Drilling Boyesen Ports in a YT175/Blaster cylinder

Simple video on drilling boyesen ports in a 1983 YT175 cylinder.

[@RubberSalt]

They allow more flow to the bottom end. They also dont quit flowing when the piston covers the port. On the down stroke, they allow the fuel /air to fill the intake and out the transfer port next to the reeds. Youll see them on ALL the dirt bikes out there, snow mobiles, etc. They are good stuff.

[@HamBone86]

Does drilling the holes sacrifice top end power?

[@RubberSalt]

@@HamBone86 Almlows for more top end

[@RubberSalt]

@@HamBone86 Negative. It actually benefits top end power. The angle of port does play into power delivery. A port that flows in straighter will favor higher RPM. Ports that flow more towards the bottom of the transfers favor more mid range. Ports need to have sharp edges in the transfers.

[@phodailey]

Gotta love the extra power

[@denniswilder3014]

Any jetting change after doing this.or does it make it picky or peeky power curve.

[@RubberSalt]

You should definitely check your jetting after. It improves the mid and upper range power the most

[@oblixerated]

what other engine fits this frame?

[@oblixerated]

what do boyesen ports do?

[@shoominati23]

Will that fit onto a DT 175?

[@RubberSalt]

shoominati23 they probably will. Im not familiar with the dt175 top end.

[@getawaywithchen1929]

what is the advantage of drilling this holes?

[@harisivanandhks3906]

It gives more fuel flow to the engine and gives more power

[@goodfellasinc.5648]

Not shit when you port them right to begin with

[@RubberSalt]

@@goodfellasinc.5648 They help flow more mid and top end power. If you look at any modern high performance engine with reeds on the cylinder, you'll see them. Adding these is part of porting them right.

[@jcwar6753]

@@RubberSalt so can you do this to pretty much any 2-stroke?

[@RubberSalt]

@@jcwar6753 Only those with reed/disc intakes on the jug. Piston port or case induction wont work

[@gilsongonzalez4011]

espanish???

[@RubberSalt]

@digschopper Wish i made a video of the pipe i built for this YT :) search "pipe design" on 3wheelerworld

[@yantoyanto4071]

Pungsinya apaan itu