cylinder head rework

[tigertamer]

I hate Easy-outs too! But I use them when needed.

I have snapped them before when I wasn't careful.

I must be very lucky to not have them snap every time :twisted:

Thanks,
Tigertamer

[elroyjetsn]

I've worked on several Subaru engines and the exhaust studs break on a regular basis. At least with a Chinabike replacement heads are relatively cheap. Under $100 say.

[chrism1]

Now that I am ready to reinstall head,does anyone now what the bolts should torque to?I should have checked them before i pulled it apart :roll:

[elroyjetsn]

Originally Posted by chrism1

Now that I am ready to reinstall head,does anyone now what the bolts should torque to?I should have checked them before i pulled it apart :roll:

23 lb.ft.

[knothead]

Originally Posted by elroyjetsn

23 lb.ft.

That seems terribly low for head bolts. But I don't even know what size the bolts are.

Here's a link to torque by bolt size;
http://dodgeram.org/tech/specs/bolts/M_bolts.html

Should get you close.

[elroyjetsn]

That's according to the Hayes shop manual for the Honda CG125 which is the pushrod engine that the Chinese cloned into the 125/150/200/250. So you may want to ramp up the torque a bit according to your bike's displacement.

http://www.chinariders.net/gallery2/...2_itemId=10035

http://www.chinariders.net/gallery2/...2_itemId=10041

[knothead]

Originally Posted by elroyjetsn

That's according to the Hayes shop manual for the Honda CG125 which is the pushrod engine that the Chinese cloned into the 125/150/200/250. So you may want to ramp up the torque a bit according to your bike's displacement.

http://www.chinariders.net/gallery2/...2_itemId=10035

http://www.chinariders.net/gallery2/...2_itemId=10041

I don't trust Hayes manuals. The one for my Jeep said to torque the front axle nut to 120 ft/lbs... the problem with that is it would mean torquing the tapered bearing in the hub down that tight... BIG no-no as the nut should be tightened to around 14 ft/lbs, backed off and then tightened finger tight. The same manual called for 65 ft/lbs on the Jeep's flywheel bolts... in reality they torque to over 250 ft/lbs (175 ft/lbs + 60 degrees more). I've found other mistakes in several other Hayes manuals as well. If something doesn't sound right, it probably isn't.

It seems to be that 35 or 40 ft/lbs would be closer to the truth, depending on the size of the bolt and pitch of the threads.

Just sayin'....

[Forklift352]

I know a guy that wants to check out the insides of my 163 FML.
I think its the push rod clone.Anywho....He says a higher compression
piston, intake port job,more aggressive cam,and carb should yield
25+hp 8) He says if he could get measurements he could get a piston.
Has any body tried this????If not maybe someone could measure :P

[knothead]

Originally Posted by Forklift352

I know a guy that wants to check out the insides of my 163 FML.
I think its the push rod clone.Anywho....He says a higher compression
piston, intake port job,more aggressive cam,and carb should yield
25+hp 8) He says if he could get measurements he could get a piston.
Has any body tried this????If not maybe someone could measure :P

I have said for a long time that the way to get more power from these engines lies in bumping up the compression and helping them breath. 22~25 hp isn't too far fetched. (as long as the chamber shape will allow higher compression). The life of the engine/transmission......???
Easier/cheaper just to buy a used XR 250 since they have that much hp stock and a much better suspension to boot.

[TeamCheap]

Originally Posted by knothead

Easier/cheaper just to buy a used XR 250 since they have that much hp stock and a much better suspension to boot.

That is sacrilege is these here forums but true. :wink:

[kevj46774]

I have found in the past that the easiest way to remove a snapped bolt or stud is to weld an nut to the end if there is enough material left to do so.

[elroyjetsn]

Originally Posted by TeamCheap

That is sacrilege is these here forums but true. :wink:

+1

cranking 20 or more HP into these little 125 gearboxes designed for 11hp is askin for trouble...