yar those two bolts in head are i think 9 number .. do u konow how to set timing ? if u remove them u will f the timing... if u cannot adjust valve timing , valve lash(jisa tappet adjustment bolthay hai ya valve adjustment bhi kahtha hai) ...then absolutly dont go ... one wrong adjustment and ur engine either seized or blown..
u can use a ghotti of that number and a handle .. will 90+35 ... try these things from gawalmandi rawalpindi.. there is a shop which i dont remember but that has all bike tools .. and rates are also reasonable..
porting is done to increase amount of airflow.. increasing will not help necessarily.. however u can polish exhaust port and dont worry too much with its widening .. .. which kharadia will u do this work from ? i liked mohamadi kharadia .. committe chowk .. did used his services for 2 or 3 of my friends bikes overhaul...
post the pics of carb .. both sides which attach to filter and engine side..... is it labelled pz22 ? u may be able to use it.. but u will need re jetting .. main jet 2 step bara lagana hoga.. and u may play with the slide needle.. of carb.
hay bhagwaaaann.. ya 2.3cm tho chonda/honda ka valve ka size hotha ha... our tum itna our kholna chahtay ho ?
if u go with widening the ports then 2-3mm is max u can safely do.. do 1 mm less for exhaust.. say if u increased the "diameter" of he inlet port by 3mm then exhaust should be widened by 2mm..
bernoulli isnt so simple phenomenon... because it starts all at air filter.. then throug intake port of carb and then the venturi of carb then the out port of carb then through the manifold pipe then through the intake port ..so there are a lot of regions where the dia is increased/decreased.... and also the air fuel mixture wont be free flowing .. the will be sucked by piston further complicating guessing bernouli principle..
long and short many people do porting .. whereby they increase port diameters and also polish the exhaust port for mirror smoth surface.. and roughen up the intake port for better atomization of fuel/air mixture..for complete burn.. remember exhaust is poished and intake is roughened..