Ah the joys of an engine rebuild... any thoughts on why the head off this 175 is so pitted and what could/should be done about it?
(http://members.iinet.net.au/~allantud/pics/175%20Head.jpg)
VMX1963
Western Australia
VMX KTM (http://members.iinet.net.au/~allantud/)
AKA grenaded motor, somewhere in its life maybe a part of a piston skirt or rings got into the top end, how are your cylinder walls and bottom end?
Everything else is fine, but not knowing the history I'd say there's a good chance its had something nasty happen in the past.
Can anything be done about it? Is there any risk attached to continuing to use the head in that condition? There are no cracks to suggest the integrity of the cast is suspect.
VMX1963
Western Australia
VMX KTM (http://members.iinet.net.au/~allantud/)
Check your lower cylinder skirts for cracks & your oil ports for blockage--also check between the main brgs and crank seals-debris will be spun through the ball brgs. Do a leakdown test on the cases-a good hit with a ring will occasionally crack the cases . Depending on how the bike is used and how deep the craters are, the head can be reamed (you lose some compression) or the high spots can be ground off. Any high areas will become hot spots leading to pre-ignition. Take extra precautions at areas that may contact the head gasket,to prevent blow-by
rob
vmx1963,
First thanks for your act of Kindness on the Penton gas tank. Moving on to the head. There is no problem running the head as is. The only argument some true gearheads might pose is with the indentions that carbon could build up and cause hot spots. If you are going to lose sleep over this possibility you can do either of the following:
1. Take up stamp collecting. Or...
2. Carefully bead blast the area affected and not the dome area. One other thing it is best to tape off the head gasket area.
In closing just run good Oil(2-Stroke) and a touch of octane booster and you will be fine.
Hope this helps.
Ron Carbaugh
Quotequote:Originally posted by vmx1963
Ah the joys of an engine rebuild... any thoughts on why the head off this 175 is so pitted and what could/should be done about it?
(http://members.iinet.net.au/~allantud/pics/175%20Head.jpg)
VMX1963
Western Australia
VMX KTM (http://members.iinet.net.au/~allantud/)
Use emerie sandpaper around your finger and smooten all high spots out as mutch as possible.It will work.From what bike is the head???
Speedy---->>>>>>>
Helmut Clasen KTM
162 Hillcrest Ave
L9H 4Y3
Dundas Ontario Canada
Ph.905-627-5349
[email protected]http://speedy_c.tripod.com
Sachs GP-GS 250-7A reeds
Zuendapp 125 GS ISDT repl.73
KTM 450 EXC Auto.03
Duke spec.Edit,1996
Adventurer 02
Thanks guys, you've set my mind at ease and I'll follow your advice about smoothing out the rough spots as much as possible. Speedy, the head's off a Jackpiner that's being slowly brought back to life...
http://members.iinet.net.au/~allantud/docs/72Jackpiner.html
VMX1963
Western Australia
VMX KTM (http://members.iinet.net.au/~allantud/)
Looks like somone never cleaned the air filter or detonation. Pre ignition causes a lot of metal fatigue in the top ends. Hope its still useable, goodluck
VMX,
It looks like a broken ring did the damage. You can use a small ball peen hammer to lightly tap down the high spots and then use the sand paper like Speedy said. Make sure that none of the broken parts (Ring bits) are still imbedded in the head . If they were to come loose later it would be sad.
John D.
Quotequote:Originally posted by JOHN DURRILL
VMX,
It looks like a broken ring did the damage. You can use a small ball peen hammer to lightly tap down the high spots and then use the sand paper like Speedy said. Make sure that none of the broken parts (Ring bits) are still imbedded in the head . If they were to come loose later it would be sad.
John D.
JD,.( John Deere ??) You are sooo right.It was a ringdeding,..
dancing up and down,..Speedy----->>>>>>.
Helmut Clasen KTM
162 Hillcrest Ave
L9H 4Y3
Dundas Ontario Canada
Ph.905-627-5349
[email protected]http://speedy_c.tripod.com
Sachs GP-GS 250-7A reeds
Zuendapp 125 GS ISDT repl.73
KTM 450 EXC Auto.03
Duke spec.Edit,1996
Adventurer 02