maximum RPM/speed

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5500 RPM, huh? I'm using the stock CDI, but 5500 RPM means 53km/h for me, which is a cruising speed for me. My max. was 70km/h at 7500 RPM still with the stock CDI. So what are we talking about? Without any load it can rev up to 10 000 RPM.
We're talking about how to begin the process of tuning the engine not by leaping straight to the exhaust port and raising it. :)

There's good reason to begin with getting the most out of every stroke. Making good torque is essential for the bike to get the speed so you might actually get 1.5 times the RPM or whatever you dream of. There's enough torque to gain by tuning (such as retarding ignition at high RPM) that you could run a smaller rear sprocket and raise the top speed RPM too. :)

If you can do 43mph at only 7500 then you likely already don't have a stock 2014 engine. It clearly makes more torque than the stock 2014 engines that are commonly available in South America and the rest of the world, so tell us how your engine makes its torque! Is it a newer version? Grubee? Zeda? Did you tune it to make the best torque? What did you do? :)
 
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7.5mm carbide drill bit View attachment 80825
Very nice but you also have the drill press to put it in!

Is no one selling drilled out wrist pins? Would be a bit cheaper than a drill press lol.

Not to worry though, if anyone doesn't have the machine shop in their garage; It is possible, IME, to get the vibration so low it isn't a concern at all at any speed, and is totally comfortable at cruising speeds.

I retarded the timing (AT ALL RPM) by making an offset magnet key, and I drilled balance holes in the crank without removing it (and with a common cordless drill!), and I lightened the piston and upper part of the connecting rod, but I didn't have to drill out the wrist pin or split the case. So if you have limited space or resources you can still do enough to make a big difference, even without any seriously large, heavy or expensive tools.
Hopefully I can also have total comfort and better torque at high RPM with a better CDI. ;););)
 
Would a lathe work? I have one of those kicking around.
I should think a lathe is preferable but there's only so many members have either so I'm just pointing out that the less well equipped members and lurkers can still get good results by doing all the other stuff I mentioned which doesn't require any larger tools. Although it would be better and easier to lighten the wrist pin, if you can. :)
 
I should think a lathe is preferable but there's only so many members have either so I'm just pointing out that the less well equipped members and lurkers can still get good results by doing all the other stuff I mentioned which doesn't require any larger tools. Although it would be better and easier to lighten the wrist pin, if you can. :)

Yes defiantly, I agree
They can be pricey so if you buy hoping just to use a hand drill I wouldn’t attempt it and may be an expensive lesson
Even a bench drill will be tricky without a good vise.
As Jag mentioned it’s probaly easier to go to a machine shop

I had the idea of drilling them out and selling them, see how it goes

I’ve been very lazy in doing it all though haha
 
Yes defiantly, I agree
They can be pricey so if you buy hoping just to use a hand drill I wouldn’t attempt it and may be an expensive lesson
Even a bench drill will be tricky without a good vise.
As Jag mentioned it’s probaly easier to go to a machine shop

I had the idea of drilling them out and selling them, see how it goes

I’ve been very lazy in doing it all though haha
I wouldn't attempt it with a hand drill either! There's absolutely no chance of getting the hole centred all the way through the pin, and it is a very hard steel which will need to be cooled and lubed with cutting fluid.

{{ Mainly aimed at future lurkers:
It's okay to use a hand drill and silicone lube aerosol spray to drill balance holes in the crank because they don't require such precision and I think it's just a mild steel.
Still, use a 3/16" carbide bit for the pilot holes before using the 3/8" carbide bit to finish the radially drilled balance holes (about 15mm deep seems to do it). }}

If you find it's economical to drill out individual pins to sell that would save a lot of work lightening the piston and rod so they should be popular (if people have sense). I just expect it to take too much time and carbide bits to be viable. If the pins were manufactured with thinner wall in the first place it might be a better way.
 
5500 RPM, huh? I'm using the stock CDI, but 5500 RPM means 53km/h for me, which is a cruising speed for me. My max. was 70km/h at 7500 RPM still with the stock CDI. So what are we talking about? Without any load it can rev up to 10 000 RPM.
How please teach me I'm very very dumb to this because I'm new but I will remember if you make it easy for me tnks
 
5500 RPM, huh? I'm using the stock CDI, but 5500 RPM means 53km/h for me, which is a cruising speed for me. My max. was 70km/h at 7500 RPM still with the stock CDI. So what are we talking about? Without any load it can rev up to 10 000 RPM.
It also depends on the brand of engine you have some Brands don't have high RPM tuned cdi's but yours may have came stock with something a little bit better.

I've even bought a couple of really cheap Amazon engines that do come with better CD eyes and I've also bought a $600 80cc two stroke engine that came with the crappy one, it all depends on the brand and where you buy it, but for the most part everything they're talking about is 100% true because even with the Amazon engines I have bought three of the same engines one of them topped out at about 80 km an hour and the other topped out at around 60 km an hour and the last one topped out at around 40 km an hour max all of the engines have the same Hardware and parts, they were all put on the same type and size of bike but yet they all run at different speeds because it all depends on balancing the parts, the tuning, the compression, and so much more.

A lot of these engines are not made very well and they are not very well balanced when it comes to other engines of the same type, hence why I also recommend just getting a 80 to 100 cc four stroke engine they are much more reliable, they last a lot longer, they're much quieter, and it has centrifical clutch instead of manual clutch which can be very easy for some of the beginner Riders that Buy My Bikes.
 
This thread is now locked out from further replies because of repeated attempts to revive an ancient thread, especially when they are replying to a an account that was not only deleted, it was one of the old guest accounts at that from 2014...lol...lol.

Deleted member 12676

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Also two of the other members in this discussion are now deceased as noted on their avatars.

Reading is fundamental people, please look at the date codes to what your replying to as well as if they are even alive anymore, we DO mark that when we are made aware of someones death.
 
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