If anything you would need a new piston, sleeve and conrod set (not a new head button). BUT, running a little too lean for a couple of tanks SHOULDN'T do much damage, but just periodically check your compression. If you can easily turn the engine over when it's cold - even if you only have to use a tiny bit of force could be a bad sign. You can also try the "3:15 test". This is where you take your engine out of your car, take the pipe and manifold off too. Then, turn the flywheel anti-clockwise until you reach TDC, and then let the cooling head fall to your right (which will try to turn the flywheel/crankshaft anti-clockwise). If your engine turns over after any less than 10 seconds, you are running very low on compression, and you will not have the same performance you once did.

Imo is more tuning issues, carb out of balance

Definitely.

I think you guys are right. The real problem is I just dont have enough time for consistent use in this hobby right now. After work Im always fighting daylight and cramming enough time in to get to destination, heat the engine get everything situated, drive the engien a bit and saturate the engine, then start tuning. By the time its running pretty good I dont have enough daylight to test it for optimal tune!! UUUGHGHGH lol

Im pretty close now, today ill just go by the tuning bible, the first 3 steps under the tuning section. Its basically wat i do but this wat should be a little quicker. I'll make sure the pinch test is dialed in for about 6 seconds to die, make sure the idle is good and steady then start tuning. I tried 40% the other day with this drag mod and it was fast but not optimized with tune and shims im sure. It ran too strong and I didnt like how high the rpms got, not really necessary for an everyday basher like me

Next week a few new parts comin in that I think will help the tune even more
New line, new high quality bell/bearings and a new 2058 pipe
I gotta say tho, I am loving the massive and smooth bottom end the 2013 gives

Just take it easy... Play safe... Good luck

Brand new Novarossi BTT-WC engine. The port in the slave doesn`t match accurate with the case.
Huge manufacturing tolerances?

I've seen a lot of internals like that. Most of the time, manufacturers will machine out a case that will fill several models. Thus the reason some of the ports in the case don't match exactly with the sleeves. Not a big deal IMO. The sleeve is what is metering your port flow, timing, transfer ect.... That is more important the making the case match the sleeve on every model. If NV did this, they would have to have like 50 different cases for each model they sell. and that's just their .21 line.

I know there are a lot more Motor Guru's on here that will chime in.

thats normal on any engine

Shudnt be a problem as long s p/s fit in

I have never seen such a huge tolerances in any engine i used before.
And the btt is the most expensive engine i have.

Here a pic from my RB Blast V4. Very nice fit. My p5XLT looks similar the RB.

Not a problem in any way , shape or form , run it

Is the Plus 4-BTT still a good option for a buggy?

Longevity question about nitros

When my Nova Keep Off 7 engine is cold with everything installed on it its still very hard to turn over all the way through a cycle. How much fuel will it take to kill away all that compression if ran at reasonble tunes and always at BDC after runs and always pre heated?

....oh ya and broken in correctly and not rushing a lean tune

Many factors like quality of fuel n air filter... Keep a good maintenance then it will last