were you chasing the tune throughout the entire first quart of break in? I could not get up on the pipe at all without flaming out for the first 10 tanks of fuel, no matter what tune I had on it.

I had no trouble at all breaking in this engine. It did take longer than other engines I've had. I didn't use the break-in shim, I wanted to, but the first head bolt I tried to remove I stripped the head hex. My fault, worn wrench.
I have a dual motor starter box, I'm sure that helped. I just made sure that the engine was hot enough before I started it. I had to drain the pipe after every tank as it was full of spent fuel and oil. I think the JP-4 is a good pipe for break-in because it is a gas hog.

Here's a link to the GTR 2 in a MBX6-T just before it dropped it's nuts (still rich) on our new layout. Not my best laps, still learning the new track with a new surface. I start out 3rd, take second for a little while, and end up 3rd of 3 or last. The other two guys are 2 of the fastest 3 at the club, I'm still learning!
http://www.youtube.com/watch?v=CV8PCfF5We4
Cheers
Brian

Not at all, but I fattened it up, put on the comp heat and gave it a large idle gap. If it was below 220 I would lean it a little. It does change from 200 to 250 and will try to flame.

well between last night and this morning I was able to get another 8 tanks of fuel through it. I caved in and swapped the carb for a Werks carb and that made all the difference for me. The engine went from a PITA to a dream. Idle became steady, engine temps were not all over the place and I was able to get through all 8 tanks with the same tune and no flame outs. Had no trouble getting up on the pipe even rich and it was like a whole different engine! I am both happy and sad, but I really think the carb is just too sensitive to temperature and will vaporize the fuel when the engine gets up to running temps. The stock carb was temping at the same temp as the engine The Werks carb has a much better insulator on it and was consistently 50-75 degrees cooler which made all the tuning issues go away. I have almost 1/2 gallon through the engine now and its coming to life and I'm loving it. Going to finish up the last quart of break in fuel and then switch to powermaster 30% with 9% oil. One more quart of that and I'll be racing this engine a week from tomorrow.

You must had a lil air leak. i have broke in 2 and they ran like tops from first breakin. I have found that the mid needle needs to be leaned in an 1/2 to an hour. depends on the motor. mid range at two o'clock is money

+1 if using a small restrictor 6mm/6.5 mm.

Apparently that leak was somewhere in the carb. I spoke in length with Arrow USA today and over 200 of these engines have been sold and only 2-3 reported issues. It may be something stupid in the carb but I didnt want to be bothered taking it apart. The engine is just money now and even with less than 2 quarts, break in fuel and the added head shim its very smooth with lots of power. I'm not complaining at all since I had lots of spare carbs. I feel its more important for me to give factual findings since I am a dealer, other than just posting all the good stuff and none of the negatives. I do the same thing with Agama. i try not to blow smoke up peoples butts like allot of the fanboys do.

I dont use a restrictor for engine break in. I like to be able to see the idle gap.

I do appreciate the info though from both of you and maybe I will give the stock carb another try after a tear down and inspection and also tweek the MSN if needed.

has anyone tried running this engine with a werks 5 or 077t plug? wana use it with 25% nitro x for break in.

What clutch system and clutch springs are you running on your Arrow with the truggy?? thanks

This is just my opinion but the Werks plugs did not work in this engine. I am not bashing werks because I love werks but their plug is not for this engine. It would not run right. went back to a OS P3 and it was good.

Now since we are all friends here I will say that since I switched to a werks carb this motor is dialed.

Besides os what othet plugs are suitable?

Better stick to OS plug

this engine is a os clone. os plug is better

I have a brand NEW Arrow GTR version 2 sealed in box, selling for $150, will ship for free. PAYPAL Payment only

Hey Lee,

I just put a stock Mugen clutch on it for the break-in, with 3 .95 springs, I'd like to try a BUKU clutch next. I've got the M2C four shoe alum flywheel adjustable weight on two of my other engines, a Werks B6 pro and a Werks B2.
After she's fully broken-in, I may have to try a Werks carb and see if I notice any difference.

After trying the Werks 2013 pipe tomorrow, I also want to try using a progressive set of clutch springs, I'll start with a .9, then a .95, and then a 1.0. Trying to achieve a clutch that performs like the BUKU clutch.

BTW, I used a qt. of Powermaster Golden Break-in fuel, then the last three tanks I mixed in a third of Powermaster 30%, then half, then two thirds. It took about a little over a gallon to lose the cold pinch.
Cheers
Brian