New SBT engine 657x break in and bog

[mstr54]

I just put a new sbt engine in my 94 xp and have a few questions about the break-in performance. I did put an oil block off kit on and I am running pre-mix. I am using SBT break-in oil at a ratio of 4 oz to every 1 gallon of fuel. I have the low speed set at 1 1/2 turns out and high speed at 0. I do have an R & D open flame arrestor, with MSD ignition wires. I took my Doo out to break it in for the first time and it seems to bog when I start to throttle up and will almost quit running. The higher the RPM, above 4000, it seems to run fine. Although I try not to run above 50% throttle because I am still trying to break the engine in on the first tank of gas.

I also had one issue with the engine overheating. The overheat buzzer never came on while I was running the machine. However, when I turned the engine off and then tried to start it again, it would not turn over and the buzzer alarm came on. I had to wait about 20-30 minutes before the engine would start up again and I also installed new spark plugs. The used plugs appeared to be wet and black on the tips as well as the first 2-3 threads of the plug.

My question is does this sound normal for the performance at break-in. I understand the fuel mixture is richer than it will be for the next tank fill. Could this be causing the bogging down low and the plugs to be fouling. Thanks in advance.

[Technical Support]

Re: New SBT engine 657x break in and bog

You can not run the stock screw settings for aftermarket equipment. I don't know if your carbs have been properly rejetted for your R&D filter, or where your needles need to be. I would ask Bill O'Neal on www.pwctoday.com about that.

That's not typical overheat behavior. I would be more inclined to think your battery is on the way out. Measure the cranking voltage, make sure it doesn't drop below 12.5V