fuel capacity (was k&n filter question...)

[JWF]

Back in '78 I took a hammer and hacksaw to my SR500's airbox, clamped on an aftermarket filter which shall remain nameless (K&N) and a White Brothers (RIP) pipe. Rejetting details are lost in the fog, but the result was better throttle response from idle on up (looked and sounded better too). What is it about the KLR's design that it would not run better with maximized airflow, assuming the necessary compensations? Posted by: "nhjim10" jaltonnh@... nhjim10 Sun Feb 20, 2011 9:54 am (PST)

>. . . the airbox elimination thought is now gone. re: the design of >the stock airboxes, while some bikes are designed with maximum airflow >in mind, the KLR isn't one of them... >Jim

[Jim Fortner]

This http://langly.smugmug.com/Motorcycles/KLR/DSCN0492/18144094_fae54-M.jpgold IMS equipped KLR will go a little over 400 miles between fill ups of 8 gallons. The rider is usually more than ready for a stop by then. Jim

On Sun, Feb 20, 2011 at 5:31 PM, nhjim10 wrote: > > > Its not so much that I *need* the extra capacity, but I *want* it. For one > thing, with this bike I've fought mileage issues ever since new. If I'm > doing mild commuter riding and am very careful, I can barely squeak 220 > miles out of a tank. On the highway, it drops to 160-170. That 220 miles was > riding like Grandpa with speeds between 40-50. Highway mileage is whether > minimal or loaded, and a 16t sprocket. I've adjusted the carb, and the plug > has always looked great (original plug at 18k miles), no changes. I did the > t-mod, drill & needle shim at around 12k miles, still no changes (not that > those things would really affect mileage). All mileages are counted from > full until I have to switch to reserve. > > I'm hoping the poor ring sealing and oil consumption had a little to do > with it, and I may see a bit better with the 685 kit. But the extra capacity > is so I don't have to stop for fuel every 160 miles on the highway. Ideally > I would love to at least double that distance, using a combination of > improved mileage (crossing fingers) and extra capacity. When I'm trying to > rack up the miles on the highway every fuel stop consumes time. While a fuel > stop should take 5 minutes, in reality when combined with human nature, it > can easily turn into 10-15 minutes. Factor in slowing down for the exit, > hitting a stoplight or two each direction, removing the helmet, fueling up, > taking time to grab a snack or drink *while I'm there anyway*, hitting a > couple stoplights on the way back onto the highway, and getting back up to > speed. For a 1000 mile day at 160 miles a tank, I'm looking at a minimum of > 6 fuel stops. At 10 minutes each I'm at an extra hour. If I can cut those > stops in half I can save an easy 30 minutes throughout the day. > > That doesn't matter when I'm just doing a relaxing day ride around New > England, but on the long trips it adds up. In fact, when I attempted my > first Iron Butt saddlesore ride I missed doing it by minutes. I was at 987 > miles at the 24 hour mark. Other factors affected it, such as having to work > a full 8 hour shift before I left right from work, and having a chain > grenade in Virginia, forcing a couple hours of downtime while I made repairs > and located a chain. > > I think I've decided to limit added fuel capacity to what I can easily do, > such as a rear tank and/or IMS tank. As soon as hours pick up at work and I > get rid of a payment I'm currently stuck with (done in July) I'm most likely > going to pick up either a V-Strom 1000 or ST1300 for the long rides. I like > the minimal bike of the Vee, but I like the shaft drive of the ST (I'm an ex > ST1100 owner). Then I can add fuel capacity to either of those and really > stretch out my stops. > > Jim > > --- In DSN_KLR650@yahoogroups.com, "fasteddiecopeman" > wrote: > > > > I can generally go around 500 kms (300 miles) to empty, and I 'modded' my > fuel petcock so that I have about 160 kms (100 miles) once I go on reserve. > The longest run I've done between gas station AVAILABILITY is the Dempster > Highway, where gas is available at the start, mid-point, and end, so you > need a range of about 360 to 375 kms. I believe I went onto reserve prior to > the stations, but NOT for many kms! > > Do you REALLY need MORE gas...? > > Cheers, > > Ed > > > > > [Non-text portions of this message have been removed]

[Ian]

