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Yamaha ty 250 boost bottle ?


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I have read some literature about the boost bottle and the main reason for mounting one is to collect the deflected air gas flow from the piston inside the crank. 

With mounted reeds this effect is much lowered thus the boost bottle will not have a big effect, but try it out and go ahead. 


If there is some effect please let me know. 

More effect would be installing a newer carb and newer reeds if you ask me. 

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I tried one on a 250 Rev 3.  It was quite a while ago but as I recall, it a produced a very smooth low end power.  The bike would pull to very low RPMs and would take large throttle openings at low RPMs.  Response was similar to a very small pick up with a 4 cylinder diesel engine.  Somewhere on the net was calculations or maybe recommendations on the appropriate volume.  

I believe I used a spacer between carb manifold and reeds to connect the bottle.  (I may have tried it before and after reeds.)  At the time someone suggested it was really the spacer having the effect but I don't know.  The Mikuni manifold was 1/2" shorter than the Keihin manifold.  I used the Mikuni manifold with spacer and Keihin so the overall length remained the same.        




Rev 3 Boost Bottle.JPG

Edited by mcman56
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I tried this boost bottle on 5th scale r-c buggies.  zero improvement at any rpm range.   Check this web site out.   www.thunder products. its in usa. They make a device that fits inside the carbs bore down stream from the carbs slide. Its called quad flow torque wing.  sorta hard for me to describe that it looks like here in words.  Its effect is dramatic off idle, low rpm-s.  much stronger power. The carb has to be leaned out- pilot jet only. Yes its spendy. but worth every penny once its installed, rejetted- pilot jet only and used.  I use one on a r-m 144 build, installed on a Kehin 36 mm air striker short body carb. Uncertan if this company makes the quad flow torque wing for the smaller carbs we have on our trials bikes.  agan-- www.thunderproducts,co.     have a good day everyone.

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