Your Capacity & Range?

Weather permitting I have been commuting with my 1980 XJ Maxim while having a lot of fun. I'm getting about 40 MPG accelerating quickly and cruising at about 70. I'm happy with the initial mileage, especially coming from a 32 year-old quad carb bike. I noticed that if I fill up the bike with it leaning on its kick stand that it begins to seep gas from the cap when I set it back up centered. So I've been keeping the fuel a bit lower than the cap and filling up with about 2.7 gallons. The fuel capacity is supposed to be 3.43 gallons, is the reserve part of that capacity with an additional gallon? I don’t fill up until I switch over to the reserve so my capacity is probably about 2.5 gallons. I can tell that I need to switch to the reserve because the bike begins to lose power. When I feel it losing power I reach down and turn the valve to reserve and the power comes back and I head towards the nearest Chevron. I don't mind not having a fuel gauge just as Iong as the odometer works and I know what to expect.

What is your experience, what is your range with the maxim tank? Is there a new seal kit I should get for the gas cap so I can fill it up all the way?

 

The 650 tank is smaller than the 750 tank. With my 750 I'm getting 40 t0 50 mpg depending on who is riding it (me or my wife). The 750 tank size is about 4.75 gl and when i hit reserve there is about .8 gl left in the tank. I just fill up between 160 and 175 miles or when I hit the reserve (whichever comes first)

The 3.43 gl for the 650 is from empty, so when you hit the reserve you have about .8 gal left in the tank (maybe a little less)

I believe the 750 tank is a direct swap with the 650 (Maxim to Maxim) but only the 82 750 has a sending unit and then you would need to get a gauge that works with it.

 

Thanks Ty, I sure appreciate your help.

I figure if I can stop treating each on ramp like the 1/4 mile then I should eventually get 45 MPG. For now it's just too fun going anywhere fast.

 

What Tcoop said is pretty much my experiance as well. Minus the wife riding the bike.

I changed to a 750 tank. Bolted right on. Also I have a right up here to make a LED fuel gauge with any sender you want to use.

 

And yes, there are rebuild kits available for the gas cap. It's most likely the seal, but there are a couple o-rings and a ball valve in there also.

Head on over to the XJ4Ever web page.

Schmuckaholic did a PDF file on gas cap rebuilds that you can download from there.

(Along with a bunch of other neat write-ups)

 

I've got an 81 650 Midnight Maxim and before I started rebuilding it I was getting 48-49mpg combined, average speed 50 mph. I too love hard acceleration and taking turns at a lean, and with the 650 tank I was putting around 2.5 gallons at a time in. This was getting me 120-135 miles before hitting the reserve, but I rarely let it get that low for fear of sucking in muck in the bottom of my tank. I was filling at 100-120 miles. Now that I am nearly done a complete rebuild I will have to see what my mileage and distance numbers look like.