Today i finally got my new KFX 400 and wanted tips on the BEST way to break it in.

 

Ride it like you're gonna ride it without keeping it WOT for and length of time. Never keep the throttle constant. The rings need cylinder pressure to seat them against the cylinder walls. Cylinder pressure stops at the rings and goes in behind the rings and pushes outward to form a perfect seal. You do not get good ring seating by riding like a baby for the first while because cylinder pressures are low. I've built numerous engines from 1/4 mile to lawnmower and have treated them all the same. Never have I had a break in problem or a bad set of rings. I personally do not believe in "breaking in" anything but camshafts, but camshafts in an assembly line engine are good to go before it hits the showroom floor.

 

Camo, you say you break in cam shafts. This caught my attention because im doing that project this weekend. what type of break in are we talking? Same as new quad?

 

Thanks a lot for the info. Its nice to know i dont have to ride like a panzy for the first 5 hours.

 

Ride it slow and easy for the first 10 hours dont rev it out and beat on it. I took it easy on my quad and rode it juts like i said and my friend beat on his and mine runs so much better than his quad[img]i/expressions/face-icon-small-wink.gif[/img]

 

yea take it easy for the first ten hrs, dont baby it, but dont just rip into it, I broke my Z in taking it easy and two yrs later it still runs just as good

 

Check out this site Break in Secrets pretty much goes with what camo said. Good Luck!![img]i/expressions/face-icon-small-wink.gif[/img]

 

If I was you I would take it easy the first couple of hours.No more than half trottle. It says in the manuel how long you should only run half trottle.I ran mine no more than half trottle for about 4-5 hours before I gave it more.Even then I still didn't floor it for a while.When I put the Thumper 470 kit in Gary told me not to gun it for a couple of days.Thats what I would do just because its better to be safe than sorry.

 

Don't ride it like a pansy. Don't hold it WOT for any length of time. Bounce the RPM around constantly.

 

About the Camshaft break in.... During final assembly make sure all your vave train including cams have a liberal coat of "break in lube - comes in various cans and manufactures" . Upon start up, do your usual engine checks and make sure it's running well. Rev it up above 1200 RPM - usually I go 1800 - 2000 - 1500 - 1800RPM and hold it in that range for 20 mins. Camshafts and their mating components need higher RPM during break in to reduce the rolling friction. If the RPM is too low or inadequate lube, you will wipe out a cam lobe.