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Post by prodigit on Jan 22, 2013 1:26:57 GMT -5
Most of the Big Bore kits expand on the CC's of a 50cc scooter engine.
50, 63, 72, 75, 80, and even upto 100cc kits are available online.
125 is not, because it's too big for a 50cc scooter.
So I was thinking,
Could I put a 100, or 125cc kit on a 150cc engine?
Benefits:
Engine runs cooler
Engine has better MPG.
You think it's mechanically possible to do this?
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Post by carasdad on Jan 22, 2013 10:02:36 GMT -5
Most of the Big Bore kits expand on the CC's of a 50cc scooter engine. 50, 63, 72, 75, 80, and even upto 100cc kits are available online. 125 is not, because it's too big for a 50cc scooter. So I was thinking, Could I put a 100, or 125cc kit on a 150cc engine? Benefits: Engine runs cooler Engine has better MPG. You think it's mechanically possible to do this? It will work. I have owned 2 Tank Urban Sporty 100cc that I bought and gave to relatives. They are the exact same GY6 150 engine...with the exception being the top end only has a 47.9mm bore. One needed rings and the 100cc parts are not available so I used a 125 top end. Worked great and even the 150 top end fit..but he did not want it that big. Best of luck though finding a 100cc top end for the gy6 150...I looked everywhere with no luck as they only imported 100 of the Tank 100cc scoots. But you can drop a 125 kit in the 150....same engine same stroke etc. |
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Post by h3nry on Jan 22, 2013 11:44:39 GMT -5
Yeah it should be possible, the issue is finding the kit lol
I can get all this for $70 plus shipping. (I think that's a bit high but then again I haven't seen any others prices)
Cylinder Head
(64mm valves)
Cylinder (50mm ID)
Piston (50mm OD)
Wrist Pin
Complete Gaskets Set
Complete Ring Set
Qmb139 Roller Weights,16*13
Oil Pump (42.5mm bolt hole spacing)
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Post by carasdad on Jan 22, 2013 11:56:48 GMT -5
Yeah it should be possible, the issue is finding the kit lol I can get all this for $70 plus shipping. (I think that's a bit high but then again I haven't seen any others prices) Cylinder Head (64mm valves) Cylinder (50mm ID) Piston (50mm OD) Wrist Pin Complete Gaskets Set Complete Ring Set Qmb139 Roller Weights,16*13 Oil Pump (42.5mm bolt hole spacing) Where did you find the 50mm piston/cylinder? Is it one for the QMB139 50cc engines? |
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Post by lovemy2strokes on Jan 22, 2013 11:58:31 GMT -5
You can do a 100, 107,108,110,117,124,149,174,179cc on a GY6 based engine. All these are stock bores from different models. When I get a 110 atv I put a 150 gy6 cylinder and head on them to make them 150s. I always have good 150 gy6 cylinder kits from doing BBKs on peoples scoots.
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Post by lovemy2strokes on Jan 22, 2013 11:59:10 GMT -5
I think even the 90s are the same Ive just never got into one yet as its cheaper to buy a new one than work on it.
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Post by scootnwinn on Jan 22, 2013 13:30:22 GMT -5
By the time you get the kit on the "savings" from increased mpg would have to be astonishing or you are snipping the juevos off that bike for nothing. I wouldn't think it would run any cooler because I'm certain you'll have that thing WFO all the time. I imagine there is a good reason why 100's and 125's are so popular  or are they |
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Post by scootnwinn on Jan 22, 2013 13:33:27 GMT -5
do you think they make a 30cc kit for a 50cc?? Cause I hate horsepower. Sorry I was just having a hard time figuring out how underpowering an already underpowered vehicle would benefit anything... decreasing the power to weight ratio will not increase the mpg
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Post by lovemy2strokes on Jan 22, 2013 14:19:14 GMT -5
I kind of forgot to say the same thing scootn +1 on all the above, itll have to work harder to maintain the same speeds.
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Post by 50cc on Jan 22, 2013 16:39:12 GMT -5
Engine WILL NOT run COOLER with smaller displacement.
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Post by prodigit on Jan 22, 2013 23:57:27 GMT -5
Great for testing.
I do not believe that a 100cc is underpowered. If anything, it has plenty of power to do the regular supermarket trips, and for the occasional highway moments.
If anything, it'd be nice to just compare how it would do against a 150 in MPG's.
It's all about gaining info, not all about the money.
Gaining knowledge, could save someone else, or many others a lot of money (eg: imagine if you find out that a 100cc small bore kit does sip a lot less fuel than a 150, then people could start thinking on mass production.
Usually, finds like these, lead to production lines of new products, so I don't think it's un-valuable information at all! (that is, if it would work)...
Upon which information do you base that your gas mileage goes up when decreasing cylinder size?
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Post by lovemy2strokes on Jan 23, 2013 2:07:49 GMT -5
It comes down to gearing, its geared for the power of a 150 not less. If you change the gearing then fine but your top speed will go down as well. If you try to push tall gears with insufficient power you will get massive amounts of heat and you will use a lot of fuel to struggle to maintain.
Its the same thing that happens when putting gears on the 50cc bikes with out major work done to the engine.
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Post by prodigit on Jan 23, 2013 19:25:39 GMT -5
The gearing of 150cc's usually the variator is maxed around 40MPH.
The power of an engine has very little to do with gearing on a cvt.
Even a 100cc will easily make 40mph.
More than likely, a 150cc might be able to get to 7k rpm (say that'd be ~65MPH).
The 100cc might only be able to get to 6k RPM, (say that'd be ~55MPH); but that would easily be adjusted with lighter rollers (to increase top RPM, and only let the belt hit the top of the variator around the top rpm's).
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Post by lovemy2strokes on Jan 23, 2013 20:42:49 GMT -5
Ha where do you get this info from, I ride with the cover off and at 60 the variator isnt maxed out. Youre talking out your rear. The power of an engine is CRUCIAL with a cvt, no power no over drive.
Im not even going to keep reading this thread.
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Post by prodigit on Jan 23, 2013 21:57:48 GMT -5
If you are going to read it or not, that's your own choice.
You could learn a thing or two here.
If your variator isn't maxed out when the engine makes max rpm's, that means the bike is tuned for better MPG's, and the rollers are too heavy.
Ideally, the CVT should be maxed out at ~75-80% of RPM's, leaving you some extra to go faster. If RPMs drop when going faster, then you should put lighter rollers in the bike, if you want max acceleration, and max top speed.
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or are they
