Silent pro, can't find restrictor

Discussion in 'Scooter Tuning' started by Scootboy87, Nov 12, 2018.

  1. Scootboy87

    Scootboy87 New Member

    Messages:
    13
    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?
     
  2. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,632
    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.
     
  3. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,632
    But wait, isnt the silent pro a 2t pipe.
     
  4. Scootboy87

    Scootboy87 New Member

    Messages:
    13
    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?
     
    Last edited: Nov 12, 2018
  5. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,632
    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
     
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  6. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,632
    Oooh have you checked out motogaga yet? So much 4 stroke tuning stuff in asia. They make them sooo fast.
     
  7. Scootboy87

    Scootboy87 New Member

    Messages:
    13
    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?
     
    Last edited: Nov 12, 2018
  8. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,632
    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.
     
  9. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,632
    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
     
  10. steve w hebburn

    steve w hebburn New Member

    Messages:
    9
    Rides:
    1999 kymco zx fever
    what would all these mods cost !
     

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