Joined: Wed Nov 28, 2007 1:21 am Posts: 4044 Location: Seattle, WA
It looks like your Yamaha-based engine has a CVT so there should be some sliders and torque springs that will tune the engine more for your riding. Are you trying to get faster speeds or better torque for climbing?
Do you have a chain that drives the rear wheels or is driven by gears and shaft? Chain driven rear ends can be geared using different size sprockets.
Overall performance will increase if you replace the air intake box with a low restriction 5cm (2 inch) filter. It will breathe air so much better that you will have to increase the main jet to compensate for this additional air.
I am not sure if there is a CDI that will work with your engine, but you can get a performance coil and spark plug to give you a better spark at higher RPMs.
The people running Yamaha-type engines will be able to give you specific part numbers and sizes to help more.
It looks like your Yamaha-based engine has a CVT so there should be some sliders and torque springs that will tune the engine more for your riding. Are you trying to get faster speeds or better torque for climbing?
I want better torque
Do you have a chain that drives the rear wheels or is driven by gears and shaft? Chain driven rear ends can be geared using different size sprockets.
I haven't a chain on my buggy
Overall performance will increase if you replace the air intake box with a low restriction 5cm (2 inch) filter. It will breathe air so much better that you will have to increase the main jet to compensate for this additional air.
And i must change the main jet to what ?
I am not sure if there is a CDI that will work with your engine, but you can get a performance coil and spark plug to give you a better spark at higher RPMs.
Yes i think it works with a CDI but i don´t know what it is. I will change the spark plug, and i will put an Iridiun one. What d you think of it? Must i change the CDI unit? What should i choose?
The people running Yamaha-type engines will be able to give you specific part numbers and sizes to help more.
Thank you very much for your help and i will wait for more helps. Regards....
Joined: Wed Nov 28, 2007 1:21 am Posts: 4044 Location: Seattle, WA
For better torque, you will reduce the weight of your current sliders (17g) and increase the spring rate (stronger 2500 RPM spring) of the torque spring behind the clutch. Someone with a similar engine will have to help you with size suggestions, but my advice works with any CVT.
Since there is no chain and sprocket, the CVT modifications will be your biggest improvement in gearing. If you need a lower gear, you may have to use smaller diameter rear tires to get the desired ratios.
I do not know what size jet you currently are using in your carburetor. Typically when people add the low restriction air filter, they increase the jet size by 20-30%. Much of this sizing must be done by testing and examining the spark plug: White contacts means the jet is too small, black contacts means the jet is big, and brown contacts means it is the correct size.
Yes, you have a CDI for your ignition. For some engines there are performance CDIs that will advance the spark timing more at lower RPMs to give additional torque. I do not know if there is a performance CDI for your Yamaha engine. The NGK Iridium spark plug has been rated well by many people. If you upgrade the plug or coil, you do not have to upgrade the CDI to make them work correctly.
Use the search function in the forum to find more information about your engine and what others have done to improve performance.
For better torque, you will reduce the weight of your current sliders (17g) and increase the spring rate (stronger 2500 RPM spring) of the torque spring behind the clutch. Someone with a similar engine will have to help you with size suggestions, but my advice works with any CVT.
I must reduce the sliders to 17g or my sliders now are 17g?
Since there is no chain and sprocket, the CVT modifications will be your biggest improvement in gearing. If you need a lower gear, you may have to use smaller diameter rear tires to get the desired ratios.
I do not know what size jet you currently are using in your carburetor. Typically when people add the low restriction air filter, they increase the jet size by 20-30%. Much of this sizing must be done by testing and examining the spark plug: White contacts means the jet is too small, black contacts means the jet is big, and brown contacts means it is the correct size.
Yes, you have a CDI for your ignition. For some engines there are performance CDIs that will advance the spark timing more at lower RPMs to give additional torque. I do not know if there is a performance CDI for your Yamaha engine. The NGK Iridium spark plug has been rated well by many people. If you upgrade the plug or coil, you do not have to upgrade the CDI to make them work correctly.
Use the search function in the forum to find more information about your engine and what others have done to improve performance.
Joined: Wed Nov 28, 2007 1:21 am Posts: 4044 Location: Seattle, WA
Sansoni7 wrote:
pghruby wrote:
For better torque, you will reduce the weight of your current sliders (17g) and increase the spring rate (stronger 2500 RPM spring) of the torque spring behind the clutch. Someone with a similar engine will have to help you with size suggestions, but my advice works with any CVT.
I must reduce the sliders to 17g or my sliders now are 17g?
You must purchase sliders that are 17g. The current ones are heavier and cause the CVT to shift to a higher gear too quickly. The sliders are measured by height and width in millimeters. To get the correct size, you will need to measure your current sliders or search this forum for someone who has already done the measurement in your model of engine.
The 2500 RPM torque spring also has to be the correct diameter for your clutch assembly and you will need to get measurements.
Hidie Ho! Welcome to the forum. I have some knowledge of your engine, firstcan you get a picture of the rearend of your buggy? Will you be doing the work yourself? I have lots of pics that can help if your buggy is what I think it is, It is time for me to be off to work, I will post again when I return. How is your french? I know of some forums and websites you could get things from. for now check this link. http://krusekontrol.net/phpbb2/viewtopic.php?p=102#102
_________________ Turbo Turtle, Viper Jr. (for the little man)
Hidie Ho! Welcome to the forum. I have some knowledge of your engine, firstcan you get a picture of the rearend of your buggy? Will you be doing the work yourself? I have lots of pics that can help if your buggy is what I think it is, It is time for me to be off to work, I will post again when I return. How is your french? I know of some forums and websites you could get things from. for now check this link. http://krusekontrol.net/phpbb2/viewtopic.php?p=102#102
Thanks and i wil wait all the news. I think i understand french. I will send you a PM with my mail to have your pics. And here it is a rear pic from my buggy:
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