Yamaha QT 50 "Noped" project

[outskirtscustoms]

Here's another tidbit of info

http://en.wikipedia.org/wiki/Yamaha_QT50

 

[yoothgeye]

Here's another tidbit of info

http://en.wikipedia.org/wiki/Yamaha_QT50

Thanks, I've actually read that Wiki article a couple times.

I just took the bike further apart, wheels off, fork off, engine/swingarm off of frame. I may run it by the motorcycle shop tomorrow to get my mechanic friend to pull the flywheel so I can get to cleaning it up.

I removed the oil pump from the bike and am trying to see if others who bypass the oil injection have removed the pump or just leave it there. I am thinking of making a plate to cover up where it goes into the gear box or if for some reason it needs to remain in place.

 

[yoothgeye]

Yesterday I had some time so I took the fork off the bike, turns out it has loose ball bearings in the head set, so after gathering all those I started to remove the oil pump. The bike was already a unicycle, so I unbolted the rear shock and the 1 engine mount bolt.

At this point I had a motor with rear wheel attached sitting on a kickstand.

I eventually removed the rear wheel. I need to clean out the drums and will probably put some shoes in it before putting the wheels back on.

I poured Marvel's Mystery Oil in the crankcase and let it sit overnight.

At lunch I grabbed the engine and carried it to the motorcycle shop. When I got there the mechanic pulled my cylinder and head from under his work bench. Cylinder honed, piston blasted clean and reinstalled in cylinder, and head sandblasted clean. There is some pitting in the upper part of the piston, but he said he would just put it together and get it running first, worry about new parts later since the piston and rings are in such good shape.

Then I went out to the truck and got the engine, I knew he would have a flywheel tool, so he got the tool and removed the flywheel, then used his impact driver to get out the magneto so I can clean it all up.

When I got the bike it didn't have a nut on the flywheel, I asked if the threads looked too far gone to thread a nut on. He grabbed a die and chased the threads on the crank and produced a new nut and spun it on.

Things are going well!

 

[LukeTheJoker]

Sounds like you have a great friend there! :wink:

Luke.

 

[outskirtscustoms]

Yeah it must be nice having thousands of dollars worth of tools at your disposal. What would take me a month with my primitive hand tools would take someone else 5 minutes on a lathe or 30 seconds on a CNC machine.

 

[yoothgeye]

Sounds like you have a great friend there! :wink:

Luke.

He is.

Yeah it must be nice having thousands of dollars worth of tools at your disposal. What would take me a month with my primitive hand tools would take someone else 5 minutes on a lathe or 30 seconds on a CNC machine.

Yeah, he just did it in a few minutes between other jobs. When I am there he is constantly rolling one bike or quad off the lift and another back on. Also, he doesn't do unnecessary repairs and goes out of his way to fix little things instead of the easy way to replace big things. Also helps customers fund used parts. It's not his business, but he is a great asset there.

 

[dracothered]

Re: Yamaha QT 50 "Noped" project

This might be a fun direction to go with one of these QT50's.

 

[yoothgeye]

Re: Yamaha QT 50

This might be a fun direction to go with one of these QT50's.

Lots of mopeds would easily lend themselves to that look better than the QT50 since mine is shaft driven. Chain drive opens you up to more options, but I like the shaft drive for (fingers crossed) a more dependable driveline.

 

[yoothgeye]

I've been working on a few bikes for myself, for kids, and for friends lately, so the moped has seen very little attention. But last Thursday I did get to weld in a top bar to mount the tank. This is not a structural piece, but it is pretty strong.

The top of the stool it is sitting on is a skateboard deck... yes, this frame is tiny.

 

[LukeTheJoker]

Are you going to fit on that thing?

Luke.

 

[yoothgeye]

Are you going to fit on that thing?

Luke.

Well, I fit on it stock, but I didn't like the position, sitting straight up, knees at a 90 degree, elbows back beside you. Looks goofy. By shifting the seat back where the original rear rack was I will lean forwards towards the bars and have my feet out ahead of my knees. That being said, I'm sure I will still look too big for it.

The GVWR is in the manual at around 270 pounds. Given my 200 pounds, and the bike's stripped weight at 68 pounds, when this thing is done, ONE of us is going to need to lose some weight.

 

[g-ratter]

There seems to be a flat spot in the frame were the engine mounts. You could probably stretch the frame some for a better fit???

 

[yoothgeye]

There seems to be a flat spot in the frame were the engine mounts. You could probably stretch the frame some for a better fit???

I considered it, but my layout should look proportional (I saw one stretched, not a fan) and I like the short wheelbase. Plus, stretching the frame would mean redoing the wiring harness... no thanks. :lol:

 

[yoothgeye]

Last thursday I filled the tank with vinegar and let sit for a few days. Today I wet sanded the inside of the tank (equal parts sand and distilled water, shake vigorously for 15 minutes). The inside of the tank looks great, but while sanding a pinhole appeared, and during drying I identified about 6-7 pinholes total. Not sure where to go from here. I love this tank, it fits perfect and the price (free) was just right. A similar or the same tank on eBay will be $50-$150 bucks!

 

[outskirtscustoms]

Last thursday I filled the tank with vinegar and let sit for a few days. Today I wet sanded the inside of the tank (equal parts sand and distilled water, shake vigorously for 15 minutes). The inside of the tank looks great, but while sanding a pinhole appeared, and during drying I identified about 6-7 pinholes total. Not sure where to go from here. I love this tank, it fits perfect and the price (free) was just right. A similar or the same tank on eBay will be $50-$150 bucks!

JB weld. I have used it on scooter gas tanks before. :wink:

 

[yoothgeye]

JB weld. I have used it on scooter gas tanks before. :wink:

Exact answer my brother-in-law gave me and I just looked up some information on another forum by people who have been using JB Weld for tank repairs for decades, with repairs being decades old and still holding.

The only suggestion was to use the original JB and not the quick dry. Even though the dry tensile strength is the same, the quick dry doesn't "bite in" and adhere as well as the original.

 

[outskirtscustoms]

The tank on my scooter I've got now was repaired with JB weld and it's holding great. :mrgreen:

 

[outskirtscustoms]

Just a thought...

 

[yoothgeye]

Ummmm... No.

Haha.

Ever since I welded the top bar into the frame and found the holes in the tank, I haven't done any more work. Been fixing up a lot of kids BMX bikes. On top of working on this thing I am in search of a real moped.

 

[yoothgeye]

The QT is still in pieces, I have welded on a rear post for the cafe racer style seat, but I have come upon some things slowing me down, choke stuck in carb, and ummm... parts everywhere. haha

So last night I picked up this 1985 Puch Maxi S for $100: