new skyhawk head cap?

[earl.k]

i was replacing head bolts today and noticed something was different. i have two shyhawk motors from 2010, but a few months apart. the older one has the same stock head cap as all the other china two stoke motors iv seen. but my new skyhawk has what im thinking is a more high comp head.. or there try at one.?

anyone notice this, or have the same head? or is mine just bunk? here is some pics..

old..

new.

if you can see the old one is just rounded out like a bowl.. and the new one has a smaller center bowl area, but also a slight step to where it all seals..

if you can see the rim around on the step down where it drops into the bowl like area. this was poorly cut, and hit the top of my piston leaving a deep half circle.lol i did hear some ticking in my motor that went away after some use.. guessing that was it.

any thoughts on any of this are welcome.

 

[earl.k]

here are two more pics from a top view..

old

new

 

[earl.k]

anyone know anything about this??

 

[CaliRebel]

The SuperRats are supposed to have higher compression that I assumed was from a different head. They may have added the new head before they marketed it with the new motor. I didn't pay attention to the shape of mine... Maybe I'll open up my SuperRat to check out the head.

 

[corgi1]

is the head gasket going bad on the newer one w/the squish band,looking at the top of the pic

 

[earl.k]

The SuperRats are supposed to have higher compression that I assumed was from a different head. They may have added the new head before they marketed it with the new motor. I didn't pay attention to the shape of mine... Maybe I'll open up my SuperRat to check out the head.

if you end up doing that pleas let me know what you find.

 

[earl.k]

is the head gasket going bad on the newer one w/the squish band,looking at the top of the pic

the head gasket was holding up fine.. the head bolts on the other hand are the biggest joke ever. i got a junk motor all around. my first skyhawk was made 1 month and 10 days before this on. i like my old one, and my new one is total junk.

the reason the head is leaking is because. every time i try to tighten the M6 head bolts down one brakes or the nut stripes out.. i even got the SBP replacement ones and snapped on of them.. i tighten them down in a cross pattern and all that. but if i tighten it down to where it will seal my head right, i break a bolt. if i tighten them to where they are just about to break i have a leak.

i replaced the motor yesterday because of all the other problems with it.. NEW SKYHAWKS ARE JUNK. i tried to order a mega motors kit and got a old skyhawk kit, so ill run it till it dies. then its on to another brand..

 

[CaliRebel]

I really thought my SuperRat would have the different shaped head, but it looks perfectly rounded.

 

[corgi1]

I wonder if the head w/the squish looking band (earl.K's)was a bad casting and just machined enough to fit,,,,If it's machined uneven on the cyl.verses the bolt holes it will break bolts as it causes them to seat at an angle,,,there is a max torque spec for the bolts ,someone here will know(10-12 ft lbs?,not very much at all,,,is the cyl level and have you checked on a glass sheet and sand paper for a warped head,,,there should be no burn mark trying to cross the sealing ring part

 

[earl.k]

I wonder if the head w/the squish looking band (earl.K's)was a bad casting and just machined enough to fit,,,,If it's machined uneven on the cyl.verses the bolt holes it will break bolts as it causes them to seat at an angle,,,there is a max torque spec for the bolts ,someone here will know(10-12 ft lbs?,not very much at all,,,is the cyl level and have you checked on a glass sheet and sand paper for a warped head,,,there should be no burn mark trying to cross the sealing ring part

it has to be a bad cut.. my piston was hitting my head cap. the cut on the piston and the fact that i could hear it hitting tell me that much. and that why im thinking my head bolts started acting up.

also, the head cap is warped. i did check it on class, and next to two other ones i tested it is by far the worst one. none are just right. but the one i ran for a long time and never had a issue. and the best one is on my new motor(older skyhawk)

 

[earl.k]

hear are some pics of what the poorly cut cap did to my piston..

you can see the cut where it hit.. there was a lip that was not cut all the was down on the cap. you can also see where it hit my spark plug.. new NGK Iridium BPR7HIX, junk. but i put the Iridium BPR6HIX in right after. because its still to cold here to use the other and i dont want to get a new one. it dident hit??

 

[Alson]

Ya I just got a new SkyHawk and the head is like yours and bumber about the M6 boults too, the intake is like the Super rats also. Hope I dont have any problems like you did. Oh ya what is the proper tourq for the M6 head boults

 

[GearNut]

http://motorbicycling.com/f3/49cc-head-gasket-torque-30425.html#post290757

Al.Fisherman list the torque for both cylinder stud sizes.
Don't be fooled by the stated engine displacement in the thread.