engine exploding?



With my 70cc engine and the 44th sprocket that comes with dax's kit, with full throtle can I go fast enough on flat ground that the engine would explode or something like that? If not, how far does it have to be pushed for it to explode?

Thejman said:
only thing I know that would explode these motors would be NOS.

That or running too lean.

NOS is nitrous oxide, a gas that oxigenates the fuel. You need to run a solenoid to allow more fuel to be admitted to the carb if you run NOS.

It's for race cars, not little bike engines, and not really good for two stroke engines of any kind. Less than scrupulous folks sell "NOS kits" on ebay.

Run away screaming!

You shouldn't be able to blow the engine by running it in the stock configuration with the factory supplied sprocket.

Make sure your intake gasket is in good condition as they tend to leak air after awhile. Leaking intake gaskets (among other things will make the engine run lean....
yea mine does the same too, it seriously screams! i thought i would blow it up too! not to mention that the seat vibrates like crazy! but i hear these 2 strokes like to run like that. i abuse mine like crazy and it hasn't given me any problems!
it can't hurt itself...as bikeguy sez, optimize the stock configuration and go for it :devilish:

(always be on the lookout for top-end 'surging'...a clear sign of an intake leak & lean conditions, not cool)
You may damage your engine if your go full throttle downhill. The cheap chinese metal connecting rod may not be able to handle overrevving while downhill. Should not be issue on straight away or up hill.
Bikeguy Joe said:
True, but you'd almost be asking for a meltdown if that were the case.

I'm not sorry, but I can't let your statement stand without questioning its basis. A meltdown? What in the world are you talking about?

The con rod is under tremendous stress from the reciprocating load represented by the piston, actually stretching and relaxing with every rotation, and the load increases rapidly with increasing engine speed. Failure of a connecting rod is one of the most common causes of catastrophic engine failure. It is often considered an engine's "weakest link".

So, could you repay the favor and explain what you mean by "meltdown". If you were emplying engine seizure, overrevving won't necessarily do that unless it overheats from being run too lean.

Sorry for any misunderstanding....

I'll put it another way.

I one were to run one of these admittedly old-tech engines downhill long enough and fast enough, running at redline or above without a perfect mixture, it would encounter some form of catastrophic failure. Otherwise know here in north east Ahia as a "meltdown". (although not the type experienced by many folks in Holly-weird)

Could be in the form of a snapped rod, bearing failure, ring or piston skirt breakage, seizure, ect. In other words, you turn your engine into a small pile of inexpensive scrap/tears/swearing/capital loss.

If one were to run one that hard, they should not be surprised or upset when the whole thing goes "kablooie" :eek: :( (tech term there). :D

I didn't mean the engine would literally "melt down" that would take a lean run of about 30 seconds at which point the aluminum would turn to clay (once again not literaly) and melt....I've seen it in many two stroke engines.