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Im looking at replacing the exhaust and dont know where to start, I plan on having the bike for a long time and am just looking for a better and louder sounding exhaust without losing performance.
Also am looking at painting the gray mud guard over the front wheel, want it matte black or just black in general as the gray looks shit in my opinion. Dont know where to start with type of paint or how to go about painting without it cracking. Saw a post saying to use enamel paint?
Sorry in advance, I am not very mechanically minded but I do try and am very willing to learn. If you could reply in simple terms that would be very helpful, thankyou in advance!
 

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2008 YZF-R125 (180cc)
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Im looking at replacing the exhaust and dont know where to start, I plan on having the bike for a long time and am just looking for a better and louder sounding exhaust without losing performance.
I can't comment specifically on the gen3s having not got one but on the early bikes replacing the exhaust is actually pretty straightforward even if you're not too experienced. I guess the later bikes will maybe have exhausts specific to them (don't know), but don't assume an exhaust for an earlier model woudl fit, but there do look to be gen3 systems available.. e.g:


you can see from the pics there's not a lot of bolt holes - there's a hanger, and maybe a strap type thing round the silencer if it still has that like the old bikes, or maybe that hanger in the middle replaces that. On an old bike you'd maybe run into rusy exhaust studs which can be majorly problematic if they break off but on a 2020 that really shouldn't be an issue unless it's been parked in a lake since then.

There's a bung halfway down the pipe for an o2 sensor - idk if that's the stock gen3 placement for it or whether it's for aftermarket ones but if there's one there on the oem pipe, it'll need screwing into that bung.. but there's not really much more to it than that. New exhaust gasket needed too as it is (was, presumably still is) a crush gasket so is single-use.


Dont know where to start with type of paint or how to go about painting without it cracking. Saw a post saying to use enamel paint?
you can do a fairly decent job with just spray cans but the paint goes on pretty thin and isn't super durable, so especially on a thing that's having mud and grit flung at it all the time it'll wear quicker than you'd probably like.

I'd say if you did a decent job with cans, you might need to top up the paint on the mudguard every 6 mo to a year or so. I guess it depends on how many coats, how often you clean your mudguard and how much crap you ride through. With a week's road grime on the underlying colour might not really even matter.

Whatever paint you go with you'll need to make sure the paint has something to grip on, so will need to sand down the mudguard which is best done with it removed from the bike. Get some 600 grit wet and dry paper and a little bowl with some water and a little squirt of fairy liquid in it, cut a sheet into 3 strips, fold them over themsevles a couple of times and put one in the water to soak for a few mins, and then start roughening (and smoothing where there's bumps) the surface till it feels smooth to your fingers and you can verify visually that all areas have been roughened a bit (it just needs to be nice and evenly matte, not scored/scratched. You'll need to rinse it off and let it dry to see which bits you've missed so this is something to be done with a bit of patience

The wet and dry paper used wet should be quite gentle but is still cuts well when wet and doesn't wear out as quick as when it's used dry. You can go back and dip it in the water periodically to rinse the paper and improve sanding. Take the opportunity to remove and small plastic casting seams or imperfections too. Don't rely on the paint to hide anything, though matte black is about the most forgiving there is for scratches and imperfections.

this mudguard for mine was done using exactly that method and used one 500ml can of red paint. You could probably use half that much paint with matte black as wouldn't need so many coats but keep the rest for touch-ups. That was from bare black plastic with no primer or anything, just careful sanding and quite a few thin coats of that red. (primer would have been wise re coverage in retrospect hence so many coats but not really needed for going to matte black). I'd say rear mudguard is also a fairly high-wear position so is comparable and this has been in place for 2 years now and whilst the gloss has definitely faded it still doesn't actually have any chips or flaking.

second pic is a year later you can just see from the reflections in the top bit that it's still got a decent shine to it when cleaned:

Plant Tree Bumper Wood Vehicle
Wheel Tire Fuel tank Automotive tire Automotive lighting



you might want to give it a few coats then once it's properly dry (like a few hours in the sun or overnight) give it just the lightest possible rub rown with the rough side of a fresh kitchen sponge which is great for removing tiny imperfections between coats. then more coats, repeat till perfect or you get bored :). If you have some, apply a bit of polish when finished to disperse water and protect the finish. Too few coats and it'll wear off too quick. too many and it'll crack/flake so once it looks good and nice and even and you've done maybe 3-5 coats, step away and let it dry properly and then you should be good to go.

This is not a quick process if you want perfection but matte black is probably the easiest option to paint and you could probably get away with just a quick rub down and a few coats, leave it to dry overnight and then put it back on the bike next day and just see how long that looks good, accepting that it'll probably need topping up at some point. 6mo or so might be acceptable for the reduced work involved and future touch ups could potentially even be done on the bike with improvised masking to protect surrounding components. Matte black blends really easily too (old paint with new) so it's probably the colour with the highest chance of doing a great-looking job with minimal input/expertise.

Most underrated piece of painting equipment imho - If possible get a few "tack rags" (e.g. 3) off ebay. They're not expensive and are mesh/cloths which have a sort of waxy coating and pick up dust and suchlike, and if you get into the habit of wiping the panel down with one just before painting, you'll minimise the amount of unwanted guests and particles in your paint. keep the cloth somewhere reasonably clean and dust free and it'll last several uses too. If a bug lands on your paint as soon as you finish your coat (which happens often), leave them be..they'll either fly away or be sorted by the rough sponge between-coats smoothing. trying to remove them from wet paint will make it worse.

also any paint is pretty toxic so ideally spray outdoors or make sure to have good ventilation and a mask (e.g. if in an open garage). If you can smell it you're breathing it.
 

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*if you can't remove the mudguard easily (on the gen1 the front wheel needs to come off which is a mission by itself), then you could maybe carefully sand it and paint it in situ but you'd need to be thorough with masking it up. You can use masking tape and plastic shopping bags to cover larger areas. If doing on the bike probably all that'll be feasible will be a quick sand and a couple of coats and see how it holds up.
 
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