Derestriction Help

Discussion in 'General Tuning' started by oliver8, Mar 14, 2012.

  1. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Cheers ramo.
    I never said i was just going to pick and choose the rollers and jets I simply said I will be upping the jet size to a 58 and lighter rollers.
    The rollers come with the malossi which is a bonus.
    The exhaust doesnt specify what jet size to use but I have been told to up the jet size to atleast a 58 or 60 as the exhaust will run better with the bike if this is done.
     
  2. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Just an update.
    The jet has been changed to a 60 from the original 53.
    I have also fitted a malossi MHR exhaust (I believe it is called).
    I took the exhaust baffle out briefly to hear it and it was stupid loud, I'd definitely get a few coppers givin me a odd look, so stuck it back in.
    I haven changed the rollers yet but will be doing so on Saturday or Sunday.
    Overall I get 50mph out of it. The first 10mph are very slow but the rest is
    stupid quick. I'm guessing this is a result Of the exhaust revving very high and having heavy weights in it so will see what it's like wih lighter rollers.

    But top end looks good just got to play around with the rollers now to hopefully make the bike move better from a stand still as its very slow of the start almost as if it struggles to find first gear.

    Oliver,
     
  3. Duggiedan

    Duggiedan Piaggio zip 50cc

    Messages:
    538
    Rides:
    Piaggio Zip
    53 jet with malossi exhaust? :O put a size 56 in or you will end up overheating
     
  4. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Duggiedan:
    Hi mate, you have misunderstood me.
    The original jet was a 53 I'm now running a size 60 with the malossi exhaust. Touch wood it seems Alright.

    Have you got any idea why my bike is very slow 0 to 10mph? Is it cause of the rollers being to heavy for the exhaust if so then panic over as that's going to change as of this weekend.

    Cheers,
    Oliver
     
    Duggiedan likes this.
  5. FiddyRox

    FiddyRox Well-Known Member

    Messages:
    1,112
    Rides:
    Aerox, CRF450, YZ125
    I would get some stiffer clutch springs, they make the revs go right into the powerband, instead of having to wait for the revs to clime up.

    This is usually the case with a sports exhaust, as it moves the power higher up into the rev range.
     
  6. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Clutch springs sounds about right.
    The fuel air mixture seems about right but seems a bit rich in low rpms which is probs cause I'm at full throttle when trying to take off.
    Will put lighter rollers in and new clutch springs.

    Found the clutch springs I need, I thought it might of been something to do with a pilot jet (I've heard) but will try the clutch springs.
     
  7. Duggiedan

    Duggiedan Piaggio zip 50cc

    Messages:
    538
    Rides:
    Piaggio Zip
    i am running standard clutch springs with 70s ect and myn sets off like a treat id drop roller weight a little
     
  8. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Duggiedan:
    Will be fitting lighter rollers hopefully this week and clutch springs when I get them.

    See how it turns out.
     
  9. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Have now fitted the clutch springs and the 0-5mph acceleration is brilliant.
    I put the lighter rollers in and ended up keeping the stock rollers as the lighter ones reduced top end rapidly.

    I do however have another Problem, the bike acceleration to 5mph is rapid regardless of other goings on.
    But after that the bike poodles along at walking pace up to 20mph then BANG the power kicks in.
    I have found a temperorary solution, if I put the bike on the stand and rev the bike until it makes a whining noise or reaches max revs an then brake gently and then ride off the bike has great acceleration no matter what the revs/speed and behaves as it should.
    However I would like to ideally jump on the bike and ride off Without having to rev the crap out of it first.
    Any help is greatly appreciated.

    For those just joining the thread and wanting to help, I have already put a:
    Size 60 jet on it from a stock 53
    A malossi racing air filter
    A malossi MHR exhaust
    Malossi racing clutch springs
    Tried lighter rollers but was worse so kept stock
    Removed variator washer

    Again any solutions to this problem are greatly appreciated as i don't like having to rev the bike to get it working before I ride away.

    Cheers,
    Oliver
     
  10. wedgie

    wedgie Member

    Messages:
    222
    Rides:
    Mk 1 Zip SP
    Did you put the malossi filter on after you jetted for the exhaust? and you'd have to jet to suit the filter as well?
     
