Mods for Longevity and Fuel Efficiency

[Yagenta13]

So, I see most guys mod'ing their bikes for more power (generally speaking). Bigger pipes, ram air, even turbos in extreme cases.

What kinds of mods would be appropriate if power wasn't the goal but the best gas mileage and most longevity for the engine were the ultimate goal? My bike is a 1300 CC V-twin with a carb so what kind of things could I do to get a efficient and reliable bike versus a bike that puts out max power?

Just bear in mind I can't convert my bike to diesel

 

[FL_Rob]

An economy cam grind ,nice and mellow not lumpity lump,closer to stock pipes (a little backpressure helps in this case).Do they make carb spacers for bikes, to increase intake velocity?look into that.Rely on the torque of that 1300 to move you down the road ,not revs ,sure it sounds good to get on it,but thats fuel makin' that power.Weight savings wherever you can,and of course proper maint.Quality oils ,full tune-up,etc.

 

[Yagenta13]

Not sure about the carb spacers but I'll research it a bit. If I had the money I'd love totake two identical bikes and have two teams try to get the most MPG and ultimate miles out of them. I'm thinking my VTX 1300 could potentially get close to 60 MPG and make it to 300,000 miles...

 

[eljefino]

Fitting an o2 sensor, preferably a wide band one, will give you feedback on your tune. And less gas in your oil is a good thing.

Most people tune their bikes by looking for instant response from idle when they rev. This can lead to super richness everywhere else, depending on carb design.

Depending on what brand bike you have you might be able to find an ignition box with different curve, or a part-throttle vacuum advance, lots of mixing and matching. Regearing the sprockets will probably help too, 1300cc can push one dude without a lot of revs.

 

[boraticus]

Personally, I doubt you'll be able to get too much effect from any efforts to de-tune the bike. There's not a lot you can do really. Most modern Japanese bikes equipped with CV carbs are tuned pretty lean from the factory. The bike comes with a 38mm carb. You could try a smaller main jet or even a smaller carb but that sounds a little restrictive to me. One 38mm carb isn't that all that big for a 1300cc engine. My KLR650 uses as 40mm carb and that's half the displacement.

Being that the VTX is shaft driven, you'd have to either get your hands on some different gears (if available) or have gears made to change the gearing. That would be expensive.

Personally, i think the best thing you can do to achieve your goal for fuel efficiency is to moderate your right hand activity. Throttle action can have a huge effect on fuel efficiency. Proper tire inflation helps. Keeping speed reasonable is will also help with mileage.

If you do proper maintenance and keep everything well lubed/adjusted, the bike will last a very long time. Fresh oil in the engine and annual gear lube changes in the shaft drive, grease zerks if you have them. Keep all fasteners good and tight. Make sure the radiator is kept clear of debris. Flush the coolant every couple years and also flush your brake/clutch fluid while you're at it.

Check out a VTX site. I'm sure there are people there with lots of info.

 

[Yagenta13]

I probably won't spend the money to do much to change the bike and most of these ideas require skills working on a bike I just don't have- yet.

It sounds like adding power is much easier than making the bike more "efficient". I've been curious about what one might do though so I enjoy reading what people say who actually know these things in more detail.

I tried looking up links to this type of topic and I couldn't find much. Power rules I guess!

 

[flacoman]

Two things : A little taller tires will make the gear a bit longer
The twist grip works both ways !

 

[dwendt44]

Taller tire or next oversize tire if you have room for it (wider).
Synthetic oil might help a small amount.
Run tire pressures a hair higher.
Reduce weight (no unnecessary junk).
Think wind resistence.
Highway boards, oversize windshield etc. take power and gas to push them through the air.
Most bikes have a 'sweet spot' where it gets better mileage than at other speeds.
55-60 is usually it.

My 2¢

 

[BigCahuna]

My experience with trying to "Improve" what the factory has done, usually causes more problems and added expense. Rarely you will gain more mileage over box stock, buy messing with power commanders or other such devices. And when you add up the cost, there goes any saving you would have seen. If it ain't broke don't fix it.And keep your oil clean. there's such a small number of people that actually keep their bikes on the road for 100k miles, let alone 300k.,,

 

[dsmith41]

Originally Posted By: BigCahuna
My experience with trying to "Improve" what the factory has done, usually causes more problems and added expense.

If it ain't broke don't fix it.And keep your oil clean. there's such a small number of people that actually keep their bikes on the road for 100k miles, let alone 300k.,,


Yep. Spot on.