needbout350
Member
Hey everyone noob here please forgive me if I am asking a question already discussed. I searched but either don’t know the right key words or couldn’t find what I think I needed.
I am getting into mini bike riding as a hobby with my kids and am working on my first engine build.
I have a non hemi gen 3 predator that has been run for about 45 hours in stock form with the governer. I am wanting more power for wheelies and general putting around. I’ve recently done some modifications (about 5 hours with governer removed, intake/header, billet flywheel, and 18lb springs) and am looking to take it to the next step.
I want to add a mod2 cam (is this a good choice?), flat top piston (.570 compression height), +0.020 arc rod, .670 boar stock appearing carb with low jet, e tube and bigger main jet, and maybe 1.1 raitio rockers. I may try to port/debur the head as well.
I’ll be dropping the gear raitio to turn about 5500-6500rpm. I’m currently using a tav2 2.5k engagement with a 10t and 50t sprocket for 5:1 raito hitting about 4000-4200rpm. I’ll be going to a 60t sprocket 3.1k engagement and shooting for 40ish mph.
Given that my engine has roughly 50h on it will I need to hone/boar the block for the new piston? Should I be concerned about the crank journal?
I’m also considering only adding the cam, carb and rockers if the block/journal are too far gone. Then running until the stock rod goes pop and starting with a fresh block.
What do you guys think? Will my mods get me where I want? Should I get the piston and rod or leave them out for now.
Sorry for the long post and thank you for any input.
I am getting into mini bike riding as a hobby with my kids and am working on my first engine build.
I have a non hemi gen 3 predator that has been run for about 45 hours in stock form with the governer. I am wanting more power for wheelies and general putting around. I’ve recently done some modifications (about 5 hours with governer removed, intake/header, billet flywheel, and 18lb springs) and am looking to take it to the next step.
I want to add a mod2 cam (is this a good choice?), flat top piston (.570 compression height), +0.020 arc rod, .670 boar stock appearing carb with low jet, e tube and bigger main jet, and maybe 1.1 raitio rockers. I may try to port/debur the head as well.
I’ll be dropping the gear raitio to turn about 5500-6500rpm. I’m currently using a tav2 2.5k engagement with a 10t and 50t sprocket for 5:1 raito hitting about 4000-4200rpm. I’ll be going to a 60t sprocket 3.1k engagement and shooting for 40ish mph.
Given that my engine has roughly 50h on it will I need to hone/boar the block for the new piston? Should I be concerned about the crank journal?
I’m also considering only adding the cam, carb and rockers if the block/journal are too far gone. Then running until the stock rod goes pop and starting with a fresh block.
What do you guys think? Will my mods get me where I want? Should I get the piston and rod or leave them out for now.
Sorry for the long post and thank you for any input.