a Comet Hysung 125 - thanks for the tips

I've got a normal drill - bloody powerful thing it is! - think i'll stick to the grinding bits for normal drills.

Cheers

Matt

[iCraig]

Seeing as the Hyosung comet is a 4 stroke 125, I very much doubt that it is restricted.

As they don't produce enough power as to warrant any sort of restrictions I'm afraid.

[G]

That's what I was afraid of. As we doubt it's restricted, are you sure you're not drilling something required to hold teh exhaust together .

Might be worth getting some pictures and posting them up.

[mr jamez]

You can get an angle grinder from homebase for £11.99 then the grinding disc is about £2.50, Why fath about with anything else when you can just brutalise it!

As above dremel bits are pretty useless without a dremel! and drill bits can be expensive if you are buying a few decent ones

I assume you are just getting the metal sleeve off that is round the exhaust or something?

[G]

When done on the NSR, the welds are inside the exhaust, where it connects to the cylinder. Therfore an angle grinder would be a tad overkill .

[mr jamez]

Any excuse to use it really

I am not too sure what he is actualy doing to the exhaust though, so thought I would suggest it.

[G]

It would have to include cutting the exhaust in half if you were using the angle grinder ...
This is what it's like on the nsr:
https://www.nsr125.com/exhaust2.jpg

[mr jamez]

Ah I see, I thought he was messing around with the other end of the exhaust. So yeah, forget the angle grinder idea

[G]

He may well be, which may explain how a 4 stroke 125 is 'restricted' .

[Project9928]

G the end of a comet exhaust has three welds that hold a smaller pipe in place, aparently if you take this tube out its supposed to derestrict it. I don't know if this works or not? I won't be doing it to mine as I want it standard and unchanged because I will be selling soon SV650 here I come

[G]

Personally, I doubt it will make much difference, apart from to the sound.

Restrictions to power are rarely at the very end of the exhaust, I would expect something would need to be done to the fueling if the exhaust was significantly changed.

[Project9928]

To be honest I think its good as it is, Comets accelorate quite well and can get to 70 no prob so I don't really see the point in trying derestrict it?

[G]

[CometGeezer]

in my case it's moreso for the sound than anything else.

[Ade067]

Did you buy the bike new? Because if you mess around with it like that and anything goes wrong you will probably invalidate you're warranty and for the amount of speed you would gain (probably nothing) is it ever worth it??

I bought a brand new Comet 125 last may and so far its been perfect all bar a couple silly things I put right and touch wood I've not had to have any warranty work done on it yet,mine is completely standard just as it was when it came out of the tin!

I love riding mine and you get loads of people coming up to ya and asking if its really just a 125...take it to a bike meet in the summer and you'll see what I mean!!

[CometGeezer]

hi Ade067

no i bought it off ebay - i love riding mine too it's such a great feeling of freedom... you're probably right tho, best to get a bigger CC bike if i'm looking for increased speed.

Cheers

Matt.

[Project9928]