Reserve Capacity for 78 KZ1000A2?

I did some scratching around before posting this ?, but couldn't find a good answer. Anyone have hard numbers on what the cumulative total & reserve segment is for this bike?

Reason I ask is...I seem to be getting about 125 miles before switching to reserve and, at fill-up, am generally finding exactly 3 gallons fuel used. I've done some engine mods & that's with carrying weight of 300lbs +/- and general traveling speed of around 75...so I really have no complaints about that mileage.

However, I always assumed that the reserve was puny. But I believe specs show tank size as 16.7 liters. Which, by ye ol web converter, should be about 4.4 gallons.

If I generally find myself switching to reserve 3 gallons down, that would make my reserve nearly 1.5 gallons. Which can't be right. But I sure would like to know if I have that sort of headroom!

Of course -- I can test it on a looming trip as I'll have a buddy w/ an old Guzzi. Larger tank + hand siphon will certainly yield a hard answer .

Occam's Razor would probably suggest that I'm swapping to reserve far too early and based on expectation more than necessity.

Boneheaded or not, I'd still like to hear any/all weigh in....an additional 30-50 miles of range sure would make a difference on a long haul.

For 1977 KZ1000-A1, FSM says 16.5 liters total, including 3.6 liters reserve. Which equates to 12.9 liters "main" tank plus 3.6 liters reserve.

For 1978 KZ1000-A2, FSM says 16.7 liters total, but doesn't provide a specific reserve capacity.

Thinking the '77 and '78 tanks were virtually identical except for paint color, I can't explain the additional 0.2 liters in 1978.

May verify the FSM figures as follows ---

With engine off, bike level, fuel level above reserve, and supplying vacuum by other means to petcock in ON position, could drain tank into separate container until "main" tank empties.

Then use a separate calibrated container to finish draining with petcock in RES position.

When on the road and RES is exhausted, might gain an additional mile or so by standing on the pegs and pumping the forks to jostle remants of fuel inside tank to petcock. At least this works on 1973 Z1 and on KZ900-B1 LTD.

Good Luck!

1976 KZ900 FSM says 17 liters (4.5 U.S. gal) total, including 2.1 liters (0.5 U.S. gal) reserve.

Again, I can't explain the difference in total capacity between '76 and '77. But the '76 manual petcock likely accounts for the different reserve capacity due to different pickup tube length(s) extending up inside the tank.

Good Luck!

The original 1973 Z1 OWNER'S MANUAL (delivered with a new bike) says 4.7 U.S. gal. (18 ltr) total fuel tank capacity, of which reserve position provides 1 gal (4 liters) fuel supply.

After burning through a tank or so from full to reserve, the odometer becomes a good indicator of miles remaining.

My 1976 KZ900-B1 LTD regularly hits reserve (from full) at about 120 miles. And I routinely reset the odometer at every fill-up. The FSM says 13.6 liters, 0.8 liters of which form the reserve supply.

Good Luck!

dont forget about the LTD tank, it is smaller, mine has a cap of 3.2gal, I only get about 100 -120 miles before hitting reserve

don't know about you fella's z's and kz's but my z1r won't make it out of site of the place where i "hit"reserve.i ran out a couple times being "overly optimistic".a little reserve gas can might not be a bad idea on along trip.

leon holmes

Thanks much fellers....now I'll have plenty of miles and refill repeats to crunch the numbers and see what's what.

Will report back.

interesting topic because I have been thinking about changing my fuel tank to get more capacity. Looks like I could go to a '78 and add almost another gallon.

does anyone know if a '78 A2 tank will fit on a '80 G1 frame?

The 550 standards have two tanks that look identical, but have different capacities. The difference is not visible while the tank is on the bike. But if you flip them over, one tank has a narrower tunnel for the frame. This also has less clearance for the coils etc. under the tank.

The earlier tanks held more, but the newer tanks have more clearance for coils. I believe the difference was to get more air to the coils to keep them cooler, but that is just a guess.

This goes the opposite of the 1000 tanks where the earlier tank holds less.