Engine differences and upgrade question...

[mhardgrove]

Question. I am finding a lot of info on gy6 engines, and would eventually like to up the displacement from 125cc. I am a little confused about parts because I hear that the gy6 was an old honda engine that is now used by many different scooter makers, and apparently each maker has differences between them. I could be wrong, and if so please correct me. I don't want to buy something that I cannot use due to minute differences in design.

Does PGO make it's own version of the gy6 or does it buy it from another maker? Also, what are the main differences between the 125cc and 150cc, and is it possible to make my 125 into a 150 by just replacing the cylinder and piston, or would I have to replace the crank, head, and computer controls? Thanks!

[illnoise]

Question. I am finding a lot of info on gy6 engines, and would eventually like to up the displacement from 125cc. I am a little confused about parts because I hear that the gy6 was an old honda engine that is now used by many different scooter makers, and apparently each maker has differences between them. I could be wrong, and if so please correct me. I don't want to buy something that I cannot use due to minute differences in design.

That's an accurate description. The GY6 was a honda engine that's been copied by countless other manufacturers. PGO's engine is loosely based on the GY6 format, less so than most mainland Chinese bikes'.

Certain GY6 parts fit (or can be modified to fit) on a PGO engine, but even in the more similar knockoffs, a perfect fit should never be taken for granted, and that goes double for PGO, it's more the exception than the rule.

Does PGO make it's own version of the gy6 or does it buy it from another maker? Also, what are the main differences between the 125cc and 150cc, and is it possible to make my 125 into a 150 by just replacing the cylinder and piston, or would I have to replace the crank, head, and computer controls? Thanks!

PGO does make their own engines. I'm not too great with 4-strokeness, but as I understand it, the 150s have an oil cooler and some added features that the 125s don't, though the general design is pretty similar.

With a 2-stroke, it's often easy to slam a bigger cylinder/piston on any bike, but I'd imagine with the valves/head design and such, it's not so easy with a 4-stroke. There are kits made specifically for the Bubu, at least one is available through dealers, but there are allegedly others available in taiwan.

Bb.

[jfrost2]

In simple terms, every company makes their own engines, though many are based off gy6 technology, different parts of the engine are different sized. It's hard to find a bigger displacement that will fit and work perfect on the buddy 125. And if you can find one, it probably is chinese. Seeing how they manufacture 250cc bikes that can do a top speed of 60mph, and the Taiwanese can manufacture a 125cc bike that can do 60mph too, chinese quality isnt the best.

The only true way to upgrade would be to use a totally different engine and mount that into the frame, but different engines made for different frames, wont fit, you'd need to rebuild the frame from scratch.

[Kaos]

Question. I am finding a lot of info on gy6 engines, and would eventually like to up the displacement from 125cc. I am a little confused about parts because I hear that the gy6 was an old honda engine that is now used by many different scooter makers, and apparently each maker has differences between them. I could be wrong, and if so please correct me. I don't want to buy something that I cannot use due to minute differences in design.

Does PGO make it's own version of the gy6 or does it buy it from another maker? Also, what are the main differences between the 125cc and 150cc, and is it possible to make my 125 into a 150 by just replacing the cylinder and piston, or would I have to replace the crank, head, and computer controls? Thanks!

I've been working on this problem for quite a while. Yes the PGO engine is loosely based on the Honda GY6, and many GY6 parts will fit. Unfortunately there's not (yet) a cylinder kit that will fit the 125. The 125 engine has an extended rod length thats fixed some of the GY6's sideloading problems. Unfortunately that means that the stock GY6 cylinder kits are too short for the 125. I'm actually working on fabricating an adapter set that will allow this, but its not quite ready for primetime. Until then, there are many other parts that WILL fit and can add quite a bit of performance to the 125(PM Me if you need specific parts).

[jfrost2]

It would be safer to just add a dr pulley variator, sliders, and prima pipe to add performance than to upgrade the displacement.

[Kaos]

It would be safer to just add a dr pulley variator, sliders, and prima pipe to add performance than to upgrade the displacement.

Depends on your definition of "Safer" I guess. Safer as in safety of the rider? I don't think there's any difference as long as the rider is still riding reasonably. If you're talking safety as in well tested known parts? Absolutely.

I just enjoy pushing the envelope a bit, so I'm more than willing to experiment with parts that are largely untested on our engines. I'm also fully aware that I could very easily do some major damage to my engine in doing so I feel that I'm skilled enough of a mechanic to take that risk, its up to you to determine if you feel the same.

[jfrost2]

By safer I just meant for the engine over all. We know those parts work well and last with the buddy. So it's a bit easier to install these and be worry free.

[olhogrider]

The PGO piston, wrist pin and rod are also not compatible with Chinese GY6 engines.

[Kaos]

The PGO piston, wrist pin and rod are also not compatible with Chinese GY6 engines.

Really? I understood the rod wasn't (its longer than the usual GY6 one)
But I have been told by several people the wrist pin and piston were the same.

[olhogrider]

Nope. The wrist pin on the GY6 is way bigger. That means the rod and piston won't work either. Thanks to a liberal return policy or I would have a set of useless parts in my garage.

[Kaos]

Nope. The wrist pin on the GY6 is way bigger. That means the rod and piston won't work either. Thanks to a liberal return policy or I would have a set of useless parts in my garage.

Well, crap muffins. I've been working on fabbing up a 2MM spacer plate to kit my 125, guess I'm back to the drawing board unless I can get a custom piston made up. I don't know if it'd be worth the costs though from what they usually cost when I have had them made for my hotrods.