cg125 engine change

[Guest]

here's the story:

i bought a 1994 cg125 off ebay that was a non runner for the princely sum of £100. the previous owner said it 'definately' ran last time he tried it.

managed to get it up and running with a few minutes of fettling and new fuel, but the bike wobbled from side to side!!

you guessed it, flywheel was loose and rotating in and out due to a smashed up woodruff key, shards of woodruff key and shaft flying around everywhere in the casing!!

anyway... i decided that instead of fixing the battered old 25k engine i'd change it for a 2004 engine i had in a cg125 bike i had a couple years ago (was crashed into and frame bent, but engine fine 'n' dandy) this engine ideally has electric start, and just 5k mileage.

the other day i took my old 1994 engine out and put the new one in (which fit in perfectly by the way for anyone who's ever wondered, the mounts are all exactly the same, and probably have been from the 80's until recently)

past few days have been spent putting the new loom through and doing the odd job... however, here are my questions:

mainly bothering me is the airbox. the 2004 airbox will not fit in the 1994 frame, even though i've removed as must as i dare from the plastic to make it fit.... 'but why not keep the old airbox then' i hear you ask... well, there's a problem with that.

the 2004 engine has a pipe running from the carb to the airbox, and another one running from a module which has another pipe from the rocker cover. (you can see it on the picture ive included which is not of my bike... the thing i'm on about is below the tank and i think it's an oil filter. the old airbox just has the big pipe to the carb, and a run-off pipe. so my question is, do i need these pipes from the bottom of the carb and the oil filter to run to the airbox? or could i just let them breath on their own.

thanks, if anybody can help it'd be much appreciated, and i'm sorry i couldnt be more clear about what im talking about.

also: does a crack in the headlight fail an MOT?

http://i24.photobucket.com/albums/c16/arron0909/Untitled-1.png

[Fozzie]

Im selling a 2005 engine and it has this...

http://www.team-bhp.com/forum/iipcache/83403.jpg

I chopped off the pipe and connected this up. The bike worked fine, no difference at all

If you want I can give you the link

[Guest]

cheers...

i managed to get the new airbox in the old frame. minor tweeking and some sealant but it looks ok, just gotta get it running before i can do anything else.

anybody know how to get an exhaust off? mine seems to have welded itself in via the sleeves!!

[Grumpy Old Git]

Penetrating Oil (WD40 will do) - Drip/spray lots every hour or so for a day - leave overnight - re-spray and leave for 10 minutes, tap with wooden/plastic mallett and it should start to free.

Alterntative (if you don't need the old exhaust pipe and sleeves / clamps): Cut off the pipe about 2 inches from the cylinder - cut longways internally (need a decent free-blade metal saw) and, once through, crush with a vice / mole grips and extract.

Warning: If you do this, remove cyliner head and barrell and througally clean out any swarf. Rebuild, flush oil through before filling crankcase.

Paitence is needed!

Good luck.