21st May 2011, 02:46
No unleaded is fine, you should run 93 octane, but 87 is OK; I just find it runs smoother on higher octane..
22nd Jun 2011, 14:51
I just starting working on a 1980 Yamaha Maxim 650 that had sat under a tarp in Indiana for years.
After going thru the carbs, and cleaning the tank and petcock, it would not idle on its own until I discovered the vacuum line from cyl 3 carb manifold to fuel petcock was disconnected and flopping in the breeze. Runs good now, and idles all by itself.
27th Jul 2011, 13:49
Hi, I'm wondering if you did ever fix the second gear? I have the same problem here with my XJ650. I can skip the gear, but it's annoying when it's grinding in second. Anyways, let me know, thanks a lot.
30th Jul 2011, 13:48
They stopped making motors that needed lead in the early 70s. An 80s should not need it. But I'm no pro.
21st May 2012, 16:20
The bike was designed to run on leaded gas and I was using an additive as well, at first. What a pain that is, but I stopped using the lead additive, and have used unleaded gas in it for the last 5 years, and haven't had any problems. It runs great and goes very well. I also run premium gas in it. I think I read once that the lead is supposed to keep the valve guides from scoring or wearing, or something to that effect.
21st May 2012, 16:47
I had a Maxim that had the same 2nd gear shifting problem. I don't remember exactly what the fix was, but it is an easy fix if you just do some research. Something about a shifting fork broken or a broken spring. That was years ago. Pull the side cover off with the shifter shaft sticking out and it should be right there. I bought the part from a local dealer years ago. Yep, it was a spring. Easy easy fix!
I still ride the Maxim every chance I get (yesterday). I love the bike, in fact, I have two.
When I first got my 1980 XJ650 Maxim from a friend for $140, I rode it home and thought that it needed cleaned up. So, I took it apart and quickly realized that it would be a while before I would have it done, so I bought a 1981 XJ650 Maxim on eBay for $400. I'm still working on the first Maxim and still riding the other one. New tires, chrome, King/Queen seat, along with polishing the aluminum. Still not done, but it looks good. :)
20th May 2018, 14:50
I completely agree. My friends have newer V-twins with larger engines. My 650 Maxim blows them away at every stoplight easily, without even trying.
It will cruise easily at any speed up to about 80mph, after which it gets a bit high in the revs. Good handling and a nice, simple bike overall.
27th Feb 2011, 20:32
I have owned my 1980 XJ650 for 24 years. It was my only ride for about 10 of those. Kids and life found it parked in the shop for the past 6 years. But the gas price has it back on the floor. A carb rebuild and some really good polish has me in awe of this machine. I've dropped it twice, and once was at high speed with rain and sharp curves, it will not stop. Please run it often if you can't ride it, the carbs will not drain by running the tank dry. After 31 years and some parts from an '82 model, this bike still turns heads. Safe riding my friends.