250S/L: Gas Guzzler Extreme

[Darrell]

My 250SL empties it's 4.1 gallon tank in about 120 miles of conservative riding, mostly highway riding to our destination and then a mix of unpaved roads and trails. By way of comparison, my Hodaka drinks all the other bikes I ride with (modern four-stroke Dual Sport bikes) under the table.

Compared to the latest Kawasaki KLX 250s (with a 2.0 gallon fuel tank capacity) that I ride with I'm nervously returning to civilization on fumes while they haven't yet switched on to reserve. At the end one recent ride, I could only squeeze several ounces from the tank.

Seventies vintage Japanese 250 enduro specifications from the Big 4 read basically the same as the 250S/L as far as carburetion, compression ratio, performance, etc. The Yamaha DT, Suzuki TS, et al., came with average tank sizes of 2.5 gallons, versus the big 4.1 gallon jug on the Hodaka. Wasn't the (claimed) mileage of a mid 70s road/trail at least 50 mpg? Perhaps the extra capacity is a compensatory measure taken for the Hodaka so it could equal the distance between fillups of the competition?

I'm just curious why the SL could be prone to imbibe gas to excess. I've done all I know to help curb its appetite, e.g., proper jetting, clean air filter, staying easy on the throttle, etc. And its probably too late to file a complaint with the EPA and launch a class action lawsuit on behalf of Trail Whale and ThunderDog riders . Just kidding about that !

[Bullfrog]

I remember the report of a discussion with the factory engineers which went something like:

PABATCO "Why is the fuel tank so incredibly large?"
FACTORY "Because America is a very large country . . . 100 miles between gas stations . . . need 5 gallon tank!"
PABATCO "Then why do the 250cc Yamaha/Suzuki/etc models have 2 gallon gas tanks????"

(presumably, some accomodation for "styling" had already been made since the tank was only 4.1 gallons)

Ennnnneywayeeeee, the mileage you are reporting is no surprise to me based on the story above.

Ed

[hodakamax]

Darrell, after owning a couple of Yamaha RZ-350s set up for road racing, it sounds like you're getting great mileage.

Max

PS--It seems all two strokes are very thirsty. Sounds normal to me!

[relic]

Ok, so this maybe apples to oranges and all that but my experience with a Yamaha DT400C ('76 twin shocker) may be of interest?
This bike is my daily rider this season and I've logged 4000 miles on it since May. (plus a few more in previous years) I record every fill up and calculate my miles per gallon every so often. (no I'm not anal, just interested, LOL)
Sometimes a tankful will be consumed strictly commuting and playing on the gravel back roads at speeds that probably average 35 -40 mph. In this case I routinely see around 50 mpg (Canadian gallons) so converting to U.S. gallons this is about 41mpg.
However when I run a tankful down the highway at an average speed of 55-60 mph I can expect only mid to high 30s mpg Cdn or low 30s/high 20s in U.S. gallons.

My point is---you mention some highway to get to your riding area. Depending on how much highway running and how fast you ride and your gearing, (sprocket sizes) this could account for a lot of your consumption.
Add the info the others are providing re the 250 SL's apparent reputation for thirst and what you are experiencing is maybe quite normal.
In the past I had a Suzuki DR650 that scored close to 60 mpg unless severely flogged and my mighty TW200 Yamaha got 80 to 90 mpg so comparing to 4 strokers is futile. They will always win this debate. But two strokes are so much cooler!

Here is my answer to low mpg and a two gallon tank ---

Relic

[racerclam]

One must consider that the yamaha is a reed valve engine and much mor efecient than a piston port engine , also the Hodaka exaust is veery restrictive and also holds alot of heat in the engine makeing it very prone to detonation.

Rich

[michael_perrett]

My 175SL will run 40 - 45 mpg when riding at 45mph, will drop to the high 30's when running 50-55 mph. Still ranks as one of my most favorite bikes, along with my 1979 Ducati 900SS

Mike Perrett

[Darrell]

I remember the report of a discussion with the factory engineers which went something like:

PABATCO "Why is the fuel tank so incredibly large?"
FACTORY "Because America is a very large country . . . 100 miles between gas stations . . . need 5 gallon tank!"
PABATCO "Then why do the 250cc Yamaha/Suzuki/etc models have 2 gallon gas tanks????"

(presumably, some accomodation for "styling" had already been made since the tank was only 4.1 gallons)

Ennnnneywayeeeee, the mileage you are reporting is no surprise to me based on the story above.

Ed

###

Hah! I thought there would be a Story Behind the Story!

After reading that vignette of historic Japanese-American industrial relations, from now on I'll see that fat wide 250SL fuel tank - swallowing gas like there's no tomorrow, as a symbolic moment in the history of cooperative economics and negotiations between two great nations .

In enney event, I have experienced rapid tank drain (< 100 miles) especially when the greater portion of the ride is 55-60 mph on the highway, as is the same experience of other posters. It's also been suggested that my experience doesn't wildly deviate below the norm, so to compensate I'll either carry extra premix, or at least some Yamalube to add at a gas pump.

As one of the KLX riding buddies said in defence of my 250SL's appetite: Being cool has to have a cost attached somewhere. Are you seeing your fuel tank as half empty or half full?

Darrell

[RichardMott]

Darrell,

Your statement about the tank being half full or half empty is one I usually answer with an Engineering response;
"You have the wrong size container (Tank)"