QS138 70H V3 Motor Improvements

[DonCox]

The QS138 70H V3 motor has been a strong and reliable motor for us DIY builders. They have just made some significant upgrades to that motor. Here is the information from the AliExpress website. It is hard to differentiate the new from the old. They list and explain all the improvements on the included AliExpress link. The improvements include better waterproofing, bigger bearings on most bearings, bigger gear in the gear reduction, different cables for waterproofing, and I think a little more "beef" in the gear reduction case. You can identify the new motor by the new cover on the encoder side of the motor, (better waterproofing), and the nub that got near the output sprocket, is now gone. If you order thru AliExpress, and I have a lot, be sure to always use the best shipping method, DHL or FED EX. Always click on the Delivery box to see your options. Also to learn more about all the improvements, scroll down and click "View More" and they have great explanations.

https://www.aliexpress.us/item/3256801329527065.html

 

[bayodome]

Thanks for the info, Don! Not huge changes but certainly some improvements. Things have come a long way in the last few years.

 

[DT36]

The QS138 70H V3 motor has been a strong and reliable motor for us DIY builders. They have just made some significant upgrades to that motor. Here is the information from the AliExpress website. It is hard to differentiate the new from the old. They list and explain all the improvements on the included AliExpress link. The improvements include better waterproofing, bigger bearings on most bearings, bigger gear in the gear reduction, different cables for waterproofing, and I think a little more "beef" in the gear reduction case. You can identify the new motor by the new cover on the encoder side of the motor, (better waterproofing), and the nub that got near the output sprocket, is now gone. If you order thru AliExpress, and I have a lot, be sure to always use the best shipping method, DHL or FED EX. Always click on the Delivery box to see your options. Also to learn more about all the improvements, scroll down and click "View More" and they have great explanations.

https://www.aliexpress.us/item/3256801329527065.html

Hi Don,
Can I ask where you got your QS138 template from on your CR build pictures, please?
I've done a quick search, but nothing popping up, although I have seen a small drawing, but it loses sharpness when enlarging.
Thank you in advance,
Dale.

 

[DonCox]

Absolutely, glad to help. Lithium-king.com had them made for me. What year CR is your bike. If you go to his site, he has some models already drawn up for the water jetting. With some simple measurements, he can have them made for you. The precision is not exact, and some holes had to be adjusted slightly.
Here are some pics of the mounts he made for me. I had to offset the left bottom mount to get the sprocket in an absolute line.
I hope this helps, and if you want any other info, just ask, I love building these and helping others. I just helped Kenny Roberts build a mini flat tracker with the same motor and controller. Here is a short YouTube. I adjusted the tune the next day ( maybe a little too much), and he looped it out. Boy it took a bunch of alcohol to fix his ego...

 

[DT36]

Hi @DonCox and thank you for the prompt reply, although I think I slightly confused you.
I was curious to the cardboard motor drawing you used, which I've now attached below.

My Honda is a little bit older than yours, being a 1976 MR250 Elsinore.
It is a total barn find project and needs a lot of love. However, it will give me something to do and keep me out of trouble.

New plastics are easy to come by and will order soon. Just received a newer seat and ordered new cover today. Main issues with the bike are a seized engine, no carb and fuel tank is heavily rusted internally and pin holed. I can repair all those in time, but will come to around £1,500 GBP / $1,900 USD. To that end, I'm strongly toying with the idea of going electric on it, as I need to spend out with either option. I will still rebuild the engine, even if I go the electric route.
I plan on 3D scanning the original airbox if it needs modding, so all original parts are kept safe and unmolested. More than likely going to swap the tank out for a 1978 CR (Clarke) while eventually repairing the original over time. Pic added below to show one fitted to a 76 Elsinore.

Space wise, the Elsinore looks to have a lot more frame space than a modern CR and also the twin shocks are also out of the way, compared to a mono. Doing mostly research here at the moment and watching some of the build videos from you guys. Me and Grancha's Apprentice have started to strip the bike now and engine will come out this week.

Last big Honda I had was an 83 CR480 when I was younger, with my last bike being a DRZ400 about 10 years ago.
Was constantly getting pulled by Police and Wardens on that bike, even though legal as it was fairly loud. Being much older now, I think electric will allow me to ride sensibly close to home without attracting undue attention and having my picture posted up on my village social media platform

Thanks again for the help so far.
Dale