porting the 66cc

[battery]

ok so im dis assembling my engine to give the insides a look at 1,000 miles and put it on a new 29" I am looking to widen the ports a mm or so. I still have port valve no reed valve for me. can anyone tell me the do's and dont's. how much can I shave in width? or should I?

 

[Deleted member 12676]

the most benefit to be had is widening the intake port. also take 1mm off the piston skirt at the intake side.
widening the exhaust port gives more top end power while giving less low rpm power.
you can widen the transfers toward the rear 2mm.
increase cylinder compression while you're at it.

 

[Deleted member 12676]

extended intake is DIY although buying their zigzag manifold does extend it some.
if you don't have the Jaguar CDI then just plane the head and cylinder mating surfaces for a better seal. Without my CDI the higher compression is hard on the bearings.
widening the intake just gives the engine a bit more power. with too little power you have to scream the engine more and slip the clutch more when taking off which shortens the life of the engine.

 

[battery]

Last question, Would you happen to know if the Racing carb from jnm comes with the longer offset intake? It mentions it in the parts list, but is not %100 clear.

 

[battery]

unfortunatly the jaguar cdi was out of stock :/ but I ordered it. Fingers crossed they get in soon! I will do the porting and shaving when it comes in.

 

[Deleted member 12676]

the CDIs will be in stock in 10 days.
best to ask JNM about the intake.

 

[battery]

SWEET! and thank you i tried to call but no answer. I'll try again or email if that doesnt work.