Top Speed

[Anime2019Master]

could be jetted too lean or have an air leak that will rob a lot of power

I check my plug after every change of parts, after 30 miles or so with new parts, its a nice tan color, according to a plug chart i found its the right heat range, though that i expect to change when i modify the engine. Im also very careful about air leaks, though i could miss one, i just fixed a leak not too long ago, head had vibrated loose and was leakin there.

The cdi if it has a lower base timing and less advance as rpm climb also helps to keep it smoother plus helps to get a better burn of more fuel with a stronger spark which will then make a bit more power.

I was planning on replacing the cdi with one of those keyed ones, here the one i have ordered, is this a good one?

Thunder CDI for 48cc 66cc 80cc - High Performance | Gasbike.net

Thunder CDI for 48cc 66cc 80cc - High Performance Upgrade your CDI to this high powered Lock secured unit. Keys used to disable the CDI from firing to add some security to your bike. What you need is more spark. This easy installation will give your motor the power it craves. - High-Performance...

www.gasbike.net

This is the ported piston and jug i have been eyeing, waiting on them to be in stock

https://bicyclemotorworks.com/product/professionally-ported-cylinder-piston/

If not do you have a suggestion? I dont trust myself to do it, im afraid id leave an edge that cause issues, id rather buy one pre-ported. Not to mention im not 100 % sure this will fit my engine, hough it looks like it will, i dont have the zeda80, i have a bbr tuning. Also is there any other parts you would recommend i get? I use my bike as my main transportation, i do like speed, but not at the expence of all my torque, or if its a great risk of detonating the engine. I want it to last. I ride it daily on the road, so not being constantly in the way of traffic is nice. I prefer to be going fast enoigh that they dont get too irritated at being stuck behind me unil its safe to pass. Otherwise they have a habit of passing when its not safe if im way too slow, putting both then and myself at risk.

 

[Chainlube]

Here you go, https://heliobikes.com/collections/...ts/motorized-bicycle-super-pk80-cylinder-only
Get a high speed rotary tool with the flex shaft extension and have some fun. If it turns out perfect, then use it. If something else happens, chuck it away and try again, you can't buy any kind of lessons these days for 30 bucks/

 

[Anime2019Master]

Here you go, https://heliobikes.com/collections/...ts/motorized-bicycle-super-pk80-cylinder-only
Get a high speed rotary tool with the flex shaft extension and have some fun. If it turns out perfect, then use it. If something else happens, chuck it away and try again, you can't buy any kind of lessons these days for 30 bucks/

Okay thats not too bad a price, theres vids on youtube for how to cut it, and i already have a dremal, so ill give it a shot. Its alot easier to find ported pistons than jugs ive noticed, but i know a ported piston w/o the jug being ported is losing potential.

 

[Street Ryderz]

I check my plug after every change of parts, after 30 miles or so with new parts, its a nice tan color, according to a plug chart i found its the right heat range, though that i expect to change when i modify the engine. Im also very careful about air leaks, though i could miss one, i just fixed a leak not too long ago, head had vibrated loose and was leakin there.
View attachment 101318

I was planning on replacing the cdi with one of those keyed ones, here the one i have ordered, is this a good one?

Thunder CDI for 48cc 66cc 80cc - High Performance | Gasbike.net

Thunder CDI for 48cc 66cc 80cc - High Performance Upgrade your CDI to this high powered Lock secured unit. Keys used to disable the CDI from firing to add some security to your bike. What you need is more spark. This easy installation will give your motor the power it craves. - High-Performance...

www.gasbike.net

This is the ported piston and jug i have been eyeing, waiting on them to be in stock

https://bicyclemotorworks.com/product/professionally-ported-cylinder-piston/

If not do you have a suggestion? I dont trust myself to do it, im afraid id leave an edge that cause issues, id rather buy one pre-ported. Not to mention im not 100 % sure this will fit my engine, hough it looks like it will, i dont have the zeda80, i have a bbr tuning. Also is there any other parts you would recommend i get? I use my bike as my main transportation, i do like speed, but not at the expence of all my torque, or if its a great risk of detonating the engine. I want it to last. I ride it daily on the road, so not being constantly in the way of traffic is nice. I prefer to be going fast enoigh that they dont get too irritated at being stuck behind me unil its safe to pass. Otherwise they have a habit of passing when its not safe if im way too slow, putting both then and myself at risk.

