Silent pro, can't find restrictor

Hey all, I brought the latest tecnigas silent pro, and there seems to be no visible restrictor, but I have read there maybe one in the silencer, does anyone know how true this is and how to remove it?

 

They are normally right in the opening of the pipe. If its not there then its not fitted with one. They have tape over the opening when its fitted too.

 

But wait, isnt the silent pro a 2t pipe.

 

Nah bro they definitely make a handful of 4t models. The thing is I will need to find a different 4t exhaust, one better suited toward 90cc, I tho k the 50cc model silent pro is only good go to 70cc, but I have measured the exhaust bore in the new head ( 19mm) which seems about the same as the inner dimension of the silent pro, so maybe it will be okay. The tip of the muffler on the tsp is very small though I understand a little how exhausts work and once gases are cooled down they consume less area so it exhaust can be designed like that to keep the flow at velocity but, I was wondering if I might be better off trying to not a 125cc exhaust to fit my bike, its going to have a lot of mods after today.

52.40mm Bore and Head
A9 Camshaft
Racing crankshaft
Irridium plug
Racing high output coil
Racing CDI
24mm carb 102# main jet
24mm smooth intake manifold
Jetflow manifold spacer
Unrestricted modded airbox
Silent pro exhaust
Malossi multivar
7g Dr pulleys
Shortened boss
Fly clutch and bell
Torque control
Torque driver upgrade
1500 spring
Kevlar belt
17% Primary gear increase
New hoses and breathers
Fast flow filters
Harder rear shock
Custom vented rear brake shoes
Upgraded kick start
All new gaskets and seals
Castrol power rs 4t oil 10/40w
80/90 Malossi sport gear oil

Is there anything missing, that anyone can notice?

 

You can buy downpipes for those motors. Like prebent, then get a slip on silencer for the end of it. You can get away with quite a short pipe on these little motors without burning your valve seats.
I highly recommend reading the book "4 stroke tuning in theory and practice" think its bell?
I do a lot of motor builds.
In practice its better for power to have a rough intake tract and smooth exhaust. If you work on drag racing engines you would see what I mean.
I love doing engines, I could talk about this all day

 

Oooh have you checked out motogaga yet? So much 4 stroke tuning stuff in asia. They make them sooo fast.

 

Scuba biker, thanks for you're quick and concise answers they're helping me, I have another question.

On my engine a single piston four stroke, how is the compression stroke decided, I.e the fly wheel and crank shaft have to make 2 identical rotations for 4 strokes correct? I'm guessing this is the job of the camshaft? 1 full flywheel/crankshaft rotation is half a cam shaft rotation correct?

To try and make myself a little clearer, 1 rotation from top dead centre on the flywheel, will be exactly the same as the next rotation, so I'm guessing with 1 full flywheel rotation the cam chain will turn the cam only half a rotation right? If not every rotation would would be the same I.e 2 stroke?

This is the 1st 4 stroke I've taken apart I used to play with my dirt bike engines a long time ago.

But if on a 4 stroke we have one ignition per 4 strokes, as opposed to 2 ignitions per 4 strokes on a 2 striker, wouldn't the same displacement 4 stroke engine have to the much higher than a stroke for similar output power?

 

Yeah, you have that right. I think. It burns my brain to work out ratios.
Most 4 strokes use wasted spark. So it sparks every time its at the top.
The way the 2 engine types make power is very different. Less moving parts in 2t, so it can rev higher, making more power at the higher range, yet a 4 stroke has a sort of inertia in the engine from the moving parts, at higher rpm a 4t will create valve float, where the valves limit the amount the engine can spin.
I can go on forever about this sort of stuff.
Like I said, get that book, it explains the basics and goes into details.

 

I was right, its bell who is the author. I had it on pdf a time ago. I might be able to find it again

 

what would all these mods cost !