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Post by abokayed on Mar 31, 2019 12:46:15 GMT -5
Hello There! i would really appreciate some help or advice from any experienced members , as it would really help me make a choice and enhance my ability to mod my scooter in a better aspect! i have a Chinese Maxi-Scooter , a exact copy of Yamaha Xmax 250 CC but with a 150cc GY6 Engine , in couple days i will be changing my whole engine to a 250 cc Water cooled engine , since i decided ti make some trips using this scooter , and will make it my daily use , it is proven reliable with a tons of fuel economy , i will leave some pictures for it at the end of this thread! , now my questions as follows: - after upgrading to my 250 cc Engine , i want the best advice on torque spring and clutch springs and sliders option to get the best performance on highway speeds - please let me know what is the best combination of Clutch Springs , Torque Spring and sliders or rollers for highway speeds to make my engine give me the best highway speed without having the Rev's to be high so the engine can work efficiently and wouldn't cause and unnecessary stress on it on high speeds , i do use my scooter for city , but having it setup for high way cruising wouldn't have much difference for city riding (i do know they are totally opposite in terms of modifications) any help or advice would be highly appreciated Here is some photos for my Scooter    with my best regards  |
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Post by 90GTVert on Apr 1, 2019 14:16:06 GMT -5
 Nice looking scoot. I didn't realize they were copying the XMAX already, but I guess Chinese manufacturers don't waste time ripping the big brands off. lol Most likely you will be able to get the new engine tuned up pretty well with a set of sliders. I use sliders instead of rollers because they sometimes give a small performance benefit, but have been longer lasting for me. Unfortunately I can't tell you which sliders will work best for you. There are different 250s out there, so I would suggest figuring out what engine you have and then searching more specifically for it. You probably won't need to mess with the torque spring. Some people don't even like stiff clutch springs on smaller scooters because it takes more throttle/RPM to get moving. With the 250, you may be happy with it in stock form so I would advise seeing how you like it once you tune with rollers/sliders and swap clutch springs only after that if you still think it's necessary.
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Post by abokayed on Apr 1, 2019 17:00:22 GMT -5
Thanks for your valuable reply Sir! haha about the Chinese manufacturers , its crazy how exact details they made it look like the yamaha xmax! , i was really amazed its an exact copy!, except for the most important parts which is quality and engine  anyhow thank you for the nice information you gave me , yes i will be willing to see the stock version first before i do any kind of modification , i do have a question for you since i noticed you have many scooters owned and one of them was Tmax 500 , will i see that significant difference between my 150 cc and 250 cc , i am also thinking of a big bore kit on the 250 cc to make it 300 cc what is your thoughts about that?! Regards |
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Post by 90GTVert on Apr 1, 2019 23:27:30 GMT -5
I don't really have personal experience with the 250s, but it should be good for 70MPH or more where the GY6 150 would be more like 50-60MPH in most cases. It should accelerate more quickly and be able to maintain higher cruise speeds.
Regarding the BBK, I hate to be broken record but I would suggest seeing how you like the 250 first. The BBK should give you more power but may do better with a larger carb. Some even say a larger carb is a good mod on a stock 250, but I don't have experience with the 250s to tell you if that's true. A lot of times leaving the engine alone for the most part (I mean mods not maintenance) leaves you with the most reliable setup.
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Post by abokayed on Apr 2, 2019 8:13:47 GMT -5
I don't really have personal experience with the 250s, but it should be good for 70MPH or more where the GY6 150 would be more like 50-60MPH in most cases. It should accelerate more quickly and be able to maintain higher cruise speeds. Regarding the BBK, I hate to be broken record but I would suggest seeing how you like the 250 first. The BBK should give you more power but may do better with a larger carb. Some even say a larger carb is a good mod on a stock 250, but I don't have experience with the 250s to tell you if that's true. A lot of times leaving the engine alone for the most part (I mean mods not maintenance) leaves you with the most reliable setup. thanks alot for your reply again! i can totally agree with your mentioned point , on trying the 250 CC First before doing any modification, this is what i was thinking , i will try it out and see the power its making as long as it is enough for my needs , and short - long trips , i will be good without any modification , but you know this worm inside me playing telling me "Hey you! , lets go stronger lets go faster " , i hope this 250CC stock can shut her up a little bit , lets see! , i will write my numbers and full review here after testing it out! about your second point for having the best reliability on stock , i do agree also on that one , since the stock parts are made for their performance limits , adding more power may really hurt it in the long run , since its not a branded product after all , so the reliability is always questionable , but lets see how everything goes - i do have a question in regards of the carb upgrade , since i really have few to no experience in them , i do understand how they work , and the carb parts and main jet , pilot jet ... etc , i read somewhere for 250CC recommended carbs are the 30mm , and the best carbs are 32mm , but i still have my questions about the jets , do they need to be modified and for what number to get the best out of it?! thanks again and sorry for my too many questions Regards |
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Post by 90GTVert on Apr 2, 2019 8:35:36 GMT -5
I'm looking forward to seeing how the 250 does for you. I have always had that voice telling me I need to go faster or make more power, as prob most of us do. I have tried to avoid it on the big scoot because my number one priority is reliability. Plus, IMO if you have a strong urge to mod and feel improvements, then smaller scoots are actually more fun and generally more economical (although mods rarely make good financial sense). I use my 49cc based stuff for projects and the TMAX is what I hope to just hop on and ride. That way I can mod till my heart is content (or more likely my wallet is empty) and know I've got a reliable scoot waiting in the garage for when parts inevitably fail on the projects. A 300cc version of your 250 may be very reliable, I don't really know, but more power creates more stress and that will find any weakness in the system.
