With a nice day i decided to break in My HPI Firestorm. I ran the heatcycle/traxxas method in the past with no issues. I even broke in my OS cvrx in my EVO 3 last week with no issues. Today I ran 2 half tank runs at no more than 1/4 throttle letting cool in between both. Then 2 half tanks at no more than 1/2 throttle letting cool in between. on these runs I only had to lean HSN 1/4 turn to maintain temps it the lower 200's. On my next two runs i go half throttle with full throttle mixed in. When it was time to tune the motor i leaned out to maintain smoke from pipe and temps in the 220-230 range. The problem when trying to hold full throttle or accelerate fast the motor would sputter and die if I did not let off. It seemed like a lean symptom so i richened and same thing happened and my temps dropped to low,I always had plenty of smoke. I also noticed fuel leaking from crankshaft when cleaning afterwards. could my HSN be to rich or lean? and is so witch one.

i think your plug is bad. happens durring break in ... i had this problem with my .18tz. no matter how i tuned it if i trottled it it would sputter and stall changed the plug and it ran just fine ... the oil leaking is not good. is it near the clutch or the exhaust? it its near the exhaust most likely a broken seal

Sounds just like a plug.

Sounds like you may need hotter glowplug and to check the seals and bearings on the crankshaft because if theyre leaking then it will definately affect your engine.

i tryed the plug but it was another cold plug. The oil leaking could have happened at beginning of break in before the bearing go sealed from heat, I only noticed a little after the day was over

It is so hard to tell what your problem is since you already trouble shot the most probable problem cause, the plug. (Of course, I hate break-in as far as plugs go, pluges become disposable items as the rich mixture destroys them. Spending $6-12 USD on plugs during break-in is annoying for me.)

Can you post a vid with sound of your RC as it is now? Also, run it up and down, some at idle, some at half trigger, and a full trigger pass at your current tune. This will give us an idea of if you are too lean, rich, and help us guess if an air leak at the carb, backplate, and/or bearing seal might be the issue.

i tryed a med plug today and ran like a champ for 4 tanks till sit stalled out and would not start again. I think the plug blew again. I was running it rich still. The oil leak stoped also