porting ques

[adam833]

i have an 86 trx250r engine, if I go with an 87-89 OEM long rod crank and an 87-89 piston is the porting the same as an 86? WHat year cylinder would I need?
thx

[wilkin250r]

The change in rod length will have a small change in your port timing, but it's really not significant.


Any year cylinder will work. They all have slightly different ports, but they all behave pretty much the same, long rod or short rod.