can any 1 help iv noticed a small crack in the outlet on my engine where the exhust fits on its a nac 28 hobao every thing seems ok all bits mooving freely and restriction in all right places will this be a problem can any1 reply asap ps havent used engine yet turned it over once on idle al seemed fine this a new car and im new to this game i see this thread gets read but no1 answers could som1 give me their thoughts on this matter as im worried its a major prob this is my noob showing thanks

If it is a new engine there should be no cracks. Even if it does not effect performance I would still contact the retailer that you purchased it from. They should replace the engine for you.

ah its new but when turned over for first it revved like mad full throttle i have had idleing for a full tank do u think the high revving has made this crack?

I doubt it. If it ever goes wild rip off airfilter and plug intake.

You can just pinch fuel line just above HSN input. Ripping of the filter while the engine is at full throttle could cause something to get sucked into the carb. That would really suck.

That crack has permanently damaged the structural integrity of the engine. I see a waranty in your future.

how did crack get in there? it should be like in a can or pipe right?

he had a runaway because he set his servo up wrong.
His servo was not reversed, so it was running opposite.
Idle was 1/2 throttle and throttle was brake, brake was full throttle
so, he started it and it instantly revved to full throttle(new engine)
probably created a crack since the sleeve is way too tapered when it's new and it expanded all the other parts way too fast, cracking

The guy has a serious problem with his engine and I'm not trying to be funny here, but how did you figure that his problem was caused by your hypothesis? It's almost as if you were there in the UK with him when he started his engine. Seriously, if you're that good I will be PM'ing you on some questions of my own.

I highly doubt that him over-revving his new engine would've caused a crack in the exhaust port. It's definitely a manufacture defect I'd say.

i've seen motors stick wide-open as soon as they came out of the box, but that was a faulty fail-safe that caused it (and dead receiver batteries), but it wound wide-open for 15-20 seconds and there weren't ANY cracks...i'd say it was cracked from the factory or it was a problem with the metal

over revving for too long could only breaks the conrod, which eventually breaks the cylinder and engine body at the same time by the broken conrod. Remember that "DOG" sound and the engine suddenly stops? If you have never dropped your engine, this should be the manufacturing defect.

Also, the most efficient way to cut a wild revving (lost control) engine is to stop at the exhuast pipe. Grap the chassis, press it against the ground to decrease rev, then use your shoes to cover the exhaust pipe hole. If you have good gloves or a towel, you can use your fingers.

sound thanks for help i sent engine back to shop and they said it was a manufactering line wen they make the engine its on both sides aparently