[Ptm]

Hello,
I'm getting bad fuel economy on my '06 ninja 500R, even with a economy riding style shifting in low rpms. It is approaching my 3 liter 6cyl BMW 5 series in fuel economy..

I changed the plugs to no effect.
It definitely needs a valve adjustment, coming soon.
I am about to sync the carbs as well.
Chain is lubed, tires are at pressure, etc.

Is there anything else I'm forgetting or missed in search? Greatly appreciate the help, thank you.

 

[FlipFlop]

Low RPM's tends to lug the motor it is much happier above 5k, on mine anyway.

 

[fog]

check for stuck or leaking carb float valve, should be stumbling at low speeds too

FOG

 

[yorkie]

yeah sounds like it's over fuelling some where or just way out of tune. the average mileage per tank full (for my riding) is around 180miles. probably more if cruising but with our roads that doesn't happen very often.
also the the tank is never empty when filling so perhaps 3.5 gallons (imperial) so 180 divided by 3.5 = 51mpg.

 

[Ptm]

The bike runs and idles quite well once at temp, and I'll ride it all over the state but it struggles with cold starting and won't run at idle until warm. I'm really hoping valve adjustment fixes that, I'll bet it has missed one at 15,000mi.

Yorkie, is that 180 mi range not including reserve? I did not realize the main tank is only 3.5 without the reserve so my gas calculation might be way off. I think I've hit ~170 before switching to reserve which would be close to yours. I haven't pushed it that far in a long time and I will need to test again.

 

[bpe]

Main tank is more like 3.7 gallons. Yorkies' gallons are not the same as US gallons. Your definitely getting better than 30 MPG's. I usually get about 184-188 miles before reserve in the winter, and about 200 - 206 in the summer.

 

[yorkie]

Yorkie, is that 180 mi range not including reserve? I did not realize the main tank is only 3.5 without the reserve

yes correct, I never calculate the fuel reserve because it's a reserve (in absence of a fuel gauge) and therefore only used if absolutely needed. it's complicated to asses and make comparisons, because not only is @bpe correct in our gallons are different to your gallons but our fuel is sold in litres (thanks Europe).
but 16ltrs = 3.5imp galls usually get me around 180/190 miles before I need to fill up again. fair enough sometimes it's more sometimes less. but that is just an average.

 

[Clive]

Agree with above. Sometimes I've only had 35 mpg due to me "razzing" it... on average go for 55 to 60 to the gallon. Yorkie is right, I aways exclude the reserve - about 1 gallon by the way. Fuel up, reset the odometer, and I do 120 to 150 miles, then start looking for a petrol station. I've also noticed that some of the younger guys on here are a bit inexperienced with cold starting/choke procedures etec, due to these bikes being carbs etc... I never consider an engine of any carb bike to be running rough when cold, because they all do! It's only after several miles, with a warm engine, you can then listen and consider rough idling etc, in which case it is definately the pilot

 

[e10_muppet]

fwiw I usually get around 65mpg (UK gallons) with a route split about 50:50 across motorway and city. Although lots of the motorway work is still filtering at about 30-40mph. If the valve clearance doesn't result in a change try a full carb overhaul.

Silly obvious question - but if you let it sit and idle for a while does the air fill with a rich fuel smell? I only ask because when I screwed up my first carb overhaul this was the main tell, that and the fuel pissing out of the carb inlets.

 

[Custom Carb Service]

If and when you need a pro carb service/clean, contact me. I'm sure you've seen pics and read results posted right here on EX.

 

[Ex500D-Can]

If you have an android device, get this:
"FillUp_2.1.1.apk" Excellent for keeping track of mpg/kml etc. You can create databases for all your vehicles...been using it for years

My average is apparently 18kml (it has graphs too) which equates to 42.33mpgUS or 50.84mpgIMP

also useful app, to corelate kml;mpg or inch;cm, etc. etc. etc,; Equate "com.llamacorp.equate_12.apk" I think both available at Fdroid... Carbed bikes all seem to get similar mileage across a wide range of cc's. I can get 22kml on a steady highway trip but all year,40km trips going from bike to bike, pretty near 18-20kml.

 

[Clive]

fwiw I usually get around 65mpg (UK gallons) with a route split about 50:50 across motorway and city. Although lots of the motorway work is still filtering at about 30-40mph. If the valve clearance doesn't result in a change try a full carb overhaul.

Silly obvious question - but if you let it sit and idle for a while does the air fill with a rich fuel smell? I only ask because when I screwed up my first carb overhaul this was the main tell, that and the fuel pissing out of the carb inlets.

