what bike is this?

[locko90]

hey guys I bought this 250 china bike at the wreckers today for 50 bucks, would anyone know what type it is ??

also is it fixable?? or have I wasted 50

engine is seized but maybe I could open it up and and fix it ?

looks to me like its been sitting for ages and maybe with a bit of tlc could get it up and running.

let me know what you think

 

[my67xr]

It look's a lot like the Crossfire 250 bikes- Crossfire CF250 250cc Dirt Bike 19" 16" Similar Size TO CRF125 150 | eBay
Part's would still be available

 

[locko90]

It does look alot like the cf250. Cool think I could fix this bike up ?
What engine does it have ?

Tomorrow I'd like to take the engine off and see if I can take it apart

 

[my67xr]

Is there a model number on the engine somewhere ?
Something like 162 FMJ, Loncin and Zongshen make them, probably a few others too
Zongshen 250 (230cc) 250cc Zongshen OHC AIR Cooled Engine Motor Bike Motorbike Motorcycle Chinese | eBay
Zongshen 250cc Engine Motor Manual Clutch PIT Trail Dirt Bike 1 Down 4 UP | eBay

 

[Chops]

Looks similar to a ducar that a friend had?

 

[locko90]

been watching some guides on youtube on how to take this engine apart, looks like theres alot more involved then what I was thinking hahah.
would u know what tools id need to tear the engine down and what problems I should be looking for to get it running my67xr??

chops: im kinda thinking its the crossfire man the frame looks so similar, its kinda funny actually about 2 weeks ago I bought a crossfire cf125, and now not knowing I got the cf250 hahaah weird.

 

[my67xr]

The bike you bought is one of the original 250's, who know's who made it.
Crossfire must have done a deal with the same company in china that made the frame to use on their bikes.

I would be taking the head off first and seeing if you can free up the piston.
Pour a little kerosene into the bore and let it sit over night at least, then try turning it over the next day
If it doesn't turn over add a little more kero and wait another couple of days

 

[locko90]

yeah well on the frame model plat it has 2006, so shes a bit of an old bike.
engine looks very similar to the zongshen 250.

how do I take the head off? is it just the 4 bots on the top ?

a mate of mine I was just talking seemed to think that for the seized engine I should drop the oil and put diesel in and leave for a week ? is that worth doing or no ?

 

[my67xr]

For the head to come off, first you need to take the cam gear cover off and remove the gear from the cam shaft.
Then the 4 head bolts, there is another bolt that hold's it to the cylinder too
Might pay to find a service manual for it, pretty much the same engine as an early air cooled Honda CB250 engine


Yeah either diesel or kero, they're much the same.
Pull the spark plug out and pour some in, let it sit.
Take the stator cover off and try turning the flywheel once it's sat for a while

 

[locko90]

k ill put a bit of diesel down the spark plug hole today. is it a good idea to fill the engine oil compartment with diesel as well? I was thinking it might clean it out a bit?

been watching a few vids on taking the cylinder head off and sort of getting an understanding of what to do, some parts look a bit tricky.

like how do I mark the cam gear to keep the timing chain in correct position, does the cam have to be marked to go back in the same position aswell?

but anyway ill just do the diesel today and see if I have any luck with freeing the engine up, fingers crossed :hail:

 

[locko90]

oh and I got a engine manual off the crossfire website, and the air cooled Honda cb250 engine manual.

both don't really go into depth about removing the head.

would anyone know of some step by step maintenance guides on these engines ?

 

[locko90]

So I put about 100 ml of diesel down the spark plug hole. Was going to drop oil but there was no oil screw on bottom of motor just one on the side not sure if that's the sump screw but didn't have a s****ett to undo it anyway.
So hopefully that frees it up

 

[emmo1980]

dont pull the engine apart just let the diesel sit in there and try turning the flywheel {take the spark plug out first you dont need to be fighting compression as well} if the engine turns then turn it both ways put a little 2 stroke oil in the bore, if you have a rattle gun or a powerfull drill get that onto it and spin it like mad.

check the rear tyre for a big flat spot that would indicate the engine might have locked up while being ridden, chances are that its only locked from sitting and will come good easily without being pulled apart.

while you have the engine soaking pull the carby apart and clean it everywhere preferably with compressed air and carby cleaner if you can

good luck.

 

[locko90]

cheers man yeah just letting the diesel sit in there atm, I put about 100ml -150ml down the spark plug hole today. after sitting for one day its not turning over, going to let it sit for longer and if still no luck im going to take the engine out of frame and remove the head and see if I can get the piston freed up.

bike does look like its been in the weather for years though, there is a lot of work to be done on this bike, not sure if its worth it, thinking maybe if I can get the engine running then yeah sorta.

but on the bright side its only 50 bucks and Im learning how to fix motorbike engines