Hi guys,
Been riding our minibike WAY too much! lol
SPent the last month fiddling with a Mikuni carb and finally had it dialed in. We have a fairly moderate built Predator engine on an Azusa minibike. Oil has been changed regularly. Current build is as follows for backgroun info
Predator 212
Arc Standard length rod with stock dished piston
Arc billeted flywheel
NR Racing 18cc head, milled 0.050, ported and polished with SS valves
26 lb springs, 1.3 ratio rockers on intake
Mod 2 Cam
Mikuni 22mm carb
Header (braced on block)
GTC TAV
Was riding today, hit probably 6500 rpms (usually no issue)....felt a surge and a "bang/Crack"...started throwing oil everywhere.
"Oh CRAP"...no power....manually shut it down immediately...walk home lol
My initial thought is that I threw a rod, as I could see a huge crack at top of engine (top of cylinder housing). I spent the next two hours stripping the engine and removing from frame. Interestingly enough, pretty much EVERYTHING is intact EXCEPT the block. The cylinder head literally broke off from the "crank case". Head is totally intact. I can post pictures if you think helpful. I had just checked oil prior to this ride.
A fractured block alone....is this a common failure? I realize this is a Chinese made block of variable quality. I ordered another block from EBAY.
In the mean time, I thought I would ask to see if there are any suggestion on avoiding a repeat of this?
Thanks
Been riding our minibike WAY too much! lol
SPent the last month fiddling with a Mikuni carb and finally had it dialed in. We have a fairly moderate built Predator engine on an Azusa minibike. Oil has been changed regularly. Current build is as follows for backgroun info
Predator 212
Arc Standard length rod with stock dished piston
Arc billeted flywheel
NR Racing 18cc head, milled 0.050, ported and polished with SS valves
26 lb springs, 1.3 ratio rockers on intake
Mod 2 Cam
Mikuni 22mm carb
Header (braced on block)
GTC TAV
Was riding today, hit probably 6500 rpms (usually no issue)....felt a surge and a "bang/Crack"...started throwing oil everywhere.
"Oh CRAP"...no power....manually shut it down immediately...walk home lol
My initial thought is that I threw a rod, as I could see a huge crack at top of engine (top of cylinder housing). I spent the next two hours stripping the engine and removing from frame. Interestingly enough, pretty much EVERYTHING is intact EXCEPT the block. The cylinder head literally broke off from the "crank case". Head is totally intact. I can post pictures if you think helpful. I had just checked oil prior to this ride.
A fractured block alone....is this a common failure? I realize this is a Chinese made block of variable quality. I ordered another block from EBAY.
In the mean time, I thought I would ask to see if there are any suggestion on avoiding a repeat of this?
Thanks
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