Yamaha BWS Zuma 70cc Cylinder upgrade for more performance and power. Higher top speed!

I install a 70cc big bore cylinder kit for my Yamaha BWS. Can i break the 70kph barrier?

[@johndoe-xs4ph]

I just finished upgrading my zuma 50 to a 70cc with a new pipe, new variator, new shoe and clutch bell, up jetted and new air filter, after all that it now goes 80kmh knowing the crank arm is stock though I'm a little hesitant on riding it at 80 for long periods but oh man is it ever a blast.

[@BikePackingPleb]

Why did you mangle the original gasket? Whoever worked on that before this video put the head back on wrong, I can see where it was blowing out the side but the gasket was still good before you TORE it off the bike.

[@corneliussianturi476]

Seems Fun if you able to instal 63mm piston on it I mean, small stroke big piston daym, gonna rev really high with more power on it

[@ElvisVikic]

Bro love the mr2 and bike. Good taste

[@therealboofighter]

Thank you.

[@battshytkrazy156]

Nicely done

[@therealboofighter]

Thank you

[@bryandelatorre3391]

What’s the jet size? Running stock oil injection or premixing?

[@wahkitng4505]

For the 70cc upgrade . Do you need to upgrade the carburetor to.

[@richardjaramillo7087]

Was wording if you happen to blow the top end fairly quickly after the new jug and pistion were installed ? Noticed you didn't remove the ear on the c clip that holds the pistion pin in the pistion. Just speaking from a recent experience I hand rebuilding a yz85 stroke! I blew two top ends before I realized the ear on the c clip would brake off and jam between the cylinder and the pistion . Just was wondering if u had ran across the same issue C✅ G❌

[@therealboofighter]

That has not happened to me yet.

[@deanjollow2892]

Not any issues I’m thinking? Bulletproof? Same as always

[@therealboofighter]

The engine, no problem. Other issues yes.

[@deanjollow2892]

@@therealboofighter did you explore different slider weights for the out of the hole performance?

[@therealboofighter]

I did.

[@billywatkins64]

No heat cycling, no break in, just jump on and ride it like you stole it.... Hoping the kit holds up

[@therealboofighter]

Me too.

[@WickdPerfekT]

There are competing schools of thought for engine break in.

[@wahkitng4505]

What’s the jet size you put in

[@wahkitng4505]

Did you have to change carburetor too or just piston ring and head

[@therealboofighter]

I did not change the carb. Just the jetting.

[@wahkitng4505]

@@therealboofighter which jetty you get

[@wahkitng4505]

Can you. Do video on that one

[@therealboofighter]

I don’t think so. My scooter is down right now.

[@wahkitng4505]

my electric push start don't work what could be wrong.

[@dafamousgosse_poillue6702]

i have the same problem

[@wahkitng4505]

what brand kit is this and how much is it

[@therealboofighter]

Go to scootertunning.ca.

[@jwheeler770]

Did this exact same build same problem cannot tune carburetor anybody find a solution?

[@therealboofighter]

Do you mean that you don’t have jets?

[@s_macc1735]

It would of been way easier for you to just undo the motor from the frame

[@therealboofighter]

My life is all about find the easy way after I have already done the hard way.

[@johndoe-xs4ph]

@@therealboofighter Honestly the way you did it was the easier way lol, the other way requires a lot more labour.

[@wahkitng4505]

And my oil light something come on and off

[@joerivamonte3004]

Are you using stock carb? Did you change your jets?

[@therealboofighter]

Stock carb. Upped the jet a little.

[@fluzzz1545]

@@therealboofighter did you have to adjust your air fuel screw, im doing the same build right now and i can’t the tune right with stock carb

[@therealboofighter]

It’s hard. I need to spend more time with it.

[@fluzzz1545]

@@therealboofighter ya i just got mine yestersay and i’m having a hard ass time trying to tune it haven’t even got the chance to ride it correctly yet

[@hectorroig4933]

What is your top speed ?

[@Austinwolfaro]

u cant use that spark plug its way to short for that 70cc kit

[@therealboofighter]

Interesting, I didn’t know that. What would the symptoms be with running a short plug?

[@Austinwolfaro]

@@therealboofighter nothing i dont think it would harm anything just not as good as spark

[@therealboofighter]

Ok, I did run it this way for a bit and then it’s seams to have trouble getting back up to speed.

[@Austinwolfaro]

@@therealboofighter yea try the longer one or if u have one I don’t know the size but I know there longer

[@therealboofighter]

I will have to get one. Then wait till spring. It’s a snowy winter wonderland were I live