VRON Posted July 25, 2014 Share Posted July 25, 2014 I have a 2004 VFR800 that currently has 43,000 km (26,700 miles). Last season, I got on average between 280-320 km (174-198 miles) to a tank. I know what you might be thinking, and no, my riding style has not changed. This season, I am getting about 180-220 km (112-136 miles) to a tank. My chain is really sagging and well overdue for a replacement (can no longer extend), so my mechanic ordered a new chain and sprockets that will be installed next week. I am also going to get an oil change at the same time. He also has many other suggestions that could be the reason for my loss of mileage - new filters, new spark plugs, etc. Before I got and spend a bunch of money, I am hoping you guys can help me out:1.) Do you think my sagging chain could be the culprit? 2.) What else would you suggest I update/change on my bike?I bought my bike last summer with around 27,000 km an I am not sure what the previous owner had recently updated. New to Forum - A Little About Me: I have been a crotch rocket rider for about 10 years, mostly on Ninjas. I began to notice I had less and less interest in the track and a lot more interest in long hauls. I wanted a sport touring bike that still had some balls and decent handling, without the discomfort of a pure crotch rocket, and also a bike that I could take a passenger on. My research led me towards a VFR800 as it is one of the rare machines out there that is more sport than touring. Most so-called "Sport Touring" bikes are absolutely boring. I added full saddlebags and a large tailbag with a passenger backrest. In 2013, I rode from Canada to Ensenada, Mexico and back, covering about 11,000 km (6,800 miles) and 13 states/provinces in three countries with a passenger. And what did I learn? I should have my bought my VFR years ago! I love it! Link to comment Share on other sites More sharing options...
volleytron Posted July 25, 2014 Share Posted July 25, 2014 I'm in the same boat as you. My '03 vfr only gets about 125 miles to the tank, with mostly city driving. Still looking for a fix(if there is one). I'm starting to think it's the pressure regulator. I get a strong smell of raw gas out of the exhaust. Do you smell gas? Link to comment Share on other sites More sharing options...
VRON Posted July 25, 2014 Author Share Posted July 25, 2014 No gas smell that I can think of, but I will pay attention later on today to see if I notice. Link to comment Share on other sites More sharing options...
TNRabbit Posted July 25, 2014 Share Posted July 25, 2014 What temp does it run? If not the FPR.... someone recently posted bad fuel economy & it ended up being the MAP sensor vacuum line was unplugged.... Link to comment Share on other sites More sharing options...
Earthshake Posted July 25, 2014 Share Posted July 25, 2014 I think more than one member has noticed a significant reduction in range when the thermostat went bad. If it's stuck open, bike runs cool and never gets up to normal operating temp. As a result, ECU keeps sending additional fuel thinking motor is still warming up. Link to comment Share on other sites More sharing options...
Member Contributer dawson Posted July 25, 2014 Member Contributer Share Posted July 25, 2014 Check all the vacuum lines. One that's off or leaking will land you down in that mileage. They're a double hit; MAP and fuel pressure regulator will both get false readings and richen things up. Link to comment Share on other sites More sharing options...
Member Contributer RichVee4 Posted July 25, 2014 Member Contributer Share Posted July 25, 2014 Since you are talking about range and not MPG are you certain that you are starting with a full tank? Fuel gauge to the full mark? can be a little tricky to top off but try to fill to the bottom of the filler neck on the center stand? Link to comment Share on other sites More sharing options...
VRON Posted July 26, 2014 Author Share Posted July 26, 2014 Thank you everybody for your help. I am about to get off work so I will go for a boot and check the temperature. The mechanic thought that my temperature was reading fine. I am also sure to fill her to the brim, as well, mostly because I often go long hauls with many km/miles between gas stations.What is FPR and MAP sensor? What does ECU? How many vacuum lines are on a VFR?I am not as mechanically savvy as I would like to be, but eager to learn with your help. Link to comment Share on other sites More sharing options...
VRON Posted July 30, 2014 Author Share Posted July 30, 2014 Update: Bike is in the shop today getting a new chain and sprocket (definitely saggy and needs to be done). I am also getting an oil change.A mechanically savvy motorcycle buddy of mine suggested that I buy fuel injection cleaner, then run a full tank after the new chain/sprockets and see where the mileage is at, before doing more changes. If this isn't enough to get my mileage back, I will look into spark plugs and vacuum lines.Thank you all you for your help. Link to comment Share on other sites More sharing options...
