Puch head on a 66cc HT bicycle engine with 6mm studs
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Re: Puch head on a 66cc HT with 6mm studs
Yes I used drill press and wd40 . Used hole size of old head an drilled them . Dan
Yes I used drill press and wd40 . Used hole size of old head an drilled them . Dan
Re: Puch head on a 66cc HT with 6mm studs
How doe's the head line up with the cylinder? nothing is offset leaning off to one side ?
How doe's the head line up with the cylinder? nothing is offset leaning off to one side ?
Re: Puch head on a 66cc HT with 6mm studs
We just made the clutch pads today , just road it a mile . We have a ride Sunday . Well tell you how they it work . Dan
We just made the clutch pads today , just road it a mile . We have a ride Sunday . Well tell you how they it work . Dan
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Re: Puch head on a 66cc HT with 6mm studs
Well have a Happy Fathers Day!, a ride would be real nice!!
Well have a Happy Fathers Day!, a ride would be real nice!!
Re: Puch head on a 66cc HT with 6mm studs
I like your garage. It looks strangely familiar.
Re: Puch head on a 66cc HT with 6mm studs
It's not my garage . There about four of use working out here . The guy that owns it started all this madness . We all have fun like a club house . There all ways 2 or 3 projects going on . I think we're the Burbank misfits . lol Dan
It's not my garage . There about four of use working out here . The guy that owns it started all this madness . We all have fun like a club house . There all ways 2 or 3 projects going on . I think we're the Burbank misfits . lol Dan
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Re: Puch head on a 66cc HT with 6mm studs
I had the same problem with mine till i put a ton of IPONE oil in it to go get gas, It was appox mix at 10:1 and the pinging went away and the engine really screamed then, till i put gas in it and the pingging came back.I finally got my NGK BR9HIX spark plug in, which was the last piece I was waiting for to install the new head. I was shocked that I could not find one locally, so I ordered 2.
With the BGF RB80 motor, which I am pretty sure is the same as the Grubee GT5a with 6mm studs, the Puch 70cc hi hi head fits perfectly, I did not need to modify it at all.
I test fit the head without any head gaskets, just to make sure that it would go on, and I verified that the piston will hit the head without the gaskets. I had ordered two new head gaskets for the 6mm 66cc motor from SBP and already coated them in spray copper gasket maker, so I slipped on the gaskets, put on the head, then tightened up the head nuts in a Z pattern.
Unfortunately the only torque wrench I could find that goes down to inch pounds uses the smaller drive, what is it, 1/4"? And my 10mm socket that fits is was too short, so I had to tighten them by feel using my longer 10mm socket on my "regular" socket wrench. So this evening I need to go out and see if I can either find an extension to fit the socket, or preferably a deep socket.
Oh yeah, and I switched to 93 octane a few days ago in preparation for the new head.
Riding impressions: love it! I was afraid my clutch was going to slip, but she fired right up. Noticeably more torque down low and mid range and the engine noise seems a tad less raspy. Usually if I let the clutch out around 10 MPH (this is with a 36 tooth sprocket), I still have to pedal quite a bit to get my 195 lb self going. With the new head, from 10+ she pulls on her own
I really am not sure about the high end since I think my CDI is unhappy. With the stock head I would start getting what sounds like pinging in a series of machine-gun style spurts starting around 33 MPH, which would kill the power. I could get her up to 37 MPH, but she tops out around there, which feels limited by the pinging. I was hoping going to 93 octane would help, but nope. I get the same behavior with the Puch head, except I get there faster
My Jaguar CDI should be here next week, so we will see if the CDI really was the culprit...
Re: Puch head on a 66cc HT with 6mm studs
That sounds like what you had too, since when you went to 10:1 you leaned the mix out until you added more gas.
Turns out what I was hearing was really 4 stroking from running rich, which I got rid of by going down to a 68 jet.
That sounds like what you had too, since when you went to 10:1 you leaned the mix out until you added more gas.
Re: Puch head on a 66cc HT with 6mm studs
Since there is usually a great difficulty getting a torque wrench socket in between the cooling fins on a Puch head has anyone considered using allen bolts like the replacement kit sold at PirateCycle ? seems to me that would be a lot easier! then get an allen wrench and cut it to fit in a torque wrench socket to get the proper amount of torque that is required.
