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[gary55]

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.

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.

Probably, assuming thats what i mentioned above

these are examples of a windowed piston that is required for a reed timed engine unless you use a 3 transfer jug.

Reed Valve Windowed Lower hole piston 15/16" 25m 80cc gas Motor ENGINE bicycle | eBay
Reed Valve Windowed Lower hole piston 15/16" 25m 80cc gas Motor ENGINE bicycle | eBay
this is a 3 port cyl.
View media item 60553This is a ramped piston
View media item 62022
View media item 62021
View media item 60110
View media item 61990

The notch at the bottom intake side of the piston is for a longer intake duration and clearer path of flow. That is a skirted piston.

 

[gary55]

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.

I'm not 100% sure on this as they have changed so much stuff and the labeling of it around lately that I just don't have the hands on with all the new configurations. I thing though that the jug helio is showing called out for a super PK80 and that is what CDH was calling PK80 using the same rod and piston as the Zeda engines, long rod long stroke B type with the 2.740" jug.
Amazon.com : Super PK80/Silver 2 Stroke Bicycle 80cc Engine kit with CDH66 Muffler - Gas Motorized Bicycle : Sports & Outdoors

Then there is this one having the same casting as the helio jug calling out the long stroke, but nothing on the rod/piston setup so we are in the dark about the cylinder height. I'm so confused.

https://www.amazon.com/Anbull-Bicycle-Engine-Motorized-Stroke/dp/B087LS33B2/ref=pd_day0_468_3/134-4076540-4142123?_encoding=UTF8&pd_rd_i=B0829XT4W9&pd_rd_r=af50cf53-18c3-4cba-b927-2e8d2ae47731&pd_rd_w=LcU8o&pd_rd_wg=bEro3&pf_rd_p=ecf748b5-e796-4a0d-9a46-406a973ba8da&pf_rd_r=778BSSNR7WYWB90SEP8N&psc=1&refRID=778BSSNR7WYWB90SEP8N

 

[Chainlube]

Ha ha, YOU'RE confused! I'm off the deep end! I guess the other option is getting a rod and piston to match the jug.

Those two motors you posted were the first I've seen with and B & S stated. Try to find a bore measurement on any single jug for sale?!

 

[Anime2019Master]

Ported G4 80cc/66cc Cylinder (Fits Wildcat) | website

This cylinder is a cheap and easy upgrade! Has OPTIONAL transfer port so it can be used with reed valve or without. Swap out your stock cylinder for this fully ported cylinder today to maximize your engine performance with minimal investment. WIDER...

www.californiamotorbikes.com

I found this, this one is cheap and pre ported.

Wildcat 80cc (Engine Only) | website

Engine only, NO KIT INCLUDED. 80cc Wildcat replacment ready to bolt on!Trued crank with 38mm rod. Gasoline operated products are NOT compliant with Environmental Protection Agency ( E.P.A. ) or California Air Resources Board (C.A.R.B) for the use on/off Public roads. Upon purchase, the buyer...

www.californiamotorbikes.com

Ive been debating buying this engine anyway, my first build was a pk80, (stolen sadly) and it was a very good motor. If i bought this one id be pretty well set for replacement parts if something goes wrong, since id have 2 complete engines. I can start buy just buying the jug and see if it fits on my current engine, if not, i can always buy the wildcat. I travel alot, so having a backup engine would be a good investment. I already carry a full assortment of bolts, masterlinks, gaskets, and woodruff keys. Dont really have any spart motor parts. Having the extra weight would be a shame, but since im planning an upcoming cross crountry trip next spring, itd be worth the weight. Im a light rider anyway, so it wony matter much i think. Already carry like 20lbs in parts anyhow.

 

[Chainlube]

Ported G4 80cc/66cc Cylinder (Fits Wildcat) | website

This cylinder is a cheap and easy upgrade! Has OPTIONAL transfer port so it can be used with reed valve or without. Swap out your stock cylinder for this fully ported cylinder today to maximize your engine performance with minimal investment. WIDER...

www.californiamotorbikes.com

I found this, this one is cheap and pre ported.

Wildcat 80cc (Engine Only) | website

Engine only, NO KIT INCLUDED. 80cc Wildcat replacment ready to bolt on!Trued crank with 38mm rod. Gasoline operated products are NOT compliant with Environmental Protection Agency ( E.P.A. ) or California Air Resources Board (C.A.R.B) for the use on/off Public roads. Upon purchase, the buyer...

www.californiamotorbikes.com

Ive been debating buying this engine anyway, my first build was a pk80, (stolen sadly) and it was a very good motor. If i bought this one id be pretty well set for replacement parts if something goes wrong, since id have 2 complete engines. I can start buy just buying the jug and see if it fits on my current engine, if not, i can always buy the wildcat. I travel alot, so having a backup engine would be a good investment. I already carry a full assortment of bolts, masterlinks, gaskets, and woodruff keys. Dont really have any spart motor parts. Having the extra weight would be a shame, but since im planning an upcoming cross crountry trip next spring, itd be worth the weight. Im a light rider anyway, so it wony matter much i think. Already carry like 20lbs in parts anyhow.

I'm really having a hard time believing either of those, that jug just looks like it's ported on exhaust side. If they did the intake and transfers, why not show a picture?

 

[Anime2019Master]

I'm really having a hard time believing either of those, that jug just looks like it's ported on exhaust side. If they did the intake and transfers, why not show a picture?

Eve if they didnt do a complete port its still about the same price as the jug posted earlier, so i could try to port the rest(if needed) myself, at the same approx cost if fail

 

[Chainlube]

Eve if they didnt do a complete port its still about the same price as the jug posted earlier, so i could try to port the rest(if needed) myself, at the same approx cost if fail

I'm not saying they didn't do the intake side, but were lazy in taking the picture. If you have the funds, just get the complete, but go through it before you install. It's not hard to pop off the head and jug to chamfer the inside of the ports, It gives you a chance to swap out those acorn nuts for some real nuts.

 

[Anime2019Master]

Okay ill buy this one when i get a chance, it cant hurt to check i out.

 

[gary55]

I have no experience with the vendor you are showing, but I know bulls**t when I see it, and that is what I am seeing in their ad where it says "why our engines".
First they say there crank is something special . Nobody uses the crank they are comparing to these days. That was abandoned long ago.

Second they say the speed carb uses bigger jets. It only has 1 jet and it is the same size as the stock nt.
The flakey fuel filter they show I have never seen in any of the kits I have bought form many different vendors.

On top of all that their are many vendors using better hardware these days as well as using 8mm mounting studs which the wildcat engine does not appear to have. Is their engine any good? I would say it's probably not much if any better than the one you have now.

Whenever some one is misleading or out right lying in their ad you should consider where else the bulls**t may lie. Just a heads up I have never heard of anyone using this vendor.

I stand corrected. There are reviews in the dealer review section of this site. I strongly recommend you read them.

Checking all this out it looks like they are using the runwell engine which is a pretty good engine, and is using the larger 8mm mounts.
The best way to buy it is through ebay with paypal. Then you have double the ability to seek help with ant problems with the order.
AUTHENTIC Wildcat™ PK80 Runwell 80cc/66cc Motorized Bike Kit Motor ENGINE ONLY | eBay

 

[Chainlube]

I think Californiabike and Gasbike are the same address, bottom of latrine.