Budget build with all new components

Larry Trotter

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Nov 26, 2017
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I am dong a test build with budget parts in order to learn a little before dong another when I am in Arizona. I have these parts: Walmart 26" Men's Roadmaster Granite Peak Men's Bike $68.00 delivered including tax and an ebay china girl kit $79.89 delivered https://www.ebay.com/itm/Bicycle-2-...m4400389fa3:m:m_sBWs-YbL0YD_vuFf-1Y0A&vxp=mtr . Also picked up a double pull brake lever for $12.00. So it looks like a functional bike for $160.00 I think? If this works here (Washington state) I will just sell it and duplicate the build when I get down to my place in Arizona in a month. All my pieces should arrive on Jan 4th. I will post some pictures and the results. Any suggestions would be appreciated. I do know this is sort of a science experiment with really cheap parts, but I don't need anything that will last for 10,000 miles either. Larry
 

crassius

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Sep 30, 2012
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seems OK, I've heard that granite can be a tight fit for motor & 50cc can be hard to get up hills, but it should be doable without too much effort
 

Larry Trotter

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Nov 26, 2017
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I already have the motor for the Arizona build and it is a China Girl 66CC. This is a test build so I can make up any needed adapters, shims or special tools before I go. I have a lathe, milling machine, drill press and wire welder here and nothing in Arizona except hand tools.
 

Larry Trotter

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Nov 26, 2017
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My 50cc engine kit arrived today. It looks nice and all the parts are there. Does anyone know if the external dimensions are the same as the 66cc version? And mine came with a clutch removal tool which I don't believe the 66 cc kit did. I will have the Bike on the 3rd so will start taking pictures then. Does seem this one has the 6mm head studs while the 66cc has 8mm studs. Larry
 

Greg58

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May 1, 2011
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As far as engine placement in the frame they are the same, I have one of each size currently and prefer to ride the 48 cc, its much smoother and more fun to ride.
 

Greg58

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May 1, 2011
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In the add it shows a angle plug head, is that what you have? My 48 is a 2011 straight plug head that I milled .40 off of to raise compression, still running as it came other than notching the skirt for intake port clearance.
 

Larry Trotter

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Nov 26, 2017
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Yes the 50cc and the 66cc I have are both angle plug heads. It will be fun to see how this goes together. This is the 50cc engine:

 

Larry Trotter

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Nov 26, 2017
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I picked up the bike today. Yes you can tell It is a cheap bike, but the welds look nice and the paint is good, not bad for a bike that cost me $62.00 new. Now.................. the seat tube is more vertical than would be desired but is the right diameter for the mount, that puts the angle to the front tube a little steep for the china girl mounts. Probably not too bad as you can see. Definitely need to offset the carb some to get it to fit and I will notch the front mount adapter plate to let the motor set about a half inch lower. Looks like the muffler will fit just right and the cranks clear everything. I will remove the front derailer because the thing uses twist grip shifters and I need the right one for the throttle. No show stoppers yet, but clearly people are right that it is a tight fit in this frame. Larry
 

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Larry Trotter

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Nov 26, 2017
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I hadn't thought of those shifters, could be a good way to keep it. Not really sure how much use I would get out of it, has 5 speeds on the back so I could probably pick a front sprocket and just leave it there. I did put the rag joint rear sprocket on tonight, I was surprised how easy it was to get it straight, no problem at all. With the offset to the inside the chain clears all the parts and lines up very well with the motor, putting the tensioner on will give it good clearance on the bottom also. More pictures tomorrow. Now it looks like my biggest issue will be the intake manifold to get the carb angled out the right side of the seat tube. Larry
 

crassius

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Sep 30, 2012
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did you consider making 2 long studs for front mount to get rid of flat plate? if front too wide, then put a piece of PVC under it's sharp edge (with a groove filed in it to keep in place) under the flat plate
 

Larry Trotter

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Nov 26, 2017
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I think likely what I will do is cut a v notch in the plate so that it centers on the front tube and lets the engine sit slightly lower. that will keep it centered and locked down tight. I may bend the plate up some so it clamps to the tube properly. I am curious if there is any frame that these engines fit without any alteration in mounting. The front tube is far too wide for the front mount on the engine without the plate. Larry
 

crassius

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Sep 30, 2012
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motors can be ordered with either wide or narrow front mount (I always get wide as it is easier to make it narrower than wider), but many asshat 'stylists' want bikes that differ greatly from the norm
 

Larry Trotter

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Nov 26, 2017
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I have never seen that option, guess I will have to find out how to look for it. It would have been useful here, but the angle is still wrong between the tubes so I would still have to do some mods. I did cut the notch in the adapter and it will work good but I will need to get some different screws to attach it to the engine because the bolts I have hit the tube because it is too wide. I will post pictures of it installed. Larry
plate.jpg
 

Larry Trotter

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Nov 26, 2017
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To get the motor low enough for the carb to fit I had to shorten the rear mount that slips on the studs, milled off about 1/2 inch. Could have just cut it with a hacksaw and filed it flat.
rmount.jpg

Then I mounted things up and it is looking fairly good now, things are straight and solid, I will probably clamp the exhaust to the front tube just for a little extra support.

eng.jpg
 

Larry Trotter

Active Member
Nov 26, 2017
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1.jpg
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All finished up I think, I will post some lessons learned soon. Total cost is right at $160.00 Larry

PS: Yes it starts and runs.
 
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