Zongshen ZS12532 Engine Seized HELP

[jaymcfr]

Bought the bike on friday and it had only done 106 miles and it had been sitting redundant for the last 18 months. Older owner and she lost interest basically. Drove about 200 miles the last 48 hours and was breaking it in gently. However started having problems with the electrics. Think the battery needs replaced and made plans to do this tomorrow. Tonight driving home it wouldnt let me have ma lights on and indicate at the same time. No indicator flash would just screech but when I turned lights off it would work fine. Thought it was the battery so thought oh well will fix tomoz. Driving home at around 45 mph and the bike cut dead and the back wheel locked. Bike slipped to the left and luckily not the right otherwise I would have been ran over from the 3 cars that went past. So i managed to steer into the way the bike was slipping and pulled up with no engine power. Kick start pedal locked which indicates the engine has sezied. bikes fecked now and wont start obviously. Anyone had this problems. Whats the cost. What needs done etc. Gutted. Spent my whole wage on the bike :(

Any help or advice please!

[mizke]

if you are in canada giobikes.com sells a 250cc 4 stroke motor for around 600, doing the swap would not be to hard just have to make sure that the front and rear sprockets line up with each other and then work out the wiring on the new motor

[FastDoc]

I think you only have to be a Canuk to buy the bikes, but anyone can buy parts from Gio.

[mizke]

parts yes any one can buy, but when it comes to full bikes or quads and motors you have to be in canada.. gio will nto ship a bike or quad to the states.. but they will make the attempt to ship a motor.. altho most times the motor gets stopped at the border and sent back to gio

[jaymcfr]

Ok Wee update. apparently the engine splits into 3 parts. My bottom 2 parts are ok. Its the top where theres damage. This is getting stripped (head taken off) next week to see the damage. Something about piston rings and if they have scracthed something. any advice?

[TurboT]

Originally Posted by jaymcfr

Ok Wee update. apparently the engine splits into 3 parts. My bottom 2 parts are ok. Its the top where theres damage. This is getting stripped (head taken off) next week to see the damage. Something about piston rings and if they have scracthed something. any advice?

Hard to give advice here without seeing photos or having parts in your hand.

You'll just have to wait to see what the cylinder bore looks like when it comes off.

If it won't turn at all, I find it hard to believe it's the rings... but it is possible. I wonder if you swallowed something, somehow.

Keep us updated.

[jaymcfr]

soz a shuda mentioned tht. He hs unseized it and the camshaft or whatever its called is ok and gears are ok. He says only the top part can now be damaged. Is it logical that if i was quoted £600 for full engine that if its only 1 out of 3 that its gong to be like £200 - £3oo for the top part. Engine is turning but no compression!


cheers

[mizke]

if the engine is turning but there is no compression its the piston rings.. so it needs a rebuild, good thing is this. you can have it bored out to a larger piston and make some more power..

if you need a new top end, find the name brand big 4 that will fit it and let me know. i found a place while looking for a new yamaha warrior 350 top end for under 200 brand new, put together just needed to be bolted down to the block..

[jaymcfr]

So am I being naive in thinking the piston rings are like 20 quid and so is the piston so like £40 before labour. Or could there be other things in the top part of engine which could have been damaged as well?

Thanks for this!

[jaymcfr]

also when u say a rebuild do u just mean the pistons or the whole engine or whole of the top part?

Sorry lol

[mizke]

well its like this

you have to pull the piston to replace the rings, so since the motor is being torn into, then for good measure and peace of mind. its best to have a complete tear down and rebuild. then when its all done and over it with, do a proper break in and you have your self a brand new motor and no need to worry about something going bad in it for awhile aslong as you change the oil and what not..

piston rings
piston
seals
bearings
gaskets

i had a buddy who a had a honda crf 250, the time came for new rings. he replaced the rings, but didnt bother doing new bearings and seals, only replaced the ones that need to be removed for the new piston rings.. 3 months later a crank bearing went out, could have been avoided if he had spent the extra money to get the seals and bearings to replace them with..

[jaymcfr]

Ok I will recommend that to the garage although they should be doing that neway. So is the gasket expensive? Whats a guestimate all in?


Cheers

[mizke]

not sure to be honest have not had to do a rebuild on a atv or dirtbike motor..

i would say parts and labor on a full motor rebuild 500 - 800 somewhere in there.. but that is a guess so dont quote me on the pricing..

[katoranger]

I don't really know if a full rebuild is necessary since it only has a few hundred miles.


Spud just did a top end on his 30K mile zong. The bottom end was fine.


A top end requires new rings, maybe a piston, cylinder hone or bore, and a base gasket and head gasket. Plus maybe a few smaller orings etc.


Sounds to me like the bike probably had a defective part.


Allen

[Cal25]

You have to find out whats wrong before it can be fixed. No compression could be other tings besides rings. hole in the piston could cause it. So could a broken, bent , or stuck valve. Anytime a component breaks, there is a chance that damage will occur to nearby parts as well.