hello,

i have a Yamaha Spy/MBK next, minarelli vertical engine. i can wheelie as long as i want straight ahead. the fuel will flow from my tank into my carb. that's no problem.

but if i make a 12 o clock scraper, my engine shuts down in 3 seconds. everything on it is original, but i tried different thing, bigger carb, turn the carb left in the mainfold. if i do the last thing. it will run 5 seconds longer...

does any one have a sollution how to keep my engine running all the time while doing a 12 o clock?

greetz, Sebastiaan

yes, i already saw that.... didnt try it yet...

but my main question is, can your carb stil suck fuel into the mainfold? my carb is like this: ---- (horizontal) when my scooter stands 12 o clock.

how do you keep it running... because on 12 oclock position the spray-nozzle, cant suck the fuel into the mainfold. thats why the engine shuts down in maximum 15 seconds. and in that shorty period of time cant your fuel cup (that thing at the bottem of your carb, with the fuel in it) be empty....

so, if anyone has some suggestions, please let them know...

greetz, Sebastiaan

well thats why u have 45˙ mainfold...


thats setup i use on mine... and i good 30-40 sex time to play on 12 bar...enough for nice burnout and more than enough time for bar scraping and stuff...

yes, about that 45 mainfold i know, maybe that will work @ minarelli horizontal and piaggio engines... but appearently you dont know how a minarelli vertical engine looks like...

quite a lot "stunt scooters" have this engine original...

mbk stunt/yamah slider
mbk booster
mbk next/ yamaha spy.

so on that engine is no other mainfold possilble....


do you now have a proper answer??

so you got 10-15 sec before engine shuts down?

when did you see someone that long on bar anywayz =)


no really... dont have any ideas in my head now... i would need enginein front of my self to figure somethingout... i'll go to neighbours spy to look it out...

yes thats right.

Andreas Gustafsson did a long 12, standing on his handle bars, but that is a horizontal engine...

OWT has some vertical engines, en they can also make long 12 burns ect...

Waynder wrote (View Post): › so you got 10-15 sec before engine shuts down? when did you see someone that long on bar anywayz =) no really... dont have any ideas in my head now... i would need enginein front of my self to figure somethingout... i'll go to neighbours spy to look it out...

Here is a pic of my minarelli vertical engine. Maybe now you can imagine how the thing looks like.
Bmxtreem: i would try to rotate the carburator for about 40 degrees in leftt direction. It should still work and when doing 12clock it wont be totally horizontal.





And here one example what to do with a "destroyed" cylinder



Take care

is it possible to put a carb from a motor-saw on the scooter?
cuz it works with membrans so it works in every position...
i have never opened a motor-saw's engine so i don't know if it is possible...
if not can someone explain why?

Overman wrote (View Post): › Bmxtreem: i would try to rotate the carburator for about 40 degrees in leftt direction. It should still work and when doing 12clock it wont be totally horizontal.

well that makes sence... why dont you try that? damn this engine looks perfect for stunting... expecially carburator...

Moving the carb for sure will solve many problems, but after a while you will need more fuel. Fuel pump or move the tank!

robbii2031 wrote (View Post): › is it possible to put a carb from a motor-saw on the scooter? cuz it works with membrans so it works in every position... i have never opened a motor-saw's engine so i don't know if it is possible... if not can someone explain why?

i opened once motor-saw engine, from that motor-saw carb was different than the scoot's, and that one could not be fitted cause it doesn't has that part that goes into manifold and the one that goes to air filter, but there are probably some different carb's that could go on scoot but they are usually too small because motor-saw usually has only 30cc and doesn't need to much of gas and beacuse of that it wouldn't work well, if you understand what i want to say

The carb you are referring to is a diaphragm carb, commonly used on go karts.

Tillotson would make an ideal carb for stunting, and you can allways modify a carb to mount with a rubber spigot.

eel wrote (View Post): › The carb you are referring to is a diaphragm carb, commonly used on go karts. Tillotson would make an ideal carb for stunting, and you can allways modify a carb to mount with a rubber spigot.

yup... we experimented with carbs from shtil chainsaw =) its not really that simple as it sounds... and take into considoration that we can mod existing parts on scoot to make it work 30+ sec on 12 bar wich is more than enough for any 12 stunt or more bigger burn...

+ u'll get reserve jets and other parts more easly


but in future... if someone has more time... im willing to give it a 2nd shoot... just to see how it will work in long term...

i know it's old topic...but...on my Slider as long as you keep the throttle on it won't shut down...also minarelli vertical...but, mine is not exactly standing on 12 o'clock...but if you don't have the throttle on it will shut and the fuel starts leaking...but it's not a problem when you are burning tires or scraping...