Remove cylinder head 1chinese motorbike GY 125

Thanks for the great uploads of this procedure, you have given me confidence now in doing this! :)

Hi, I really need a hand I'm getting a new. Replacement bore tommorow, any chance you can explain the timing and anything I should be aware of, many many thanks . Izzy.

Prob silly.questchong.butnwhat sparck.plug u recomend.for.this engin

@EverMellow Timing on these engines is fixed but crank and cam needs to be accurately meshed. I haven't fully stripped one of these engines so i can't give you any specifics, however, if it's the exact same engine as this, it's based on the Honda CG125, grab a haynes or similar manual and that will be able to step you through the strip and rebuild process.

I took the engine apart because it wouldnt go in to gear . And now that iv got it back together and the gears work . It won't start . I think it's out of time . How do I fin the timing chain . Or ajust the timing

@cyclopse50 If you're not confident then certainly get a mechanic or a knowledgeable friend to do it? I will say it's all very straightforward, when you write things down, especially if you're unfamiliar with mechanical things it can sound complicated and confusing but the process is really quite straightforward. I've done this job myself on the ZZR250 I had years ago, if the forums is still on the go i'd recommend you register at ninja250(dot)org, v helpful people on there.

@spidiq8 Errr... I dont know how to do any of that. And at the risk of possibly ruining my bike. Ill leave it to the mechanics. :( Who woulda thought something like this took so much effort

@cyclopse50 Just had a look, yep, thats the UK spec ZZR250, so tank off, and you'll see a coolant pipe and stat housing going across the top of the rocker, front to back. Drain the coolant, bottom rad hose off, good time to renew it, pro cool's good btw, take the pipe and stat housing off, HT leads off and unbolt the rocker and lift straight up, leave the plugs in to make sure no dislodged crud drops in. Check and set the valve clearances while you're in there too, screw and locknut so easy job.

@spidiq8 It has the frame like the bike in my video. I dont know what frame that is. The bike started to smell like it was burning oil. I took it to the mechanic and they changed the oil, filter, air filter, spark plugs and identified a slow weeping leak on one of the rocker covers. I dont know if it is the gasket around the spark plugs, or the actual cover gasket... the mechanics could be wrong though? I'm no mechanic so i wouldnt know anything....

@cyclopse50 If it's the UK spec aluminium bean framed ZZR 250 with the GPZ250 4 stroke twin engine then no but, you will need to drain the coolant and remove the coolant pipe and stat housing that runs across the top of the cylider head. The tank needs to be off to get through the top, with the ally frame, unlike the gpz US spec Ninja 250 cradle frame you don't have enough room to lift and move the rocker out of the side. Are you sure it's the rocker gasket leaking?

Do i need to remove the engine to get to the rocker cover? I need to just replace my rocker cover gasket. I have a ZZR250

hi i have a engine just the same i am trying to take the engine of the bike but cant get the bottom bolt of which is the last one and will not turn any solutions or have i took the wrong bolts out first

@alex15969 You could lift it out by hand quite easily, a jack would be handy to hold it while you unbolt everything, make sure the cables are all disconnected first then lower it and lift to your bench

@christiancoker1 Do you want to expand on that? so far it's a one word question with no clear definition of what you're asking

@spidiq8 Ok I'll give it a good service and check the speed, thanks again...

@rimfa123 If you follow my videos for the valve clearances and make sure you turn the engine by hand afterwards and recheck the clearances you can't go wrong. The rest is a breeze, just remenber it's an alloy engine so don't overtighten anything. One more thing to mention re speed, if you're running on the knobbly motocross tyres, this will create more drag and make a difference to cruising and top speeds, sounds crazy I know but it really does.

@spidiq8 Oh, and I just remembered, the guy that owned it before me fitted a new speedo cable himself, not sure if that made a diffrence? And, I only way about 10 stone or so, but I can see where you were coming from lol. I was also considering buying a windshield and fitting it as someone told me that this reduces the parachute effect and that might get a few more mph's. But yeah, I'll do what you suggested, hopefully your videos and a haynes manual should get me through it, thanks again...

@spidiq8 Thanks for the response... I think I'll go ahead and borrow a sat nav off a friend and check the accuracy of the speedo, as far as I'm aware, the bike has been reasonably cared for, but, despite alot of polishing on my part, it's not spot on, I can only assume that mechanically it's the same. I think it's time for me to buy a haynes manual and do what you suggested, at the moment, I'm not really confident doing much more than changing a spark plug, but I suppose this should change...

@rimfa123 than the speedos these things come with, you may find you're cruising at a reasonable speed anyway, often you'll find other vehicles habitually cruise a good 5 - 10mph faster than the posted limit making you seem slower. A service most certainly won't hurt anything, don't go fancy on the oil, a basic mineral or part synth, regular changes are more important, try an Iridium type plug and most important make sure the valve clearances are right, nothing will go right if they're out.

@rimfa123 It's tricky to say if theres anything wrong with it without looking but with these little bikes there are so many factors regarding performance. Hows it been treated in it's 9 years use?, has it been thrashed and poorly maintained? the size of the rider makes a difference, no insult intended but if you're a big fella that can kill a few MPH, it's worth getting a satnav unit and checking the actual top speed and cruising speeds you're getting, they are typically more accurate cont......

Remove cylinder head 1chinese motorbike GY 125

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