The KLR airbox was likely designed for water resistance and possibly mid-range torque (3-5krpm). Some newer cars and bikes are running variable length intake runners to address intake velocity requirements. What is needed to maximize low-end and midrange torque is not the same as what's needed for top end horsepower. Until you get real hi-tech you're giving up something somewhere to get something somewhere else. Being an oversquare design (bore larger than stroke) with four valves the KLR is already revvy and flows well in stock form compared to something like a 2 valve SR or XT 500, and is light-years ahead of the old sidevalve singles which were long stroke engines and had gobs of torque right off idle but no top end. Many people have tried to wring more power out of the KLR motor with intake and exhaust mods, head work, rejetting, etc. and the general consensus is your money's better spent on suspension upgrades. You just lose a lot of mpg to gain a very few bhp. The one exception to that seems to be the Schnitz 685 kit which is a much better piston than stock and makes a smoother and better KLR engine. A KLR engine with its heavy and antiquated chain driven balancer system is never going to be a fire snorting KTM or Rotax competition single. It's more like an over-grown lawnmower engine. That's just the reality of the design. If you want more power you might want to look at a DL650 or Versys, or go even bigger. Just turned over 40k miles on my KLR this weekend. Had to break in that new chain - rain or no rain I got 52.6 mpg last fill-up (3.8 gallons in 200 miles). Mine is down on power compared to new I'm sure but it will still roll along at an indicated 80mph and hold it on most hills. Not much passing power left at that speed, but you ride the bike like it wants to run, you know? I didn't know that 25 years ago about my XT500, thought it could run at 75mph all day on the freeway and still chug up hills at 1200rpm. In retrospect I was asking a bit much from it. And it let me know - failed camchain at 13k miles led to trashed top end. That camchain was not much bigger than the one on my XL175. Glad the KLR uses a two-row chain.

--- In DSN_KLR650@yahoogroups.com, "JWF" wrote: > > Back in '78 I took a hammer and hacksaw to my SR500's airbox, clamped on an aftermarket filter which shall remain nameless (K&N) and a White Brothers (RIP) pipe. Rejetting details are lost in the fog, but the result was better throttle response from idle on up (looked and sounded better too). What is it about the KLR's design that it would not run better with maximized airflow, assuming the necessary compensations? > > Posted by: "nhjim10" jaltonnh@... nhjim10 > Sun Feb 20, 2011 9:54 am (PST) > >. . . the airbox elimination thought is now gone. re: the design of >the stock airboxes, while some bikes are designed with maximum airflow >in mind, the KLR isn't one of them... > >Jim >

[cycletip]

Well said Ian. Also had one of those monster Yamaha's in the TT version. Bucked me off and broke my neck. More bike than I could handle at the time but the torque was outstanding! Monty

--- In DSN_KLR650@yahoogroups.com, "Ian" wrote: > > The KLR airbox was likely designed for water resistance and possibly mid-range torque (3-5krpm). Some newer cars and bikes are running variable length intake runners to address intake velocity requirements. What is needed to maximize low-end and midrange torque is not the same as what's needed for top end horsepower. Until you get real hi-tech you're giving up something somewhere to get something somewhere else. > Just turned over 40k miles on my KLR this weekend. Had to break in that new chain - rain or no rain I got 52.6 mpg last fill-up (3.8 gallons in 200 miles). Mine is down on power compared to new I'm sure but it will still roll along at an indicated 80mph and hold it on most hills. Not much passing power left at that speed, but you ride the bike like it wants to run, you know? I didn't know that 25 years ago about my XT500, thought it could run at 75mph all day on the freeway and still chug up hills at 1200rpm. In retrospect I was asking a bit much from it. And it let me know - failed camchain at 13k miles led to trashed top end. That camchain was not much bigger than the one on my XL175. Glad the KLR uses a two-row chain. > > --- In DSN_KLR650@yahoogroups.com, "JWF" wrote: > > > > Back in '78 I took a hammer and hacksaw to my SR500's airbox, clamped on an aftermarket filter which shall remain nameless (K&N) and a White Brothers (RIP) pipe. Rejetting details are lost in the fog, but the result was better throttle response from idle on up (looked and sounded better too). What is it about the KLR's design that it would not run better with maximized airflow, assuming the necessary compensations? > > > > Posted by: "nhjim10" jaltonnh@ nhjim10 > > Sun Feb 20, 2011 9:54 am (PST) > > >. . . the airbox elimination thought is now gone. re: the design of >the stock airboxes, while some bikes are designed with maximum airflow >in mind, the KLR isn't one of them... > > >Jim > > >