Puch Moped Head on HT 67cc bicycle engine- thanks Foureasy!

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foureasy

foureasy

New Member
Jul 9, 2009
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tucson
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!



I just moved the combustion chamber to the intake side of this gila head.

Also, threadjack!!!
 
furament

furament

New Member
May 31, 2009
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ontaro
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

i wrote that?? wow ya thats just wrong! my bad sorry!!
 
GearNut

GearNut

Active Member
Aug 19, 2009
5,104
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San Diego, Kaliforgnia
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

So long as the hole pattern is identical to your factory HT head, make the holes bigger in the puch head with a drill bit. It is best done using a drill press to ensure that the holes are held perfectly straight, but a steady hand and a careful eye can do it with a hand held drill as well.
 
Arnie

Arnie

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Dec 25, 2010
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Wrightstown,New Jersey
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

did the head make it any faster? I tired the 70cc puch head and I could not get a socket in the head to tighten the bolts.
 
adb140275

adb140275

New Member
Aug 8, 2010
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Harrison City, PA
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

yeah u gotta use nuts that use the 13mm socket or it wont work. thats standard for M8 nuts.

yeah it gained more rpm, lost torque because it lowered compression. smoothed it out a lot
 
Goat Herder

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
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N.M.
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

Prolly need a nice thin walled socket from Napa , Sears or just from a good Auto Parts store.. The cheap sockets will have thicker walls to them because the steel on them is not quite as good.
 
Goat Herder

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
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N.M.
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

OK did not know it is that narrow. Makes since now.
 
ToxicAz520

ToxicAz520

New Member
Mar 11, 2011
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Tucson,Arizona
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

Did Youn put the 50cc hi hi head on a 48cc or a 66cc? Or is is possible to mount the 50cc hi hi head on a 66cc or do I need the 70cc hi hi head cause I messed up and bought the 50cc head when I have a 66cc motor.
 
DaveC

DaveC

Member
Jul 14, 2010
969
1
18
Boise, ID
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

If I remember right I *think* you have a 13:1 compression ratio... 70cc head on a 66cc is supposed to be 11.5:1. If you do have a 50cc head on a 66cc you will need an NGK B9HS or equivalent to prevent ping.

One thing I did to help starting it up is to back the bike up against the compression. You can feel when it doesn't want to turn over from compression. Get up to speed and drop the clutch, the motor gets a running start at turning over. If the piston is where it wants to compress a lot of times it just won't turn over. Especially if you have a good ring seal, too
 
ToxicAz520

ToxicAz520

New Member
Mar 11, 2011
288
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Tucson,Arizona
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

thanks guys. I got it on but can't even turn it to start it with the shift kit. plus i checked the piston clearance and the piston is goinna hit it. I dnt wanna ruin the shift kit so i probably gonna sell it and get the 70cc. I may try doubling up the gaskets but I really got the head for the added cooling more then the compression.
 
Goat Herder

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
Re: Puch Moped Head on HT 67cc motor- thanks Foureasy!

On some of these Motors the port timing is a little low set on the jug itself. You may find benefit in shimming the jug up with a thicker gasket just a tad as well.
 
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