Is it worth it to install this motor?

[ih82lose]

Hello everyone. I have a 1992 36v Marathon that I am bringing back to life. As far as I know, the stock motor is in working condition. While I'm in the process of looking everything over, I came across a Yamaha golf cart motor that I bought about a year ago. From what I can tell, it has the same splines and mounting as the EZGO motor. So, my question is whether it would be worth swapping in this over the stock motor?

I haven't been able to find clear specs on the original EZGO marathon motor, but have attached a pic of the plate on the Yamaha motor. Looking to the collective knowledge here to see if it would be worth it to swap in the Yamaha and gain some MPHs. Thanks for the advice.

[JohnnieB]

I don't know if that motor will up the speed any or not, but if it fits mechanically, it won't hurt to try it.

Two things I see on on the label:
1. Max safe RPM is listed as 8000. That's good.
If you upgrade to a 48V battery pack, you aren't likely to exceed 8000 RPM

2. Class F Insulation. That's bad. (Your EZGO motor is probably Class H)
Basically, the Yamaha motor pictured is about 13% less heat tolerant then your EZGO motor, so you'll have to keep that motor's case temperature under about 200°F.

[cgtech]

Will get no speed increase, lower heat rated insulation, sounds like a nice downgrade to me .

[ih82lose]

Ok. Thanks for the info! Just had it sitting around, so thought I'd check.

Out of curiosity, is the stock EZGO marathon 36v motor specified to run at 2800 rpm? I thought I read that somewhere.

[JohnnieB]

Originally Posted by ih82lose

Ok. Thanks for the info! Just had it sitting around, so thought I'd check.

Out of curiosity, is the stock EZGO marathon 36v motor specified to run at 2800 rpm? I thought I read that somewhere.

Unless otherwise identified, the RPM on a motor label is probably the RPM at with the HP or kW rating listed on the label is measured or calculated at, however unless that rating is specifically identified as the Max Power Point, all you have is a point somewhere on the Torque/Speed curve.

What determines how fast a motor will propel a cart depends on the RPM vs Torque curve of the motor at the voltage being applied and without knowing what the Stall Torque and the No-Load loaded RPM for both motors, which one will propel the same cart faster isn't a certainty, but a guess.

Of course, you can try it and find out for sure.