Fuel economy question.

[tat2]

Would old spark plugs be a contributing cause in the loss of fuel economy?
Pretty sure they are the orig plugs

Last year I was getting approx 250-260km (better on longer out of city road trips) before needing reserve.
This year I seem to only be getting 210-220km before needing reserve.

I noticed a bit of a loss in economy near the end of last year but chauked it up to longer warm ups in colder wether.

I have changed the air filter @ the beginning of the season, no changes were made to the carbs, other than being checked out if dirty & choke slide lubed). Valves adjusted. Ran a couple of tanks of seafoam with the first couple of tanks after buring off the stabilized gas.

Pretty sure my riding style hasn't changed, my commute is a bit longer this year (approx 30km one way, it was about 10 before) & most of my driviing is still within the city. Bike dosn't smell of fuel and the tip of the tail pipe is not extra carbony so I don't think I'm running rich.

Anything else I can check to get back my fuel economy?

BTW this is a 2K 600

[crazyaussie]

What about your chain and sprockets...is it maybe time for a changeout? Another thing I would suggest is keeping an eye on the tire pressures....a low tire pressure would cause poorer gas mileage. That's all I can think of right now.

[The CyberPoet]

CrazyAussie hit it on the nose: tire pressures and chain maint. A bad chain can suck up to 15% of your power before it ever reaches the back wheel.

The only other possibilities that readily occurs to me are:
1. The fuel you buy now has a larger amount of alcohol in it, so you are losing power in two ways - evaporation of that alcohol while the fuel is in the tank, plus lower power-output-per-gallon.
2. Bad carb float -- but this should be obvious as an increase in the oil level and/or a very nasty (& fluid-filled) airbox.

Oh, and spark plugs are pass/fail -- either they detonate the mix or they don't. If your bike was missing regularly, you'd be complaining of power-loss and explosions out the tail pipe (after-fires) or through the airbox (back-fires).

Cheers,
=-= The CyberPoet

[Timbercreek]

Could be my imagination but I changed over to Mobil 1 synthetic, sync carbs and adjusted valves and I gained around 4 mpg.

[tat2]

Mmmmm, maybe I am getting too heavy handed on the throttle.

New chain & sprockets over the winter as well, always lubed, cleaned & maintained regularly.

As far as tire pressure, I am on top of it regularly as well. Following Cybers recommendations I searched for long ago.

Not bad carb float, oil is fine (just changed) and the airbox is nice & empty.

[The CyberPoet]

Could be my imagination but I changed over to Mobil 1 synthetic, sync carbs and adjusted valves and I gained around 4 mpg.

Actually, this isn't uncommon. The oil may well be doing a better job and inducing fewer pumping losses.

Mmmmm, maybe I am getting too heavy handed on the throttle.

Could be. Or your new route may have a different kind of riding environment than your old one (more uphill stretches, more traffic stops & slow-downs, and/or more high-speed highway type riding).

Cheers,
=-= The CyberPoet