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Post by chettm on Jul 23, 2014 9:13:47 GMT -5
Hey everyone! Quick question, the exhaust bolts on my Roketa mc-23-150 broke off and I'm unable to get them out. I ordered a complete emissions gy6 cylinder head from parts for scooters ( www.partsforscooters.com/164-302-Complete-Emissions-GY6-Cylinder-Head). 2 questions; Is this able to be done without removing the whole engine? Do I need to do anything to the pistion that is already there or should the pistion also be replaced? As always thank you in advance for any help! |
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Post by spidergoat813 on Jul 23, 2014 9:38:30 GMT -5
You can replace the head without removing the engine easily. Make sure you have the cam set correctly so you can keep it all in time. You don't need to do anything with the piston if you're just replacing the head due to not being able to get some bolts extracted. Just replacing the head the piston should stay in the jug.
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Post by ramblinman on Jul 23, 2014 11:39:36 GMT -5
Make sure you have the cam set correctly so you can keep it all in time. yeah, double check the timing after you tighten the 4 nuts. |
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Post by rockynv on Jul 23, 2014 11:53:02 GMT -5
You need enough room to pull the head off over the studs. On my Lance Vintage there was a lower bracket for the seat tub in the way so you had to pull the engine. It all depends on the design of the frame on your particular Roketa
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Post by shalomdawg on Jul 23, 2014 12:19:13 GMT -5
howdy chettm and by the way welcome to the forum
lotsa miles and smiles to ya
ken
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Post by chettm on Jul 23, 2014 14:04:19 GMT -5
Thanks for the help and the welcome!! I had read to mark the chain with the cam shaft so when I put it back it will be right where it was. Does anyone know if that is correct for the timing? The guide I read also reminded me about the valve clearance. Thanks again in advance for all the help and advice.  |
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Post by alleyoop on Jul 23, 2014 19:53:13 GMT -5
You bet BRO, bring it up to top dead center as if you were going to adjust the valves and then mark the cam and chainlike this. Then once you get it all buttoned up then adjust your valves. Alleyoop  |
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Post by chettm on Jul 24, 2014 6:48:42 GMT -5
Thank you everyone for the help! I'll let everyone know how it goes. This will be my first real engine work since having it. More to follow!
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Post by rockynv on Jul 25, 2014 6:18:33 GMT -5
A word of caution: The two bolts on the side of head in the timing chain area do require some finesse as the metal in that area is a bit thin so if you crank them too tightly you will put a minute crack in the thin area of the casting that can eventually or sometimes immediately weep oil like the head had become porous. After that you will need another new head. A good job cleaning the mating surfaces, a finger smear of gasket sealant and a light touch snugging those bolts will help prevent it from cracking while still giving a good seal. The four studs that hold the head to the cylinder should be torqued to spec but on the light side of scale..
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Post by chettm on Jul 25, 2014 6:52:55 GMT -5
Thank you again for the help. I hopefully will get time and get this done on Sunday. You probably just saved me another $70.00.
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..BAD TO THE BONE..