Member Contributer PorradaVFR Posted July 30, 2014 Member Contributer Share Posted July 30, 2014 I'm one of the folks with mileage issues, albeit not as bad as yours. I found it was running rich and short story long I ended up replacing O2 sensors and the entire injector assembly - the bike no longer runs rich and the throttle response is night/day smoother...but my mileage is almost entirely unchanged. Given the money and time spent I'm accepting that Dusty is just a thirsty girl. At ~31-32 mpg I'll live. Link to comment Share on other sites More sharing options...
Baileyrock Posted August 2, 2014 Share Posted August 2, 2014 I think more than one member has noticed a significant reduction in range when the thermostat went bad. If it's stuck open, bike runs cool and never gets up to normal operating temp. As a result, ECU keeps sending additional fuel thinking motor is still warming up. Agreed, T-stats are a Known problem on 6th gens and a faulty one will cause the bike to run rich(actually think they run better this way, but mileage suffers). Temp reading won't be crazy off just cooler then a properly working stat. Link to comment Share on other sites More sharing options...
VRON Posted August 7, 2014 Author Share Posted August 7, 2014 Update: I have a new chain and sprockets, also a recent oil change - and some success! I also filled the tank to the brim and added fuel injection cleaner. With a mix of city/highway riding, I got 270 km (168 miles) to my last tank, which is pretty decent and a huge improvement from the 190 km (118 miles) I was getting before those changes. I think my thermostat is okay because the operating temperatures seem normal. I may still change the spark plugs and air filter as well, as I think I am due. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted August 7, 2014 Member Contributer Share Posted August 7, 2014 +1 do the plugs . Link to comment Share on other sites More sharing options...
VRON Posted August 8, 2014 Author Share Posted August 8, 2014 Update: I did a bunch of work on the bike last night with a mechanically-savvy buddy:-Replaced the spark plugs. The front ones were easy, but the back ones were tough. I was surprised how much the plugs cost. I called around a bit and the best price I found was $19 a plug. One advice I received from my buddy with the spark plugs is once they are snug, just give them an extra 1/4 turn, but not to over tighten.-Examined chain as recently installed new chain and sprockets, which really helped get my mileage back. I am quite confident now the main culprit for mileage loss in my case was needing a new chain and sprockets. It hasn't sagged too badly since the new install so I didn't adjust it. Lubed her up, of course.-Took tank off and examined air filter. Myself or the previous owner apparently drove through a Caesar salad at one point or another (check the photo), as the air box was filled with croutons. I cleaned it with an air compressor, but will have to order a new one. I have been reading a lot of conflicting information on what kind of filter to buy, but thinking K&N because it is cleanable. My buddy who was helping me fixes a lot of bikes and he uses K&N always. He said the filter should be good for a bit as the air compressor did a good job, but that I should replace it.-Unrelated: I decided to bleed the clutch and brakes while I was at it. Mine were very dirty, almost black in color.I hope to do a bit of a road trip this weekend, so I'll let you guys know how the mileage is. It has already improve drastically. The work we did last night has definitely made my bike feel way more powerful and smoother.Photos Attached to Help Someone Else Out Doing Similar Work: -Location of one of the rear spark plugs-Photo of old spark plug-Location of air filter box-Crouton-covered filterTools Suggested:-Air Compressor to clean areas, including air filter if not replacing. The reason I didn't replace it right away, is I thought maybe the previous owner had a K&N filter that I could clean. I figured I should check first before ordering a new filter.-Lemon Pledge - always recommend this for any clean up on anything bike related. It is great for getting rid of bugs.-Rubber Tube for bleeding-Wrenches and other basic tools-One long screwdriver to get to tough areas-Long magnetic stick to find lost screws and guide out the old plugs-Lots of ragsThanks again for everybody's input. Link to comment Share on other sites More sharing options...
Guest Posted August 8, 2014 Share Posted August 8, 2014 Are those really croutons !?!?! Looks like someone has/had a rodent problem. Link to comment Share on other sites More sharing options...
VRON Posted August 8, 2014 Author Share Posted August 8, 2014 hahaha yup! Myself or the previous owner either rode through a Caesar salad or had some rodents living in the bike during the winter. Link to comment Share on other sites More sharing options...
