i put my z400 in the shop put a new piston kit, timing chain, spark plug, oil filter, crankshaft bearings, new complete gasket kit but a used crankshaft do i have to break it in again if so how do i break it in and how long does it take sorry for being dunce any help is appreciated? Thanks

 

theres a few different ways you can break it in...some people do things differently but what i usually do with 4 strokes is when its a new rebuild top or bottom or both is i just take it easy at first i wont go past 50% throttle for about....6-12 hours of ride time....then i do an early oil change after the first initial little easy going break in process then after that i will run it at 75% or so then 6-12 hours of ride time i make another oil change and little checkup on valve lash and whatever then after that im usually ready to starting running her hard...i know it kinda sucks cause you want to just say screw it and get into it like WIDE OPEN like a few hours after rebuild but i just wait it out and take it easy and slowly progress further with the bike, i give it some good time to break-in, alot of people do it differently its kinda preference some people maybe only take it easy first few rides then change oil and thats it, whatever you decide to do make sure you kinda just take it easy at first and kinda pamper it and give an early oil change before you rip into it at the least.

 

False, DO NOT BABY YOUR MOTOR.

Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

 

False, DO NOT BABY YOUR MOTOR.

Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

 

Follow the MotoMan, and your engine will thank you. You don't give it a good beat down, but you really shouldn't baby them either. The engine needs to be loaded an accel and decel to seat those rings.

 

its not always the case to run it hard when you break it in... not every bike is the same...........i dare you to do that on some 2 strokes, way i break in 2 strokes is let it sit at a high idle with a big fan blowing at it or...let it idle while in the back of a truck driving somewhere like the race track or something, theres most likely gonna be alot of arguements on "The correct break in method" but its kinda personal choice, read a factory manual one time and see how they say to break it in lol, you wont hit full throttle for the first months of riding the way the manual says...

 

First of all, I rode 2 strokes for the first 23 of my 26 years of riding. I know how to break in a 2 stroke, but we're talking about 4 strokes.

The reason the manual says that is so they don't have people buying quads and blowing the motor the first day because they were bouncing off the rev limiter. They are covering their asses. Believe me, there is a difference in motor power between the 2 methods.

 

The manual says that so they dont go riding WOT right away and bouncing off the rev limiter sure....to cover there *** yea pretty much, which is why you dont break some quads in hard like that,why do you think that parts in there, plus its safer anyways, specially when straight from the crate...i used to work at a yamaha/suzuki dealer and when you first start those engines for the first time it has the funniest smell almost like a sweet smell...no other smell like it, its the newly started engine smell lol, and my first 2 stroke bike was a 76 cr250m elsinore and yes i have extensive experience with 2 strokes also, if you wanna go full out on a brand new engine with components that havent even had much time on it...then go for it, somebikes this is ok to do....some its not, most people beat the **** outta there bikes anyways so whats it matter just break it in how you want then.

 

the motoman technique applies to 2 stroke too, and i swear by it for EVERYTHING

 

BAD BAD BAD!!!

you should NEVER keep a fresh engine at ANY constant speed, fresh rings need varying crankcase pressure/vacuum (only attainable by rpm modulation) to seat properly.