Changes

272 bytes added ,  20:26, 26 September 2017
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two different stock exhausts
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*Carburetor options include the Dellorto (or really Dell'Orto) SHA 15.15 and its army of clones (direct fit on stock intake but add an o-ring; read the wiki on this carb); Mikuni VM18 or VM20 or VM24 with the aid of an MLM intake.  PW80 carbs and Amal 15mm carburetors are also rumored to work.  Pwonly.com offers 19mm and 21mm carburetors with intake that will likely work on the qt50 as well.  The MLM 24mm spigot style intake also allows for OKO and pwk style carbs in addition to the Mikuni VM24 carburetor.   
 
*Carburetor options include the Dellorto (or really Dell'Orto) SHA 15.15 and its army of clones (direct fit on stock intake but add an o-ring; read the wiki on this carb); Mikuni VM18 or VM20 or VM24 with the aid of an MLM intake.  PW80 carbs and Amal 15mm carburetors are also rumored to work.  Pwonly.com offers 19mm and 21mm carburetors with intake that will likely work on the qt50 as well.  The MLM 24mm spigot style intake also allows for OKO and pwk style carbs in addition to the Mikuni VM24 carburetor.   
 
*Any talk of bigger carburetors or larger top ends has to include air filters.  Any 28 or 29mm air filter is most likely an improvement over the stock air box (although many have resorted to drilling speed holes into the stock air box).  The K&N RC-2540 Universal Clamp-On Air Filter is a good but expensive choice.  Do not use the entire oil package that comes with it to oil the filter.  Half the package or less is plenty.  Cone mesh air filters of the 28-29mm variety are plentiful and cheap on ebay or amazon and equally effective.
 
*Any talk of bigger carburetors or larger top ends has to include air filters.  Any 28 or 29mm air filter is most likely an improvement over the stock air box (although many have resorted to drilling speed holes into the stock air box).  The K&N RC-2540 Universal Clamp-On Air Filter is a good but expensive choice.  Do not use the entire oil package that comes with it to oil the filter.  Half the package or less is plenty.  Cone mesh air filters of the 28-29mm variety are plentiful and cheap on ebay or amazon and equally effective.
*Exhaust options include the MLM People's Sidebleed pipe; the tomos A35 biturbo pipe (will require slight modification to flange and additional bracket for mounting); and, if you can weld or have access to someone who can, anything you can weld on to the stock header.  Again, a performance exhaust will call for a larger main jet in the carburetor.   
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*Exhaust options include the MLM People's Sidebleed pipe; the tomos A35 biturbo pipe (will require slight modification to flange and additional bracket for mounting); and, if you can weld or have access to someone who can, anything you can weld on to the stock header.  Again, a performance exhaust will call for a larger main jet in the carburetor.  Yamaha used two different stock exhausts on the qt50.  One had an "S" shaped header and the other had a much straighter header.  Although unlikely that any significant difference exists, the straighter version contributed more to performance than the "S" shaped version.   
 
*The addition of a performance exhaust, bigger top end or both has the detrimental effect of killing acceleration from a stop or slow speed.  Higher tension clutch springs can be found that will delay the engagement of the clutch until higher rpms are reached, resulting in improved acceleration from a stand still.   
 
*The addition of a performance exhaust, bigger top end or both has the detrimental effect of killing acceleration from a stop or slow speed.  Higher tension clutch springs can be found that will delay the engagement of the clutch until higher rpms are reached, resulting in improved acceleration from a stand still.   
 
*An oil injector block off plug can be found if you choose to go to premixed fuel.  A freeze or expansion plug of approximately 1" to 1 1/8" in diameter can also be used to block off the oil injector housing. Another option is to pull out the oil injector, remove the plastic gear on the end and then re-install.  
 
*An oil injector block off plug can be found if you choose to go to premixed fuel.  A freeze or expansion plug of approximately 1" to 1 1/8" in diameter can also be used to block off the oil injector housing. Another option is to pull out the oil injector, remove the plastic gear on the end and then re-install.  
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