If you install a larger carburetor, you will still need to tune it for the best results. I have seen plenty of people bolt a carb on and never think twice about it and live happily ever after. I have also seen people install a carb and their scoot barely goes. I have seen people swap stock replacement carbs on and they won't run right. If you want the most out of a setup, it must be tuned unless you just happen to get lucky and the carb is perfect for your scoot and conditions.
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Post by abokayed on Apr 2, 2019 9:47:41 GMT -5
I'm looking forward to seeing how the 250 does for you. I have always had that voice telling me I need to go faster or make more power, as prob most of us do. I have tried to avoid it on the big scoot because my number one priority is reliability. Plus, IMO if you have a strong urge to mod and feel improvements, then smaller scoots are actually more fun and generally more economical (although mods rarely make good financial sense). I use my 49cc based stuff for projects and the TMAX is what I hope to just hop on and ride. That way I can mod till my heart is content (or more likely my wallet is empty) and know I've got a reliable scoot waiting in the garage for when parts inevitably fail on the projects. A 300cc version of your 250 may be very reliable, I don't really know, but more power creates more stress and that will find any weakness in the system. If you install a larger carburetor, you will still need to tune it for the best results. I have seen plenty of people bolt a carb on and never think twice about it and live happily ever after. I have also seen people install a carb and their scoot barely goes. I have seen people swap stock replacement carbs on and they won't run right. If you want the most out of a setup, it must be tuned unless you just happen to get lucky and the carb is perfect for your scoot and conditions. I am so excited for the 250 cc , my stock engine now the 150 cc , is doing well and to be honest its more than enough power for city driving and little cruising here and there , but the Terrain in my country Jordan , especially the city im living in , is mostly mountains and uphills - downhills , so to reach good enough speeds on the roads especially when its uphill , i do need for sure more power to maintain speeds for uphills , considering what you said about having a cheaper scoot for modding , and a large scoot for daily usage i totally agree , but sadly enough in my country it is really expensive to do so , you cant imagine the Customs and taxes we pay here , an average chinese scooter price here is around 1800+ USD , while i saw it online in USA and other countries for around 700-1200 USD , which makes it really expensive to own more than one scoot and mod it , thats why im willing to spend such money on my existing scooter to make it better in terms of power, my local mechanic made a deal for me for the 250 cc engine with a total kit of radiator , carb, CDI , and tire replacement for around 1000 USD , which is a bargain! , espically considering the taxes and shipping and customs and all related prices to get it here from overseas, thats what made me excited to do the upgrade for it , hoping it works well for me. as for now i will leave everything in stock , and test it out and see how it performs , ill keep you updated Thank you! |
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Post by 2stroked on Apr 2, 2019 16:09:55 GMT -5
The CN-250 Honda clone engines (vertical cylinder no more than 12 inch rear wheel) will give you 75-80MPH stock, in a bigger heavier bike, with a 200 pound rider.
The Linhai/Yamaha 260 (horizontal cylinder 13&14 inch rear wheel) can give you the same 75-80MPH Stock with a 200 pound rider.
Playing around with the Hondamatic clone CVT which both engine variants use, is a craps shoot. The best mod to those CVTs is to remove the rollers, clean and remove all the grease, and lube the rollers/ ramps with graphite powder. It yields a bump in acceleration a few mph top end and kills the sluggish shifting that comes with old dirty grease.
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