First, let me start off by saying these are great mills, I have 3 of them, two CRF 3 port and one CRF 5 port. Most who have been in the hobby for some time have there own break in procedure, which is fine, most have something that works for them. I thought I would give a little insight as to what we recommend for pre heating temps and break in temps.

Break in: Pre heat to 180 F before firing. 180 F is enough heat to allow the materials to expand properly and relieve the stress on critical components i.e. piston, con rod and crank thats created by mechanical pinch and tight tolerances. Once the engine is started let it build it's own temp to around 200 F. I will leave the Comp Heater (or heat gun if you don't have one) on the head to assist in keeping the temp at 200 F until I have run enough tanks through and leaned the engine to where it can maintain 200 F minimum on it's own. I break in my engines in the buggy/truggy in a parking lot where I can hear what the engine is doing and monitor it properly. I will pre heat my engines to 180 F for the first two gallons before starting, after two gallons 160-180 F is plenty, the engine will fire instantly, is easier to tune and will save you fuel, not to mention increased engine life and performance.

I wouldn't say they like to run hot. Mine with a nice crisp tune comes in around 230-240, 250 happens..

When did it drop?
We had one 5P CK engine here go through four gallons before it dropped. Seems extreme to me?

Using only Byron Prodriver 25% with 9% oil BTW.

Mine dropped right after the 1 gallon mark.. It still needs leaning from time to time, so I don't think it is fully dropped yet.. I'm just under 2 gallons on it..

Both my Orions (CRF and Discovery) ran over 240 regardless of ambient temp until it fully loosened up. It wasnt surprising to see 250 running rich on a 70 degree day.

Now fully broke in its 230 in 100degree ambient.

+1 same here

Maybe mine isn't fully broke-in then? Awesome.. I don't temp much, but what I have done they seem to come off 240-250 pretty consistantly.

Quick question for some of you guys, What have you all done to get rid of the mid range bog? I have awesome off the line, and sweet top end, but my transition point sometimes, wants to cough and sputter. Mike Jackson, local Orion guy, has suggested O'Donnell 77T, which I think I will try. I drove his CRF 3 port Sat, and his mid bog is gone. Mine isn't quite a crisp as Mikes, I am running OD 97T. Anyone else running into this problem?

I run od97 and i dont have that problem.Maybe balance between high and low needles.Richen the low one hour and lean one hour on the top see if it changes if not try the other way.Lean the low one hour and richen the top one hour allways small changes.Work your way slowly:nod:

My Low end might be a little rich, because when looking at my idle gap yesterday I noticed it was ope more then I thought it was.. I really haven't set it like it should be, so I guess I better get it done..

i find that mine like a pretty crisp low end, even after idling for quite some time. They seemed to prefer a slightly leaner low end that i was accustomed to tuning to when i ran my OS, picco, and OPS motors. It caught me out at the PNB cause i had two rich low-end related flame outs after pitstops possibly costing me the win in Sportsman 1/8(still got 3rd after running out of fuel on the last lap). But once i learned and tinkered with them more, i changed my ways and got it right.

Even on cold starts, my low end is still rather crisp before it comes up to temp, only the high end seeming rich, but once up to temp, its smooth as butter through all phases of the throttle transition.

Also running OD 97T plugs + 30%

Once you start getting close to the ideal tune, the adjustment window gets SMALL, like 1/32nd to 1/16th adjustments to make very noticeable changes on the low end, but once its there, i have yet to have to retune in months.

+1 that as my orion act as you said when you get close the tune window gets small for peak preformance. Once there you dont really need to touch the needles 240 to 250 seems for me the sweet spot.I dont tune to temp but when its running at peak it seems to temp there.:nod:

Sorry im a couple days late on my post...I bought a cody king limited edition motor/pipe combo and its broke in enough to run it now and man does it have some low end balls...acually it pulls through intire power band..I couldn't be happy diffently worth the cash.....I was runnin a max power mq5 (or something like that im at work so can't look at it) not that the max power was a dog but it doesn't have the balls this cody king monsters got....so just like to say ty team orion for a bad ass piece
dnf don

Finished breakin in my mte .21. I was running 10.45 empty tank but still really rich. Should get easy 12mins with a full race tune. What plugs are you guys running. I am running os p4

Hi Scottym or pitpop

you helped me some posts back so i loved my CRF 5PORT ABI with 2057n pipe and extension, so the questios is i only run 1 galon or little more, the engine still perfect but im afraid the engine has not any pinch, i can move the flywheel so easy, its like a old engine sooo free... i is a characterist for this motor or mine wear out faster?(important to say the engine still running perfect) i dint nothing wrong no dirt inside all time new filters with oil, not run too lean.... , i take care the engine before and after breaking like a baby, i m just asking if its a characterisc for this motor be sooooooooo free after breaking

thanks
a lot

The motor pinch should be gone when the motor is broke in. If you are talking compression then have you ran it too hot? I have 2 orion one with little over 3 gals on it and still have great compression and one with 1 1/2 gals on it and cant turn it over by hand. if it runs good i would run it until it tells you in needs pinched( flameouts, wont idle, Etc...)