popping noise out of front end of engine....

[Legwon]

will be continuing with this later this week(i hope) once my new top end arrives.
i didnt get around to lapping the head that weekend, and i most likely should have. top end blew up, and jammed the bottom end :s .. on tues last week. vendor is supplying new parts.
the FIRST thing i will be doin is lapping the head & cylinder.
also getting a new clutch assembly and gear tool for my older motor, so i will be disassembing the bottom end of this one, to remove the debris and check for damaged parts.
any suggestions as to what i should be looking for when i do?

Long story short...
i ordered a clutch tool, received it, and stripped it the same night :s
was lookin thru my toolbox today for some bolts for my daughters bike( cleaning up for summer) and found a weird looking bottom bracket tool...
i thought.. NO WAY! have i had one the entire time and not realized it??
lmao!!! appearently i got a clutch tool with the original engine.

so anywho, i tore down the remainder of this engine to check for damages.
doesnt seem to be anything obvious thats wrong. lots of debris from the top end. cleaned it out. popped the bearings out.
and found another problem, blown seal
so now i need to get seals on top of most likely, bearings.

speaking of bearings. the NS 6202 were marked '6202/P6' and 'C&U'
the RS 6202 were marked '6202RS', 'CSI", and 'SHENLI'
are they stock or replaced?

 

[Danny Torino]

so i just finished up with the break in period, decided to take it for a good haul.
checked everything b4 i left.
it made it to the final destination just fine(with the exception of the kickstand rattling loose)
when i went to leave about 4 hrs later, i had this weird popping noise coming out of the front end of the engine. sounds like a balloon popping. pretty much every time it sparked.

i did make it home with out too much hassle. but it died about half way and wouldn't fire:s ...
had to walk up the bridge. and decided to try again on the way down the bridge(large bridge over a river).... took a bit but did fire up.. again with the popping.
had to keep revving the engine to keep it running at idle, and once i let it settle for a coast the engine revved down and just quite.

Ive checked the plug cable, its solid.
i pulled the head and found that the upper gasket was cracked. replaced that.
checked that all the casing bolts were tight.
and checked the plug, and spark while i was at it.

when for a test ride and had to get up to about 15km/h to start it...
again with the popping noise. its not a compression popping... as i said above, its like a balloon popping.

anyone have any ideas??

Yeah buddy, most likely the exhaust manifold gasket blew out some. Mine did this after one month. I pulled mine off, the gasket was crushed. This was due to me not installing it properly. It kept loosening and leaking and re-tightening too much. So to get by till I get a new high qual gasket, I used 5 layers of cardboard about .040" thick each. I traced the flange and cut out the holes and clear tapped them all together as one. Then I took a flat and a round file to smooth out the inside edges as uniform as I could. This is one thick heavy gasket! I used the 2 existing nuts, with 2 new lock washers with 4 flat washers for extra clamping. After that I used 2 ny-lock nuts with 2 flat washers in between the other nuts. I always used that muffler brace since jump also. Alot of riders break the exhaust studs off the motor from not using the brace. It sealed up bout 98%, I'll ride more tomorrow and might tighten down a lill bit to settle in. Good Luck.