mods for better mpg

[michaelwoodcock]

http://www.factorypro.com/products/F...u_hi_disp.html
2-4 percent with needle jets. Not sure how they do it, but worth a try I believe
if you have CV carbs (verses slide carbs) you can shim the slide spring to make it open a little more slowly. Dual groudning strap spark plugs work well on certain engines by increasing turbulence when the air fuel ratio enters the chamber, and decrease efficiency on others by creating an obstacle for air during scavenging.

You can Key the spark plugs for a 2-4 percent gain if you get a proper kit

reducing the highspeed jet one size should help if you get hot air.

[CA ExhaustCoatings]

"if it is carbed, be sure to tune it to run stoichiometric (14.5 to 1) on hot air! "

stoich is the worst air/fuel ratio for mpg, u need to go leaner at cruise rpms.
stoich is an epa lie so the cats will work and nox is low. the epa makes every vehicle waste at least 10 mpg at hwy speeds with their 14.7:1. running leaner 15 to 16:1 will actually lower nox and increase hwy mpg. going leaner still is possible with proper engine and ignition design, but the epa has their head u know were.

[michaelwoodcock]

lol
well just thought you should re-jet if you're going to change the air/fuel mixture even a tiny bit. You should re-jet/tune for even the slightest mods. (air filter, exhaust, probably cams, pistons, etc.)

What about high velocity intake ports to increase low end torque? you know, take the cylinder head and reduce the width of the intake port. You can also do it to the exhaust port, but it requires skillful welding.

To do it on the intake port, you only need a dremel, some tips, and some JB weld.

[michaelwoodcock]

also, I think you've mentioned heating up the fuel, although I am not sure, and I didn't want to dig through the posts fo confirm. But, that might help a bit! Anything that would increase volatility of the fuel will probably give you a slight increase. Less than on a fuel injected engine, because the fuel is introduced with a longer length / volume before it reaches the combustion chamber, but, it should still make a difference. What do your intakes look like? Maybe some custom mandrel bent intakes, you could put on longer tubes to increase torque, and maybe even heat them up with engine coolant if you wanted to. Kindof like a water to air cooler, except a water to air heater disc brakes front and back? I am not sure about the valk, but, sportbikes have a spring type thing that pushes the brake pads against the disc. Creates a little bit of friction and heat. You may get some funny noises when you take them out, but it's all good. Just don't take any vital parts otu and you're good

[alvaro84]

Hi! I'm new here, trying to do my best with a motorcycle... one of the mods I'm interested is a tool like the ScanGauge the drivers use... is there anything like that for motorcycles? My bike (Teresa) is a 2004 (single spark) BMW F650CS, with a fuel injected, 652cc single cylinder engine. If anything can make things easier, having only one cylinder surely does. If I had a younger 'twin' sister, I'd have a factory on-board FE monitoring unit, but is there an option for a bike that doesn't have it by deafault?

And about the behavior some of you mentioned here - yes, they usually tend to answer with the phrase 'ride it like you stole it'; but at least at f650.com I found an older guy who got similar FE on an F650CS and he's been using his bike for almost 200k miles. He obviously rides very much and transports the craziest things on his bike, but his basics are NOT to ride the motorcycle with IC engine for just a few miles, walk or bycicle instead. I like it very much and it may contribute to the longevity of the motorcycle too

OK, I'm off to find a topic about hypermiling techniques applied to motorcycles; I found 'neutral' (held clutch, neutral is too far from 5th...) coasting ability at highway speeds to be a letdown (I'm not too surprised, a bike is light and its drag coefficient could be vastly improved... a windshield mod could probably help a bit, but I don't know anything specific... yet), I think continuous P&G would not be that good...

[theholycow]

AFAIK there are no standards like OBDII that are required on motorcycles. Your only option may be the same hacks that people with pre-OBDII cars have to do.

Unfortunately, most of those hacks may be too large and unwieldy for a motorcycle.

You mentioned a newer model having a factory system that would work. Could you get that system from a junked newer bike (or buy it from the pats department at your dealer) and retrofit it to your older model?

[alvaro84]

Originally Posted by theholycow

You mentioned a newer model having a factory system that would work. Could you get that system from a junked newer bike (or buy it from the pats department at your dealer) and retrofit it to your older model?

I'm afraid they're too different, I don't think the twin 800s' onboard computer could be fit on a 650 single. The first F650s are from 1993 or so, with the same Rotax engine, just they were carbed back then and they got FI at ~2000, with the introduction of the GS. The new F800s have been introduced in maybe 2006, based on a very different engine (a 800cc parallel twin) and pretty much everything else is different, I don't see why they wouldn't change the electronics to be totally incomatible

But even if I can't get instant FE data I'll continue my experiments. For now it seems that coasting is much more useful at city speeds, I could sustain the legal 50km/h along a pretty lengthy downhill. Also helps on the back roads if I spot the next village early enough to coast in - she can glide much longer under 60km/h (~37mph) than those miserable 11 second 85->70 (53->44) coasts downhill...
DFCO is useful too, if I have to lose speed and don't have to brake too rapidly. A 650cc single has pretty strong engine brake, in 1st gear it can make the rear tire slip.
EOC/CODFISH can be used very limited though, mainly when I know a stop light or I'm getting home/to work and am about to stop. If I start to coast with the engine off it's PITA to restart it and do a correct rev-match at a total random speed. I have to 'follow' the speed with the gear switch, or I'll wear the clutch much more than necessary, I'm afraid

Tires are overinflated now too. TTT it was not my idea, I got her back like this after the 30k service, and I rode a few hundred kms without the smallest problem before I checked the pressure
Factory values by BMW are 220/250kPa front/rear; Metzeler says 290 max (I have a set of Z6s); and my tires have been @300kPa (44 PSI) since the end of April. Maybe a bit too much, but I haven't experienced any problem. I used to keep them strictly at the factory values before the service. Maybe I should still deflate at least the front one a bit...

[theholycow]

I'd be wary of some of the common car techniques used on a motorcycle. I would surely be afraid to EOC and bump start, and increased tire pressure may be scary too.

The way some simple factory fuel economy displays on pre-OBDII cars (and presumably on motorcycles) work is by directly measuring the duty cycle of the fuel injectors and comparing it to speed. Systems like that should be able to be retrofitted to most fuel-injected vehicles.

There is a link in my sig for a DIY fuel rate meter; that one would work on your bike, but you may not be able to buy the meter easily, it's kinda large for using on a motorcycle, and its usefulness is somewhat limited (good for relative fuel rate readings but not fuel economy reading, and good for telling you when DFCO is working). In that post, there are links to threads about DIY fuel economy displays. I don't think any of them would work as easily for you, but you may be able to learn and get ideas.

[alvaro84]

Thanks, I'll wade through your signature (I've already had a few looks ).

I'd be reluctant to use bump starts, just the thought makes me feel pain around the clutch and the whole drivetrain... plus I really don't know what would happen, I'd may even hit the ground. I have no real experience with it. I bump started our other bike once (an even lighter Hyosung GV250), at a very low speed, but that was only an emergency start because of a dead battery. I'm not planning on making it a BAU activity.

[mikehallbackhoe]

I have tried eoc on my valk on steep downhill runs, but found it difficult to hold in the clutch very long ( carpal tunnel) don't think it was worth the effort