Author Topic: No archive I can find [To pump or not to pump}  (Read 190 times)

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Offline RdsOnly

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No archive I can find [To pump or not to pump}
« on: October 20, 2021, 09:29:30 AM »
To Pump 2t or Not to pump [Premix]
OK
What is you R series pump?
#1 Did you know the 1st Yamaha 2stroke race bikes[YD1]USA race Catolina had a pump on them?
   They took them off- and pre mixed, later proven on the 80cc Japanese bike.

A pump is a mechanical precision made instrument- tuning fork please Yamaha logo. yes they are kind of complicated but m=not realy when you understand what they do.
Yamaha was 1st, Kawasaki, Bridgestone, the others.
  Why did Manufacturers install a complicated device to meter oil for a 2 stroke?
 Due to years of testing, they found a need for a graduated mechanical pump to optimize use and operation of 2 strokes. in the 1960 you can find vehicles in the 150cc range going 60,000 mile before rebuild. Dependable??? YES

So you question your 1970's oil pump- not dependable  What happened?
  If you recall in 1980- late fuel change no longer you could get 98 oct-100 oct supreme. Now 95 oct was supreme, mid grade= 90 oct, low was around 87oct.
  1970's 2 and 4 stroke were designed to run on that years fuel.

 So you fill your R5 with supreme 1980  that is now  90oct/86me you over oil and must adjust your pump. I worked at motorcycle shops at that time.

 Most guys did nothing might have re jetted and eat their top end [less lead in fuel].
Good for us we did a lot of top ends, shyster said it's your pump- get rid of it..

Not true but thousand shucked their pumps and premixed 22:1 castor based oil, lost of fouled plug. 
2 strokes are finicky I want a 4 stroke- 2t bikes were cheap late 80's

So your non mechanical OLD man told you premix F*** the pump.. You as all good kids believe what is herd.
 Young 1972 you are 14 yrd you have seen a lot of Hondas some Hodakas, not many Kawasaki's and Yamaha's But when you saw a Kawy go zipping by OMFG.
 I want one, then a Yamaha R5 zipps by the boggy of the start kawy....

OK well I like mechanical stuff... a Bilge pump is real similar to an oil pump in a car.
  So I am a young teen peddling around watching fast bike ziping around me as well as the Honda 80/90/120 scooters.

Back to Oil pumps... OMFG
To pump or not to pump today in 2000 era Yes pump we are lazy for GOD sake. FUel sucks even worse now.
OK- pump design
idle- 100:1- max 18:1
WFO [Wide Fucken Open] 18:1 some 20:1 kawi
 SO you premix 32:1 where is that mix optimum-1/2 throttle top gear 4krpm-5krpm....
Do not do long pulls in 5th or 6th gear WFO
   I have seen all kinds of seiziers on piston is this and air leak of timing- Pliiiiissss
4 corner is lack of oil..
Under piston will show to advanced timing or to lean- long pulls.
 Timing is piston crown dents, to ring land melted... Plug will show SPECKLES piston on plug ground.EGT= 13000+ if you have one. Timing and air leak- air leak is though out throttle  of line to WFO.


This is way to long I have to stop here- cliff hanger,,,,,

JT
more ask questions. maybe I will answer I hope I will.


 






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