Give me some feed back guy's
Since there is usually a great difficulty getting a torque wrench socket in between the cooling fins on a Puch head has anyone considered using allen bolts like the replacement kit sold at PirateCycle ? seems to me that would be a lot easier! then get an allen wrench and cut it to fit in a torque wrench socket to get the proper amount of torque that is required.
Give me some feed back guy's
Re: Puch head on a 66cc HT with 6mm studs
Peace, James
Just finished installing my Puch head as well, with just one head gasket. Enjoying a nice bump in power all across the RPM range. What I ended up doing, in addition to of course going to 13mm nuts, was I took an old spare cheap 13mm socket. And just belt sanded the outside of the socket, untill it would smoothly drop all the way down on the nuts. Problem solved....
Peace, James
Re: Puch head on a 66cc HT with 6mm studs
Grats on getting the head installed! The extra power is nice and I can only assume it cools better...
Re: Puch head on a 66cc HT with 6mm studs
^^^ Thanks! Oh yes it's a world of difference between the two. It seems to cool down faster between runs as well. With such a daylight and dark difference to the stock head, the first thing I'm going to do from now on is throw the stock head in the recycling bin!
Re: Puch head on a 66cc HT with 6mm studs
I am glade everyone is happy. It such a simple mod that makes a difference and looks good on the motor.
I am glade everyone is happy. It such a simple mod that makes a difference and looks good on the motor.
Re: Puch head on a 66cc HT with 6mm studs
What you give up, though, is the ability to torque down the head nuts as much (so far mine have not been leaking at 72 inch lbs) and you have wider spaced studs on your intake, and not all people making aftermarket intake manifolds will fit.
I would not make the hole spacing on the Puch head the deciding factor on your purchase, since it would be very simple to take your stock head and the Puch head to a machine shop and have them make them match if you did not want to do it yourself.
It did on mine, I have a BGF RB80. The Grubee GT5A should be a direct bolt-on as well.
What you give up, though, is the ability to torque down the head nuts as much (so far mine have not been leaking at 72 inch lbs) and you have wider spaced studs on your intake, and not all people making aftermarket intake manifolds will fit.
I would not make the hole spacing on the Puch head the deciding factor on your purchase, since it would be very simple to take your stock head and the Puch head to a machine shop and have them make them match if you did not want to do it yourself.
Re: Puch head on a 66cc HT with 6mm studs
Just a thought about the hard to reach nuts on the Puch head...
Coupling nuts. They're just long nuts. Perhaps long enough to grasp with a socket.
Just a thought about the hard to reach nuts on the Puch head...
Coupling nuts. They're just long nuts. Perhaps long enough to grasp with a socket.
Re: Puch head on a 66cc HT with 6mm studs
They'd have to be longer than the coupler nuts I've found. The fins are deeper than the nuts are long. They might be thin enough at the top where a socket would fit. I can't check, sold the head and motor it was on.
They'd have to be longer than the coupler nuts I've found. The fins are deeper than the nuts are long. They might be thin enough at the top where a socket would fit. I can't check, sold the head and motor it was on.
Re: Puch head on a 66cc HT with 6mm studs
You can use coupling nuts with a short socket head cap screw on top to tighten with long shaft allen wrench. They will require a tack weld so you can get them off. Make sure they are short enough not to interfere with head bolts. You can also tighten and loosen them with a 8 mm bolt, double nutted with one nut being a coupler. The screws welded to the nuts is handier. Do not attempt to epoxy them, been there done that, terrible idea. It was such a terrible idea it's how i got to the the double nutted bolt.
You can use coupling nuts with a short socket head cap screw on top to tighten with long shaft allen wrench. They will require a tack weld so you can get them off. Make sure they are short enough not to interfere with head bolts. You can also tighten and loosen them with a 8 mm bolt, double nutted with one nut being a coupler. The screws welded to the nuts is handier. Do not attempt to epoxy them, been there done that, terrible idea. It was such a terrible idea it's how i got to the the double nutted bolt.
Re: Puch head on a 66cc HT with 6mm studs
I use 6mm head bolts from Yamaha RD 125 air-cooled engines, they are long enough, and looks a little "racy" out of the engine. They are in actual intended as a guide between the cylinder head and cylinder, then use a short pin bolt. You can also use the original nut from old fan-cooled puch engines
I use 6mm head bolts from Yamaha RD 125 air-cooled engines, they are long enough, and looks a little "racy" out of the engine. They are in actual intended as a guide between the cylinder head and cylinder, then use a short pin bolt. You can also use the original nut from old fan-cooled puch engines
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