smoothsailin Posted August 8, 2014 Share Posted August 8, 2014 LOL. I've Never heard of a rodent stock-piling croutons before. The critter must not have been very hungry at the time since most of them appear to be untouched. Also, is that a K&N, or an oiled-fabric type air filter from another aftermarket company? If so, I'd just clean, oil and re-use in lieu of replacing the filter element. I have had mice to pack just about every available crevice they could find in my shed (including inside the fingers of my gloves and in the space between the banks of cylinders of my ST1100) with straw, sunflower seeds, newspaper shavings, etc. Didn't think I'd ever get all the sunflower seed shells out of my gloves (very uncomfortable). Although the image isn't very clear, the spark plug appears to be awfully black-which suggests your engine has been running rich. The spark plug gap also appears to be excessive/too wide-which could also affect drivability and fuel economy. I certainly would balk at paying $19 for replacement plugs and would be surprised if you couldn't find better prices for replacments (including free shipping) on E-bay or Amazon.com. According to my records when I last replaced the plugs in my 5th-gen I paid ~ $7.69 each for them at a local NAPA store-which at the time I thought was still rather expensive for spark plugs. I can't get over how low the miles-per-tank and average mpg results reported by a significant number of owners (especially those riding 6th-gens) are compared to mine. I typically manage to go 220-250 miles per-tank and calculate tank averages in the 48-53 mpg range with my '98 5th-gen unless I've been consistently heavy on the throttle. I can't recall ever computing less than 40 mpg-even after I'd made several runs through the Tail of the Dragon in 2nd gear! Link to comment Share on other sites More sharing options...
marriedman Posted August 8, 2014 Share Posted August 8, 2014 The croutons are the best! I have never seen that before, lol! When I first bought my 6th gen, I only got 130 to a tank. Now I don't know if it was the shitty winter blend still in the stations, but if I go up in octane I could get almost 200. As for the temp being a culprit, if the thermostat was stuck, the VTEC wouldn't kick in either. So that would be an easy way to diagnose the thermostat. Link to comment Share on other sites More sharing options...
smoothsailin Posted August 8, 2014 Share Posted August 8, 2014 Forgot to mention...I recommend caution when using compressed air to clean engine air or oil filter elements. Conceivably, the use of high pressure air could damage the filter media and allow abrasive particles to get through to the engine afterward. I prefer to use a high-volume/low-pressure air source like my leaf blower or shop vacuum for blowing or vacuuming filters that I intend to re-use. Compressed air can also be used so long as you're careful not to bring the nozzle to too close to the filter media. I also learned a hard lesson after foolishly electing to use compressed air to assist with evacuating the last bit of liquid after flushing & draining the cooling system in one of my vehicles some years back. Afterward I end up having to purchase & replace a previously water-tight heater core. I'll never forget what a p.i.t.a. THAT job was! Had to remove and disassemble the entire dash assembly to gain access to the core. Lesson learned co Link to comment Share on other sites More sharing options...
VRON Posted August 15, 2014 Author Share Posted August 15, 2014 Thanks for the info, everybody! I am riding her down the Oregon Coast and back up through the Kootenays of British Columbia. Mileage has improved with the modifications I did last week. Link to comment Share on other sites More sharing options...
raoufhakam Posted August 15, 2014 Share Posted August 15, 2014 i'm not sure if you were doing it wrong, but I found replacing spark plugs in my 5th gen VFR by far the easiest from all the bikes I've owned or worked on. try replacing sparkplugs in a modern inline-4 sportbike, have to pretty much tear the whole bike apart heck, even the Suzuki V-Strom / SV650 with a V-twin engine was way harder than the vfr $19/plug for iridium is not too bad. for some reason when I replaced the plugs in mine last month, the local store I bought them from had the pricing on the NGK iridium less than the normal NGK by $3-4/ plug Link to comment Share on other sites More sharing options...
signal Posted August 15, 2014 Share Posted August 15, 2014 PorradaVFR, What do you mean "entire fuel injector assembly"? Do you mean all four injectors were replaced? What could possibly warrant something like that? At best I would think you would need them cleaned. Or are you talking about even more being replaced? (throttle body, fuel rails, etc) Link to comment Share on other sites More sharing options...
TNRabbit Posted August 16, 2014 Share Posted August 16, 2014 Someone recently posted about dumping an entire bottle of Seafoam (WalMart) into a full tank of gas & realizing a fuel economy increase of @ 10 mpg.....might have been on either of the VFR forums. Worth a try....I just tried it tonight. Link to comment Share on other sites More sharing options...
raoufhakam Posted August 16, 2014 Share Posted August 16, 2014 Someone recently posted about dumping an entire bottle of Seafoam (WalMart) into a full tank of gas & realizing a fuel economy increase of @ 10 mpg.....might have been on either of the VFR forums. Worth a try....I just tried it tonight.Keep us updated :D Link to comment Share on other sites More sharing options...
TNRabbit Posted August 16, 2014 Share Posted August 16, 2014 Someone recently posted about dumping an entire bottle of Seafoam (WalMart) into a full tank of gas & realizing a fuel economy increase of @ 10 mpg.....might have been on either of the VFR forums. Worth a try....I just tried it tonight.Keep us updated :D Will do~ Link to comment Share on other sites More sharing options...
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