How to tell a motor if it's 66/72cc, by not measuring it in person?

[Spare_Parts]

This seams a good deal from a great vendor. They also sell Zeda engines.
https://bicyclemotorworks.com/product/pk80-by-runwell/

 

[crassius]

This seams a good deal from a great vendor. They also sell Zeda engines.
https://bicyclemotorworks.com/product/pk80-by-runwell/

the one in the link claims performance parts that I don't see (except the stupid spring tensioner that is crap) price seems high (esp when ebay whole kits are $99)

here at the shop, I sell the CDH A80 (once called PK80, now called superhawk) for $80 exchange or $90 outright

 

[gary55]

Thanks. So how big is this one? Only way finding out is emailing? Or how?

https://www.gasbike.net/collections/engines-only/products/jet-66cc-80cc-bicycle-engine-kit

The ones I got from them like that are no mark rods. That makes them a short rod long stroke engine. 69.4cc.

 

[Vikingimike01]

This seams a good deal from a great vendor. They also sell Zeda engines.
https://bicyclemotorworks.com/product/pk80-by-runwell/

Thanks, is this one truly 70cc, or just 66cc? It looks like a great deal too.

It's a regular 66cc the 80cc is just a chinese label kinda like mph-kph. It's not 70cc I guess you could round it up to that though. I would just make sure you don't get one with cheese bolts. Get one with allen heads they strip alot less and the thicker mount studs too. I would get a silver engine too. Because the black ones are usually painted wrong as in inside the ports and crap and on the bottom of the cylinder head thats no good. The pk80 that umoto sells on ebay is a good engine heres a kit you can also buy just the engine for $99 I don't really like how much shipping is though. https://m.ebay.com/itm/DIY-2-STROKE-HIGHEST-POWER-PK80-66CC-80CC-MOTORIZED-BIKE-ENGINE-KIT/122598798446?epid=15005379696&hash=item1c8b75346e:g:OHwAAOSwIWVY-ob0&_nkw=umoto+pk80&_from=R40&rt=nc&_trksid=p2380057.m4084.l1313.TR1.TRC0.A0.H0.Xumoto.TRS0

They don't ship here, but thanks anyways.

 

[Bars]

Thanks. I didn't find any engine only kits there, wich is the thing I'm looking for.

https://www.gasbike.net/collections/engines-only/products/jet-66cc-80cc-bicycle-engine-kit

Is this engine 66 or 70cc? I didn't find it. Should I e-mail them?

There are no 70 cc 2 stroke engines, they are called 66/80 cc,the 66cc is USA measurements and the 80 cc are Chinese measurements, so it's a 66 cc engine,the PK 80 and the Zeda 80's are 69.4 CC's, I prefer the Zeda 80's over the PK 80, I have both and the Zeda will go 45 mph with a 40 tooth rear sprocket and the PK 80 only about 35 mph, but the seeutec PK 80 top speed is 42 mph.

 

[Will'smotobikes19]

This one is only 68cc and it has a 48mm iron sleeved cylinder. I guess the reason the Chinese call it a 80cc or some other dumb numbers is they count the combustion chamber on the head. Now if it’s a 40mm stroke it is different than the 38mm which this one is but not by much. If the 3mm stroker

crank had worked with the pk80 I have it would be 74cc but this cylinder was meant for the 38mm stroke engine.

 

[gary55]

This one is only 68cc and it has a 48mm iron sleeved cylinder. I guess the reason the Chinese call it a 80cc or some other dumb numbers is they count the combustion chamber on the head. Now if it’s a 40mm stroke it is different than the 38mm which this one is but not by much. If the 3mm strokerView attachment 84031 crank had worked with the pk80 I have it would be 74cc but this cylinder was meant for the 38mm stroke engine.

24x24x3.14x40div. 1000=72.3456. 48mm bore 40mm stroke 72cc disp. With 38mm stroke 68.72 so would be considered a 69cc.

 

[crassius]

48mm bore is rare - for others, the significant diff is 38/40 stroke - ignore cc's and get a 40mm stroke motor