27th Jan 2011, 11:12

Bought an 85 750 Maxim X last year. Took a while to get the tank and carbs all cleaned out. Replaced the petcock and had the carbs synchronized. Finding parts is not an easy task. Hope I never need anything vital. Got to love the look of her though. Has just under 30,000k, and hoping for lots more in the future. I am also looking for some cosmetic parts eg. chrome air box cover.

21st Mar 2011, 22:39

Hi, I'm Shannon.. and I have an 85 Maxim XJ700X. It is my first bike. It has a little over 27,000 miles on it. To get to your question, and I don't know if you will see this or not, since you posted over a year ago, but in case anyone else out there has this issue as well, I have carpal tunnel syndrome, and the vibration does the same thing to my throttle hand, so I went on Ebay and bought a "Cramp Buster", and it truly helps so much!!! Only paid 10 bucks plus shipping. Works great!! Have a safe day!!

23rd Mar 2011, 14:15


I just recently traded a XBOX for an 85 XJ700 X. I thought it was a good trade; even if I couldn't get it running, I could part it out.

I have a few questions that maybe some of you could help me with.

Is the pull rod in the clutch casing suppose to be a little loose? (it doesn't come out, just wiggles)

Why is the bike moving even if a gear is engaged?

Is it the drive shaft, or the transmission?

Where can I get a reasonable petcock for the gas tank?

Is there a universal one that will fit the tank?

Thank you for reading, and any help will be greatly appreciated.


25th Mar 2011, 05:54

Hi there, I'm a Maxim xj700 owner from Wales. I'm on my 2nd one; the first was stolen and never seen again...

To answer a question about the oil light coming on, but not starting... mine does this sometimes if the bike is in gear and the side rest is out. Check down by the side stand for the switch that lets the bike know your stand is down, maybe there is something wrong with it. Also check you're in neutral?

Hope this helps. Phil, Swansea.

10th May 2011, 13:43

I need some help from someone with practical knowledge of the Maxim. I have a 1985 Yamaha Maxim XJ700; and on the registration in the box labelled Model, it says "MS". I've looked everywhere on the bike for anything that would specify exactly what I have, and even ran a serial number search (which only came up as "XJ700") ; do I have a XJ700, XJ700N, XJ700NC, XJ700XN, XJ700XCN, or a XJ700XS? Because I'm trying to figure out which bikes have carburetor floats that are interchangeable. I'm also trying to find out if the 650's and 750's carburetor floats are interchangeable with the one I have; which has what I believe are 33mm Mikuni CV carbs. Any suggestions would be gratefully appreciated.

31st May 2011, 14:37

I believe the 700 and 750 models are the same, except the stroke has been shortened on the 700. 750's were only sold in Canada, so parts may be a little harder to find. I ended up buying some used bikes for parts. It is cheaper than buying parts out of a salvage yard.

26th Jul 2011, 22:02

I just bought an 1985 XJ700 Maxim X. My first bike. Had the same problem. First dump all the gas in it and replace with High Octane fuel, and add a small amount of octane boost. This will clear out whatever you have in the tank and loosen anything in your carbs. Then get some Seafoam with some high octane gas and run your bike. And do it all right the first time, change the plugs and the oil with the filter. Don't forget the air filter also. Most likely they ran the bike with bad low octane gas. It worked for me. My bike runs like new. Don't be cheap with the gas on your bike, use the good stuff, it's well worth it. Find a place that sells gas with no ethanol, and you're good.


6th Aug 2011, 01:48

Re. "Maneuverability may not be quite on par as the super-bikes, but she's very close to it."

I currently own (registered, inspected, insured etc.) about 15 bikes, and have owned well over fifty others in the past.

What especially surprised me about the MaximX when I got 'er back in, oh, 1999 or so, was that it's really a sportbike in disguise.

Go ahead & park yours next to a "serious" sportbike. You'll notice that the fork angle, footpeg placement, and even the handlebars are maybe a bit closer to a "standard", but NO WAY is it a cruiser, which is what it looks like at first glance.

I got mine with about 900 miles on the clock. It's had a hard row to hoe taking my riding time from all the other bikes, but I've still managed to start pushing 10,000 miles now.

It's a real kick to ride. Faster than one might expect for a now-25-year-old motorcycle, and handles much more like the bikes I used to roadrace (long, long ago) than any cruiser there ever was.

Anybody else notice the rear wheel? Only bike I can remember ever owning that looked SO different from right vs. left side. And it's the only "sporty" bike I've ever owned with SHAFT DRIVE (!)

13th Aug 2011, 13:59

Hey, check to see if your coil wire is not allowing the electricity to travel to that cylinder, that happened to me and I replaced the coil/wire.. Good luck!!!

7th Mar 2012, 19:03

I'm having the same fuel getting past the carbs. How did you fix this? Mine won't even start.

13th Mar 2012, 11:22

Join XJBikes.com. Invaluable endless information for Maxims there.

21st Apr 2012, 00:27

Even more Maxim-X information at "Maximum Maxim-X"... www.maxim-x.com

27th Oct 2012, 13:14

I have a MAXIM 700 N. It is a superb bike, but I have always had a carb issue. Next Thursday is C-Day (Carb Day). I am getting them "sorted".

The bike hates the wet - I get 1m down the road in the rain and it splutters.

40+ miles to the gallon.


18th Nov 2012, 14:31

"C DAY" went badly. Carbs still leaking on tickover. On the plus side, the new plugs I fitted the other day (after the old ones being in for just short of 3 years) have made a difference. She goes like hell from standing start. Still need to get the carbs balanced when - not if - I get the leak sorted.


7th Jul 2014, 22:08

Yamaha made 2 XJ700 Maxims. The XJ700X was the 4 valve watercooled engine.

15th Aug 2014, 05:30

I have been having the same problem. I found out it's that the starter isn't engaging after replacing my battery. It was doing the same thing. It seems the starter is going. I bought a new one, not a problem now; before I had to tap on the starter so it would engage.

Besides that, the Maxim has given me no problem.

26th Aug 2014, 20:10

Hi, I have recently bought a 1986 Yamaha XJ700 Maxim X 20 valve water-cooled, but I'm having trouble starting it. The battery seems to be flat and is unable to turn the engine over. The previous owner said they'd put a new battery in and it certainly doesn't look very old. I haven't tested to see if it's charging yet, but when it's running, a blip on the throttle makes the lights go brighter. I'm wondering if it's got a bad earth from the battery, which goes from battery and connects to engine, but it just doesn't look right to me, as though someone may have moved it sometime. Can anyone confirm the correct place to earth the battery to? I would have thought it should earth to the frame.

My other thought is if there is something draining the battery, as when I charge it to full, the engine turns over and starts OK.


27th Jun 2015, 02:47

Mikuni carb. diaphragms are available as a remanufactured part through Yamaha and Suzuki Owners' Clubs: both use BS/BSR36 instruments. I do believe the cheapest decent ones come from the FJ Owners Club - or look up FJ Racing to find an Internet link? You will have to join the club - but the savings you'll achieve on a set of 4 will more than cover the sub. cost!


24th Dec 2016, 03:50

Your starter solenoid is bad. I have the same problem. I just bypassed it with a toggle switch.

9th Jan 2019, 01:19

I have a 1986 Yamaha Maxim XJ700. I'm looking for a gas tank for it. The one I have has lots of rust holes in it. I tried to braze the holes, but I'm beginning to think it's a lost cause.