Pw50 motor to qt50

Has anybody changed the motor from a pw50 to a,qt 50..if so what differences did you encounter.i read the qt50 has a charge coil since it has a battery.the pw doesnt so will i need to change out the stator assembly.any info on this is appreciated..thanks

Re: Pw50 motor to qt50

Angry Hipster /

I don't think the wiring would be the issue. I think it wouldn't just bolt up, that's why people swap the gears instead.

Re: Pw50 motor to qt50

The motor on the pw50 looks identical to both the qt50 and the towny..i havent done any measurement but they all 3 looks as if they bolt up in the same places and the drive shaft looks the same on all 3 ..the wire connection out of the stator looks like it is the same on all 3 .all of them have the same carb..i am almost sure they will swap but not sure of the wiring since the pw doesn't require a battery and the other 2 do.

Re: Pw50 motor to qt50

Jack Rutherford /

should just bolt right in. I think the lighting coil is different on the stators and not the charge coil.

Re: Pw50 motor to qt50

Should go in the QT, get the gear from the rear end too, ;) I think the Towny is a different beast, 2spd? Not 100% on that.

Re: Pw50 motor to qt50

> Jack Rutherford Wrote:

> -------------------------------------------------------

> should just bolt right in. I think the lighting coil is different on

> the stators and not the charge coil.

Thats what has me a little confused..i don't want to hook it up and burn any coils out ..the qt has had some wiring done and the plug has been cut out of the harness ..the towny still has the wiring original..i have about decided to go with the towny for the swap and save the qt for another day .

Re: Pw50 motor to qt50

> Stephen Keller Wrote:

> -------------------------------------------------------

> Should go in the QT, get the gear from the rear end too, ;) I think the

> Towny is a different beast, 2spd? Not 100% on that.

I just noticed about being 2 sp..i haven't done much reading about the towny.it was just a thought today after noticing the motors looked the same..i guess i need to look into the 1 or 2 sp .

Re: Pw50 motor to qt50

Google Yamaha Towny I just did, it is a 2 spd, there is a wealth of info there, including some articles and trouble shooting tips, I think the Towny engine trans would go on the QT but have not read enough to see if it would go the other way around.

Re: Pw50 motor to qt50

I had intended to do some research and i appreciate the info...i just have the pw50 that is a left over from me putting my grandson on a kx85 a couple of years ago..i cleaned the carb and started it today.thought i would switch it over on one or the other for the girls to ride ..3 hard years from my grandson has the pw needing a good going over in shocks brakes and a few other things but the motor starts and runs as good as ever.both the towny and the qt are supposed to run but have been sitting for some time so just a thoughtbto make a quick rider for tge girls while check out the motors(edited)

Re: Pw50 motor to qt50

Get the QT going first, the Towny can have frame issues, QT is simple and rugged. Towny is kind of a unique bike, from what I read, it seems wise to keep with stock stuff for it. I LOVE my QT, just wish I could get 5 more mph out of it, but I guess I could diet... :D

Re: Pw50 motor to qt50

The qt is ptetty nice shape but going to have to figure out what they have done with the wiring..has no battery and i haven't been able to see what needs to be put back on it to add the battery back.it has no battery box that i can find..the towny is very clean and original

Re: Pw50 motor to qt50

The battery goes behind the seat, it can still sit there without the cover, the service manual can be downloaded. A lot of people part these out (QT) maybe advertise for a harness? If you can't find the manual I would share my paper one, if you promised to send it back... :)(edited)

Re: Pw50 motor to qt50

If the battery has a small red wire going to it i saw where there was one cliped off and taped .i dont have a plug there if it takes a small battery like the towny.i havent looked at it much and will have to look at a diagram when i start with the motor swap

Re: Pw50 motor to qt50

As I said if you need the manual, happy to share, but I know it is on the web somewhere. T think there is a red wire somewhere, they are small batteries, my Express has one too, not ridden the QT in a long while but it will run without the battery, but brake/tail lights and directional s may not work, headlight should run from the engine alone. Also note the start run key position if your bike has this, in the start position the engine will start, but not rev, once running switch to run, then you are ready to ride, silly safety feature, '79-'80 did not have this but later models do.

Re: Pw50 motor to qt50

Thats a very nice offer on the manual.not many folks would offer that..i think i can make it with the wiring from a diagram i got in the wiki..i wouldn't mind seeing a picture of the battery box and connection there so i know what to get to put it back original..running it without a battery was one of my concerns also because i read the battery keeps the voltage regulated so it doesn't burn out the coil,so wanted to put the battery back in the mix if that is the case.the pw has that start option on it also.(edited)

Re: Pw50 motor to qt50

Angry Hipster /

Re: Pw50 motor to qt50

I've swapped QT50 onto a towney frame.

Going from QT50 to PW50 you're gonna need to:

1) swap out the drive shaft assembies. From your QT50, use the rear shock, wheel, rear hub, and drive shaft. This will ensure you have the right final drive ratio and engine+wheel geometries fo the handling doesn't get any worse.

2) The wiring is almost certainly different, you may need to swap the stators cause PW50 doesn't have lights. Yamaha flywheels have a puller unlike most other mopeds, but they are easy to buy online.

3) throttle cables may be different. Use the PW50 throttle cable, caburetor and airbox.

4) a towney motor cannot be easily mounted on a QT50. Transmission parts for towny's are not availible. Towny has a different exhaust thas not compatible. Id stick with the one speed motors so you can fix/maintain it easily.(edited)

Re: Pw50 motor to qt50

I had the towney swap on my mind to start but droped that when i found it to be 2 speed ,so the swap went back to original plan of pw50 motor going on the qt50....my concern is the differnt electrical so that is my main concern figuring out for sure what if any electrical components i need to swap..as for gears i will just leave whats in the qt .i had read before the part about the battery being or acting like a rectifier or regulator .was hoping somebody had made the swap and new from experience..

Re: Pw50 motor to qt50

Jack Rutherford /

I put pw50 charge coils on my qt50s all the time. The difference is the light coil.

If you want to run the lights, you'll need a qt50 lighting coil. The easy thing to do is put the qt50 stator in the pw50 engine (then the stator will have the right 4 plug connector and the proper lighting coil - see below).

If you are putting a pw50 engine on a qt50 then the connection from the stator to the wiring harness is different (see above). You can easily just make them all single wire connections instead of using the 3 or 4 prong plugs. The battery does act as a regulator but if you have a qt50 with a 3 position switch then there is also a separate regulator on the frame. If it were me, I would just strap on a battery because the battery provides power to the turn signals, horn and brake/tail light.(edited)

Re: Pw50 motor to qt50

The plug has been cut off and wired direct on the qt50..i will have to check the wiring diagram when i get started .i had planned on working on it today but got side tracked on a buying spree and brought home a couple of rescues . A western flyer and another columbia...i appreciate the info..my problem is beginning to be buying too many and no time to work on what i have already..it can be a nightmare obsession i think .(edited)

Re: Pw50 motor to qt50

^ Lol, yeah mopeds can ruin your life! But a guy could have worse problems.

Re: Pw50 motor to qt50

Problem is begining to be i have a bunch more peds than grandaughters..wife has been sort of ok with the buying spree but i think she can add better than i thought ..starting to think i might have to sell a few or get more grandaughters ..

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