The ported cylinder you've shown in the link is a Zeda jug and they say it will suit a gt5 which is what you have but that makes no sense to me as there is a 2mm difference in stroke between the two which means for the gt5 type the piston will sit low in the tdc position and reduce compression requiring the jug to be decked to correct it, so yes it will work but still needs work to be ideal and I've not seen their port work yet so I can't really say if it's good or not but I'm sure it will be somewhat of an improvement. The cdi is good but the cheaper supper charged cdi they sell is actually better suited to our needs tbh.

 

[Street Ryderz]

Here you go, https://heliobikes.com/collections/...ts/motorized-bicycle-super-pk80-cylinder-only
Get a high speed rotary tool with the flex shaft extension and have some fun. If it turns out perfect, then use it. If something else happens, chuck it away and try again, you can't buy any kind of lessons these days for 30 bucks/

This cylinder is not really suited to his gt5 as this one is meant for 40mm stroke short rod and he has 38mm long rod the cylinder will then also need to be decked and port timing corrected.

 

[Street Ryderz]

Okay thats not too bad a price, theres vids on youtube for how to cut it, and i already have a dremal, so ill give it a shot. Its alot easier to find ported pistons than jugs ive noticed, but i know a ported piston w/o the jug being ported is losing potential.

There is no such thing as a ported piston, they are windowed for the use of a reed valve on a piston port engine type that uses the cylinder intake port to fit the reed block rather than case induction which doesn't require the windowed piston, this window now control's the intake timing along with the port location.

 

[CrazyDan]

There is no such thing as a ported piston, they are windowed for the use of a reed valve on a piston port engine type that uses the cylinder intake port to fit the reed block rather than case induction which doesn't require the windowed piston, this window now control's the intake timing along with the port location.

I think he meant a ramped piston.

 

[Anime2019Master]

This cylinder is not really suited to his gt5 as this one is meant for 40mm stroke short rod and he has 38mm long rod the cylinder will then also need to be decked and port timing corrected.

This is the engine kit i bought if it helps, (yes i know bikeberry sucks, but at the time i bought it, couldnt find a reasonable priced kit that wasnt junk). I had to replace some of the crappy bits, like the muffler, and paper thin gaskets. Does this one have the 38mm? Ive heard the 40mm was better. If so, is it possible to change it? Or would i need a new engine altogether to do this, assuming its worth it. Id much rather be able to change it since thia engine is nicely broken in already.

BBR Tuning Racing Series Stage 4 66/80cc 2-Stroke Engine Kit

BBR Tuning and its Racing Series 2-stroke engine kits can turn any motorized bike into a race-day monster. Comes with install guide. Shop now!

www.bikeberry.com

Edit: its not the flying horse, i dont know why the link says that, but it goes to the right place.

There is no such thing as a ported piston, they are windowed for the use of a reed valve.

I was thinking of the windowed one, i assumed that meant ported, (never researched much into portig since if i do it wrong ive ruined my part) but i have seen people in porting videos cutting a bit off the bottom of the piston, but its been awhile, i forget what the reasoning behind it was. But on the subject of reed valve, would that be a worthwhile purchase? Or would it not work with my engine.

I think he meant a ramped piston.

Probably, assuming thats what i mentioned above

 

[Chainlube]

This cylinder is not really suited to his gt5 as this one is meant for 40mm stroke short rod and he has 38mm long rod the cylinder will then also need to be decked and port timing corrected.

Neither of those state whether they are for 38 or 40 mm stroke. How do you tell?

 

[gary55]

Neither of those state whether they are for 38 or 40 mm stroke. How do you tell?

That is a good question because it is hard to know for sure without having seen the rod. If it has a type A piston you know it's a short rod long stroke engine, but type B's come in both long rod long stroke and long rod short stroke. Then we have the G4 cylinders which are in now coming in the differing deck heights. A engine being 2.779" to 2.782". B engines at 2.739" to 2.744". I'm almost sure the Bikeberry engine here is the A type with a 40mm stroke. This should be the jug for it.
2-Stroke Motorized Bicycle Engine Cylinder Body | BikeBerry