Rodney68
Well-Known Member
LOL sounds like the way to go matching coloured bikes twins LOL
my new/used Yamaha PW50 thread
- Thread starter my67xr
- Start date
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- 1981 2t 2 stroke pw 32 to 1 4x4 50cc big bore carbon fibre reeds custom expansion chamber gytr handguards high comp shaved head home made muffler irc tyres kids mx leather seatcover mikuni 15mm big jets new stickers decal polished plastics ported intake premix pw50 peewee 50 scratched plastics shaved head y zinger yamaha minibike
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One step closer to his YZ?
Rodney68
Well-Known Member
LOL thats it Hillz will not be long and before you know it he will want to ride the YZ.
my67xr
Miniriders Legend and Master Spanner Spinning Mode
look what you can get for the PW50 too, it's got your name on it Hillz
http://www.gumtree.com.au/s-ad/well...t-system-for-yamaha-pw50-not-bike-/1017193248
there are also things like Boyesen reeds, bigger carbys, 60cc barrel and head conversions etc etc
http://www.gumtree.com.au/s-ad/well...t-system-for-yamaha-pw50-not-bike-/1017193248
there are also things like Boyesen reeds, bigger carbys, 60cc barrel and head conversions etc etc
Hillz
WC ST Killa
deff need one of those!
my67xr
Miniriders Legend and Master Spanner Spinning Mode
http://www.ebay.com/sch/i.html?_odk...3.m570.l1313.TR0.TRC0&_nkw=pw50+race&_sacat=0
FMF even have 2 different mufflers available for them.
FMF even have 2 different mufflers available for them.
my67xr
Miniriders Legend and Master Spanner Spinning Mode
i have just been down and picked up the freshly bored barrel, it now measures 40.5, instead of 40.25 ,
the PW is now a true 50cc, actually a 50.5 cc to be exact.
it looks pretty sweet, time to start reassembling it now
i have borrowed my sons phone while he is out, so the pics should come up a fair bit better too.
you can see my quick port work, i opened up the exhaust a bit, and straightened the runners,
same with the intake, took a bit out of the corners, and any casting dags etc, and a couple of mm's of the bottom of the runner (short return) to help it flow a bit smoother.
exhaust port,
and the inlet port,
the 2x side ports didn't look to bad, so i have left them as is for the time being
cheers, craig
the PW is now a true 50cc, actually a 50.5 cc to be exact.
it looks pretty sweet, time to start reassembling it now
i have borrowed my sons phone while he is out, so the pics should come up a fair bit better too.
you can see my quick port work, i opened up the exhaust a bit, and straightened the runners,
same with the intake, took a bit out of the corners, and any casting dags etc, and a couple of mm's of the bottom of the runner (short return) to help it flow a bit smoother.
exhaust port,
and the inlet port,
the 2x side ports didn't look to bad, so i have left them as is for the time being
cheers, craig
Rodney68
Well-Known Member
Top job on the ports Craig it will be good to hear how it goes now.
Port n polished PW, cool stuff 
Hillz
WC ST Killa
i have just been down and picked up the freshly bored barrel, it now measures 40.5, instead of 40.25 ,
the PW is now a true 50cc, actually a 50.5 cc to be exact.
it looks pretty sweet, time to start reassembling it now
i have borrowed my sons phone while he is out, so the pics should come up a fair bit better too.
you can see my quick port work, i opened up the exhaust a bit, and straightened the runners,
same with the intake, took a bit out of the corners, and any casting dags etc, and a couple of mm's of the bottom of the runner (short return) to help it flow a bit smoother.
exhaust port,
and the inlet port,
the 2x side ports didn't look to bad, so i have left them as is for the time being
cheers, craig
i dont think 50.50cc is correct, they are standard at 49cc 40mm, .5mm over size would not be that much of a cc gain
Hillz
WC ST Killa
just checked.. it would be exactly 50cc now at 40.50mm
my67xr
Miniriders Legend and Master Spanner Spinning Mode
guess it depends on what calculator you use
40.5mm bore, 39.2 stroke
http://www.bgsoflex.com/cgi-bin/dis...m=40.5&osize=0.0&stroke=39.2&mode=Millimeters
40.5mm bore, 39.2 stroke
http://www.bgsoflex.com/cgi-bin/dis...m=40.5&osize=0.0&stroke=39.2&mode=Millimeters
Hillz
WC ST Killa
lets say its 50.25cc haha
my67xr
Miniriders Legend and Master Spanner Spinning Mode
yeah, they are 49.3cc standard
my67xr
Miniriders Legend and Master Spanner Spinning Mode
i have been trying to suss the compression ratio for it,
the standard motor has a 6-1 compression ratio.
since i have shaved the head 1mm, im guessing it now has around 10.5-1,
i'll be running it on a premium mix with Shell advance 2 stroke semi synthetic oil at 40-1 ,
not that i use anything else.
the standard motor has a 6-1 compression ratio.
since i have shaved the head 1mm, im guessing it now has around 10.5-1,
i'll be running it on a premium mix with Shell advance 2 stroke semi synthetic oil at 40-1 ,
not that i use anything else.
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my67xr
Miniriders Legend and Master Spanner Spinning Mode
my67xr
Miniriders Legend and Master Spanner Spinning Mode
i've just had a go at burning the carbon/oil from the expansion chamber, it's got a bit in there.....
but there's too much smoke for today, i'll have to wait for a windy day so all the neighbours dont choke.
here are some of the loose bits that came out when i tapped it with a hammer.
a couple of the bigger bits are almost 2cm across, easy to see how they block up and restrict the flow.
but there's too much smoke for today, i'll have to wait for a windy day so all the neighbours dont choke.
here are some of the loose bits that came out when i tapped it with a hammer.
a couple of the bigger bits are almost 2cm across, easy to see how they block up and restrict the flow.
my67xr
Miniriders Legend and Master Spanner Spinning Mode
my67xr
Miniriders Legend and Master Spanner Spinning Mode
i am having a play around with some scrap steel atm,
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my67xr
Miniriders Legend and Master Spanner Spinning Mode
i put the PWs' engine back together yesterday arvo,
no drama's there, gave it a few kick's and she came to life,
it chuffed a bit of oily smoke out for the first minute due to the oil i put in the bore, rings, piston and bearings etc
and then started running clean, it definately has some compression compared to before.
the rattly piston noise has gone too.
the choke cable needs replacing, was a bit dry and stiff, and the inner cable is now a 2 piece.
i might have something i can replace it with and adapt it to work.
the exhausts' sound has changed a little too, most likely due to the part clean out it's had.
no drama's there, gave it a few kick's and she came to life,
it chuffed a bit of oily smoke out for the first minute due to the oil i put in the bore, rings, piston and bearings etc
and then started running clean, it definately has some compression compared to before.
the rattly piston noise has gone too.
the choke cable needs replacing, was a bit dry and stiff, and the inner cable is now a 2 piece.
i might have something i can replace it with and adapt it to work.
the exhausts' sound has changed a little too, most likely due to the part clean out it's had.