    Duggiedan likes this.
  11. Jeff Munro

    Jeff Munro Member

    Messages:
    87
    Is that malossi filter a open air filter? if it is then your bike must be running stupidly lean?
     
  12. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    The filter and jet were put on at the same time and the filter has been tried with the stock 53 (too lean) a 58 jet and a 60, overall the 60 was the best by not much different from the 58 to be honest.
    The filter is not a open filter and is a filter sponge within a air box.
    I believe I am running a fairly good air/fuel.

    What I don't understand is why the bike goes really slow unless it is revved to max revs, bought down to idle speed and then ridden normally.
    It's almost like it needs to be warmed up to work which I understand some performance parts require but, the difference between the bike when it's cold and when it's been revved to the max are extraordinarily different.
     
  13. Jeff Munro

    Jeff Munro Member

    Messages:
    87
    Well bikes need to be warmed up before use, Im no expert but your max revs solution seems to me like its defo a carb issue.
     
  14. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Guess I'll tweak around with the carb a bit more then.
    I have a brass plate air restriction on the carb so might remove that and also been told to raise the high needle a bit.

    But any other ideas are welcome

    Cheers,
     
  15. Mr Bizzle

    Mr Bizzle Active Member

    Messages:
    947
    Rides:
    04 Aerox 70 stage 6
    Personaly I would have changed the roller weights before the clutch springs. Lighter rollers allow the engine to rev higher into the power band before taking up the drive. Stiffer clutch springs mean that the rear driveset has to be spinning faster before the clutch engages the drum and drives the rear wheel. If you've got heavy weights in the variator then it will be fully engaged at lower revs (below your powerband) and your clutch will engage before you hit the power band. Resulting in poor acceleration until the engine hits the powerband
    A 50 with a sports pipe usually doesn't need the clutch springs changed.
    I would put the original clutch springs back on, and put in the lighter variator weights. If the weights are too light it will just rev it's nuts off and go nowhere , too heavy and they open before you meet your powerband.
    The variators jois to hold the revs steady in power band to allow the engine to run at maximum power.
    Have a look at the pedparts blog it explains how it all works.
     
  16. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Tweaked around with the carb and I've got the bike running 99% perfect just +\- a size in roller and the bike should be good.
    Amazing how a little twist and turn in the carb can make such a difference, also increased airflow by changing air filter.

    I don't want to do it cause it's too loud but, by removing the fabrics type baffle in my exhaust could this:
    Increase top end?
    Bugger the bikes acceleration up due to shifting the power band?
    Would this increase airflow making the bike run leaner (heard this is possible)?
    I've heard this can damage the engine due to no back pressure or something is this true?

    Just curious.
    Cheers,
     
  17. FiddyRox

    FiddyRox Well-Known Member

    Messages:
    1,112
    Rides:
    Aerox, CRF450, YZ125
    The system was designed to run without the baffle so it will be more powerful. Yes it will lean out so you will need a slightly bigger jet.
     
  18. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Thanks FiddyRox, i really want to do it but, I know I'll get pulled over for excessive noise which will the lead to them finding out my bikes been tuned up.
    So probs not a good idea.
    But thanks again,
     
  19. FiddyRox

    FiddyRox Well-Known Member

    Messages:
    1,112
    Rides:
    Aerox, CRF450, YZ125
    Yeah man it's all about compromise, with the baffle in you can go pretty quick and not gett any unwanted attention
     
  20. oliver8

    oliver8 Member

    Messages:
    41
    Rides:
    Aprilia Sportcity 50
    Another update.
    I got the bike running almost perfect with just a few issues in the low rev area.
    However in a attempt to improve things I haven't changed much, but I have still got a recurring problem. ( needs to go lighter on weights I think)

    If I start the bike up and just go or even let it idle for a bit and then go, the acceleration throughout the rev range is stupid quick, (to the point where it really pulls away.....QUICK)
    However after about 10mins of riding and once the bike has warmed up this changes.
    When the bike has warned up it goes from rapid acceleration throughout to really slow from stand still up to 10mph (almost walking pace) and then really rapid up to it's max speed.

    Why is this?

    Is it a clutch/variator problem?
    Or maybe a carb problem?

    I doubt the carb problem as I have recently made the bike run leaner as I was running way to rich.

    Anyway any help will be really welcome.

    Thanks,
    Oliver
     

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