You have air in the system. Did you bleed the coolant system? The bleed screw is on the front of the head above the header. You need to crack that a couple of times to get the air out.

 

x2

air in system

putting front end in air will help a little but won't always get rid of all the air

 

Do NOT do the heat up, cool off, heat up, cool off. All you're doing is glazing the rings and not seating squat. It's actually one of the worse things you can do to a new motor. You'll end up with low compression, higher oil usage, less hp, an unhappy powerplant.

You need to heat it up to operating temps and then FLOG THE LIVING CRAP OUT OF IT - after you get the air outta the system.

To properly seat the rings you need to get them to temp AND have higher pressures found with WFO running. The gasses actually travel over the top of the ring and into the recesses the rings sit in, forcing the rings out, thus helping seat the rings to the cylinder. Just letting it come up to temp and then letting it cool off doesn't do squat.

Time and time again, I've seen a huge difference between the heat cycle stuff and the heat and flog and the heat and flog ALWAYS produces a better engine.

When I was involved with racing Superbikes back in the 80's, we'd build our engines and then take them to the dyno. The very first time they were fired up, it was heat to temp and then do dyno pulls. The engines that we heat cycled first were always down on HP and always used more oil. It only took us four or five runs before we started verifying the heat and flog method was much better.

Here - this guy explains it very, very well: Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

 

Kfab I have always done heat cycles on all of my engines, but I then drive it like I stole it afterward to get it to properly seat the rings. The guy who screwed me on my engine gave the recommendation of 3 heat cycles then go beat on it. After my disappointment from a known vendor on here, I took matters into my own hands, rebuilt the engine with a friend, and learned a lot about how these engines work and should be assembled, and got it correct. It amazes me the corners people cut for profit.

Moral of the story is do these things yourself because no one looks out for you better than you.

 

Agreed!

But you also have to realize that there are people out there that shouldn't be allowed to even try and use a screw driver... We're some of the lucky ones that have some mechanical ability.