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live'n the struggle
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Joined: Sept 8, 2015 23:49:33 GMT -5
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Post by phil on Sept 14, 2015 18:30:47 GMT -5
hi, I'm new here this is my first thread.
Relatively new to scooters as well but I'm looking forward to learning more.
I have a 50cc gy6 qmb Chinese scooter that I bought used. I enjoyed riding it for about three months three years ago. It lost compression and sat on my back porch for a long time. I Got a rebuild kit 80cc big bore conversion, and I got the 20mm carburetor to go with it.
here's my questions
1) what are the torque specs for the head-nuts for an 80cc conversion?(and also the bolts that go on the side of the head next to the timing chain?)
2) what type of oil should I use now?
(I live in central Florida where it doesn't get cold much of the time but we are approaching winter now)
thanks for your input, and I'm glad to be a new member of a forum like this where I can learn more
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Post by JerryScript on Sept 14, 2015 19:34:48 GMT -5
I have a 50mm (82cc) BBK on a Znen Q50 (yellow one below), I do not torque to specs (been working on small engines long enough to have a good feel for it) so I'll let someone else chime in on that.
As for oil, any decent 10w30 or 10w40 will be fine. I've been running mine on dollar store oil for 2 years now as an experiment, no issues at all, but I do change it every 300 miles in summer (Vegas heat) and 500 miles in the winter.
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Post by florida on Sept 29, 2015 15:33:36 GMT -5
Hello phil, Welcome to itstheride.boards.net! I too am in Central Fl. I ride a Znen Corp. 50cc scoot. Check out my thread, its my first build. itistheride.boards.net/thread/8301/gmw-coil-filter-tachomter-installedThis is the $21 craftsman torque wrench I used. It is highly reccomended that you use a beam type torque wrench rather than a "click type". You can break a bolt much more easily with a click type than a Beam Type torque wrench. pic :  Torque Specs for the head nuts are 15 ft lbs. The bolts that are on the side of the head should be tightened AFTER you torque the head bolts to 12lbs to be on the safe side. ( I torqued my head bolts to 15 ft lbs and on the last one I felt the bolt start to strip a little bit inside the engine case as my beam style torque wrench reached 15lbs. DO NOT use a "click style" torque wrench. They are notorious for being inacurate on the inexpensive models and also your head studs are probaly cheapo Chinese made steel. ) 2) I changed my oil 3 or 4 times in the first 1000 miles after 100cc bbk conversion and made sure to rummage in the used oil for any metal shavings from the "breaking in" process of a new Bbk. I never did find any metal pieces in the used oil, leading me to belive that how I was told to break in the engine from itstheride.boards.net forum was accurate information. ****i rode my new 100cc scoot at varying throttle positions. I drove the scoot at 15 mph for periods of time ( I live in a congested area. The causeways in Tampa Bay are congested at times and thats how I was able to drive at such a low speed.) I drove at speeds hovering around 25mph. I approached full throttle for periods of time during the break in process but never twisted the throttle to full throttle or w.o.t. ( wide open throttle). ** My znen scoot went 39mph top speed with 6500 miles on it and was very slow when taking off from a traffic light and over bridges. Now after the conversion it has much more low end torque and Im not a hazard in traffic. Its reccomended that you use 15w 40 motor oil during the first 1000 miles. I did my first oil change at 100 miles, the next at 400 miles, the one after that at 750 miles and at 1000 miles I started to use 10w40. Thats 3 oil changes. Use 15w 40 for 100 miles and at the 1000 mile mark switch to 10w 40 oil. I personally use Walmart motor oil. I have been changing my oil every 700 miles. Thread on breaking in bbk. itistheride.boards.net/thread/6738/break |
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