125-200cc Husqvarna 125 sm - Tuning?

Hello,

Never knew this forum existed! I'm from Brussels, Belgium and its hard to find good forums about Husqvarna because they're not so common around here!

Anyway, I have a Husqvarna 125 sm, and I'm thinking about changing the exhaust pipe. I want to buy a second hand full SPES line.

-Does anybody know if this is a good type of brand?
-Does this type of pipe gives more mid-end or top-end performance?
-Will it actually bring a big difference in power, or should I also change the carbu?

The stock carburettor is a Dell'orto PHPH 28


Plus, I also had a problem with the power valve system, one of the valves had broken of its rod, and got hit a couple times by the piston...
Should I also replace the other valve? It's in good condition, but the bike has about 12 000 km (7500 miles) and since the other valve broke out of wear, it's probably the smartest thing to do...
The problem is that these valves are expensive, 80 € (about 90 $) a piece!
Are there any aftermarket brands that fabricate these parts, cause I can only find original husky parts!

Grtz.

Hi
There arent many on this site with sm bikes. There is a guy in the UK with a modded one and his bike is in the pictures of your two strokes bikes . Maybe he can guide you . He has changed just about everything but from what I can gather is it is hard to get much power increase from that version - the motor is a lot different to the WR . ( what power do they have stock 15 hp ?)
Id either leave it alone or replace complete motor with a used WR motor if possilbe
Good luck

Okay, thanks for the reply!

Can you tell me what's the difference between the WR engine and mine?
I thought it was the same apart from a different cylinder head! (and of course a bigger carbu and unrestricted exhaust)

Stock they do have 15 hp.

There must be more to it than that - have to mix your own oil , Ignition .
I dont really know much about it but Ive seen a post where the head, carb and exhaust was changed and only made 20 hp on dyno . Yet Ive seen one with supposedly 30 hp on dyno . PM the guy with the SM in UK ...OK (PS if exhaust restricts it it may be worthwhile but may make it noisier)

PM is on its way!

In the meanwhile I found a guy who's willing to sell his '03 CR block (with Mikuni carbu and HGS exhaust) for a reasonable prize.

I just don't know if certain parts will fit on my '99 block?
Like the cylinder and cylinder-head? Would you know this?