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Like the post says I’m new to this engine. I’m wondering what other engines are the same, BZM? Also any other names the engine goes by and just general info. Where can I buy replacement reeds? (Sorry in advance for the noob question) thanks!
 

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There are a few similar engines but none are the same. The polini 6.2 is a restricted 3 port engine with a 14mm carb to output 6.2hp. It's the next engine after the polini 4.2 for junior riders. There are water and aircooled versions available. Here you can see the schematics of the polini engines.


I have polini parts on stock and shipp them to usa.
 

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Discussion Starter · #3 ·
There are a few similar engines but none are the same. The polini 6.2 is a restricted 3 port engine with a 14mm carb to output 6.2hp. It's the next engine after the polini 4.2 for junior riders. There are water and aircooled versions available. Here you can see the schematics of the polini engines.


I have polini parts on stock and shipp them to usa.
thank you! So question.When people upgrade to a 50cc bmz head which I believe is 5 port, do they also upgrade the reed and carb as well? What would be a common size upgraded carb and reed for this engine?
 

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thank you! So question.When people upgrade to a 50cc bmz head which I believe is 5 port, do they also upgrade the reed and carb as well? What would be a common size upgraded carb and reed for this engine?
i dont think it would be worth it you would be better off just getting the bigger engine
thank you! So question.When people upgrade to a 50cc bmz head which I believe is 5 port, do they also upgrade the reed and carb as well? What would be a common size upgraded carb and reed for this engine?
im not 100% sure but i think it takes welding and machining to fit a big block cylinder onto a small block allso Bi Zeta (BZM) and Polini are two entirely different company's its like trying to take chevy parts and make them work on a ford...
 

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thank you! So question.When people upgrade to a 50cc bmz head which I believe is 5 port, do they also upgrade the reed and carb as well? What would be a common size upgraded carb and reed for this engine?
Yes you can make a upgrade, BZM had made cylinders that fit on the polini bottom end, they where available as 5 or 6port. If you want to upgrade, I recommend at least an 18mm(better 21mm) carburetor and a different exhaust(bzm race pipe 50cc). Reeds can be used the same.

Polini have also a 50cc cylinder that would fit.

My question is did you ever ride a pocketbike with an engine like the polini 6.2 or higher??
The 50cc BZM engine is a beast with over 15hp you need a track to run it, it's nothing for the neighborhood.

I've two engine with this 50cc setup for sell, here you can take a look on an engine with the BZM upgrade.

 

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I have a bzm 50cc 6 port with a 21carb. I recently got a 40cc cylinder for parking lot riding because the 50cc was too much and i don't go to a track often enough.
 

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I just bought a Elite 11 with the 6.2 and Blata 2.5 with the 4.2... These are my first euro bikes only had chinese before.
The 6.2 on first look need a new top end. I found the 36mm 5 port ac jug with piston and a new head in italy.
The 4.2 needs a flywheel and entire pull start assembly which I found in germany.
This stuff aint cheap but I'm looking forward to riding some real pocket bikes. Currently have a MTA with eBay crate motor and a few mods
 

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Blata 2.5 normally doesn't use a 4.2 engine. There is a own Blata 2.5 ac engine.
And why do you think that you will need a new top end? Post some pics and it will be easyer to help you. I also sell Polini, BZM and other Italian minimoto parts.
 

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Yeah, you must have an Blata Elite. The blata 2.5 and 2.6 frame do not have the same motor mounts. They mount a tool based engine, 39cc or like the Chinese 47cc and 49cc engines.
 

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Chrisi & ATVrunner2 I'm not sure what I have then. I thought he said the pink one on the left was a blata 2.5 with the 4.2 motor.. He did say the Chinese motor was a copy of that.... So what is the Pink bike, a blata 2.5 with what motor? What's that called please?

The red one he said was a blata elite 11 with the 6.2 motor and 5 port ac head. The motor for that bike was in a bucket in pieces when I bought it. I just slapped it together real quick bc I wanted to see what the bike looked like together and to make sure everything was there. The cyl jug and piston were scored so bad, looks like a ring broke and gouged it, I found a new 5 port ac jug and the cyl head cover piece in italy
159882
 

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The left one is a Blata 2.5 with the origin Blata ac engine have about 3hp. The right one is a Blata elite. If it's a 4.2 or a 6.2 I can tell you when you make a picture of the intake. There is the only difference between the 4.2 and the 6.2 engine from Polini. There are some numbers on the cylinder of the Polini if you tell me the numbers I can say you if it's a 3 or 5 port head.
 

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The left one is a Blata 2.5 with the origin Blata ac engine have about 3hp. The right one is a Blata elite. If it's a 4.2 or a 6.2 I can tell you when you make a picture of the intake. There is the only difference between the 4.2 and the 6.2 engine from Polini. There are some numbers on the cylinder of the Polini if you tell me the numbers I can say you if it's a 3 or 5 port head.
159885

Can you tell from this picture? Only 1 I have in my phone. I can take better pictures tomorrow
 

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Yes that's enough, it's definitely a Serie 2 crankcase. 3 port =6.2hp, 5 port ~ 10hp
For the 5 port cylinder I would recommend a bigger carb. 17mm or more and a good pipe.
 

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Yes!! Left or pink is Blata 2.5, a 39cc air cooled engine. 3.4hp, supposedly. They are peppy, rode a buddys, very fun.
And yes the right is definitely an air cooled either 4.2 or 6.2, like Chrisi said. My instant guess is 4.2, more common. But it is possible a 6.2. Chrisi would know better.
 

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Yes that's enough, it's definitely a Serie 2 crankcase. 3 port =6.2hp, 5 port ~ 10hp
For the 5 port cylinder I would recommend a bigger carb. 17mm or more and a good pipe.
Thank you again I don't know about these European bikes. Old owner claimed it was a 5-port head but it was damaged so bad I had to order a new one Polini p/n# 143.010.016 with cap p/n# 143.015.023.
It has the Dellorto 14/14L carb on it now, Could you recommend a carb please??

Can't wait to ride one of these bikes, never been on or owned a euro bike just china junk. If the bikes are as a powerful and fast as everyone says I may abandon the china bikes and never go back
 

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Thank you again I don't know about these European bikes. Old owner claimed it was a 5-port head but it was damaged so bad I had to order a new one Polini p/n# 143.010.016 with cap p/n# 143.015.023.
It has the Dellorto 14/14L carb on it now, Could you recommend a carb please??

Can't wait to ride one of these bikes, never been on or owned a euro bike just china junk. If the bikes are as a powerful and fast as everyone says I may abandon the china bikes and never go back
Most people onley ride china bikes because they are easy to come by there used to be plentiful supplies of parts but now that it's dried up and can only get engine and engine parts most hobby enthusiast are going to be shelling out buck$ for euro bikes .

On the other hand it's all in the beholder and I have plenty of crappy china bikes some I will never get rid of
 

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That's the right cylinderset. Carb you can use a phbn 17,5mm or a phbg 18mm. But you will need a other intake manifolder. I won't run the 5 port on a 14mm carb it's a big restriction and you go dangerous to get to lean.
 

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Most people onley ride china bikes because they are easy to come by there used to be plentiful supplies of parts but now that it's dried up and can only get engine and engine parts most hobby enthusiast are going to be shelling out buck$ for euro bikes .

On the other hand it's all in the beholder and I have plenty of crappy china bikes some I will never get rid of
I have 2 china bikes I'll keep to mess around on and let friends ride. I do like the satisfaction on improving power with the work done to it.
I understand you on the money for parts on the Euro bikes. I just dropped 1,500 on parts and probably still need another couple hundred lol $$$.
 
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