tuned exhaust

[al6600]

ok a couple of questions feel free to answer as any help would great

first off the after reading the how to check my port timing its says
the port should open and close an equal angle either side of 0 deg but
my exhaust port seems to be about 5deg out to one side, should i modify
this to get maximum power or is it close enough.

second is the tuned exhaust designer makes my exhaust 539mm long is
that right and how come cars etc have short ones. also is beginning of
the pipe supposed to start at the engine block. ie if you use a
scilicone tube to attatch it would you deduct its length from the tuned
pipe.

and my last question ive read in a few places, that strimmer engines
have built in rev limiters in the coil to stop over reving as a
strimmer isnt under much load is this correct.

i know thats a lot of questions but thanks for taking time to read and
hopefully answer them


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al6600
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