Nope. No carb motorcycle - including ours - should fill the air with a rich fuel odour! In fact I've found the carbs on these bikes very good, never touched mine in over 9 years! A dash of Redex on every fill-up keeps the carbs and engine running sweet. I do a similar commute. High speed dash along the A96, final couple of miles is slow speed filtering into the city centre (Inverness). Temp needle rises to the middle and that's all good with me, as these engines run cold all year round up here, so a bit of stop start does the engine good in my opinion. Fuel p*ssing out of the carb inlets? Mmmm, did you reassemble the fuel tap with the VAC tap? That is, the correct way? A lot of folk foresake the vac, for a standard tap, big mistake in my opinion. Not that difficult to master, just fiddly to reasemble and screw up.

 

[yorkie]

yes I agree with Clive not normal at all although if you leave it running from cold in a enclosed space you may get a touch carbon monoxide poisoning, but not heavy fuel smell.
as for petcocks each to their own I prefer manual ones, while vac operated ones are usually reliable they can fail not often but when one does fail and you got lazy and forgot to turn it off while leaving the bike parked on the side stand and it leaks fuel from the left (lower) carb and fills the bore with fuel, you are reminded to make sure it's off when parked,
if your going to do that anyway might as well be a manual one, also makes filling the carbs faster too if they are run dry.

 

[Clive]

yes I agree with Clive not normal at all although if you leave it running from cold in a enclosed space you may get a touch carbon monoxide poisoning, but not heavy fuel smell.
as for petcocks each to their own I prefer manual ones, while vac operated ones are usually reliable they can fail not often but when one does fail and you got lazy and forgot to turn it off while leaving the bike parked on the side stand and it leaks fuel from the left (lower) carb and fills the bore with fuel, you are reminded to make sure it's off when parked,
if your going to do that anyway might as well be a manual one, also makes filling the carbs faster too if they are run dry.

On a seperate matter Yorkie, I need to think about some heat resistant black paint for the cam cover. It has to be a thin gloss paint - I don't like those heavy, thick paints as they always leave brush marks. I have some very good light brushes and I can apply the paint very lightly, so no obvious brush marks. Can you recommend a tin please? In the past I've always used the Halfords range of gloss tin paints, they are excellent when applied with a fine brush, and last longer than rattle can applications. I'll have to take the tank off this Spring to get at the sparklers and do the tappets, so might as well do a proper job and touch up all necessary frame and engine parts. My swing arm has really suffered this year due to being outside on the drive, but when (!) I get a nice sunny afternoon (!) I don't mind getting out and doing these jobs. I suspect this will be the last major service for my bike, as the frame structure is now on the MOT advisory. Thanks.

 

[[email protected]]

"as the frame structure is now on the MOT advisory"

What the heck does that mean?

 

[yorkie]

What the heck does that mean?

here in the UK every motor vehicle over 3 years old has to pass a rigorous mechanical inspection by a government approved tester. it's called an MOT test (ministry of transport) if it passes the test you get a certificate that last one year when the process is repeated every year, if the tester finds a fault that is deemed not dangerous but will require attention before the next MOT test he issues an advisory notice to the certificate, you are supposed to have the fault rectified before the next MOT test, or it could result in a failure of the test. of course if this happens you vehicle is then off the road until the fault is rectified and it can then pass the test.

Clive. not sure what to suggest for the paint I always use HI-TEC engine paint in a rattle can it's heat resistant oil and fuel proof and doesn't peel if you spill brake fluid on it (guess how I found that out) for the frame it's a scrub with a wire brush rust cure and then a top coat of Hammerite smooth.

 

[e10_muppet]

Nope. No carb motorcycle - including ours - should fill the air with a rich fuel odour!

Sorry I was probably writing in quite an indirect way. I meant - If fuel is pissing out of the bike at a fair clip then you'll likely smell it.

In my case that was from basically not adjusting some brand new floats. So nothing to do with the tap, it was literally just fuel overflowing the bowls and then leaking out of the inlet.

 

[Clive]

here in the UK every motor vehicle over 3 years old has to pass a rigorous mechanical inspection by a government approved tester. it's called an MOT test (ministry of transport) if it passes the test you get a certificate that last one year when the process is repeated every year, if the tester finds a fault that is deemed not dangerous but will require attention before the next MOT test he issues an advisory notice to the certificate, you are supposed to have the fault rectified before the next MOT test, or it could result in a failure of the test. of course if this happens you vehicle is then off the road until the fault is rectified and it can then pass the test.

Clive. not sure what to suggest for the paint I always use HI-TEC engine paint in a rattle can it's heat resistant oil and fuel proof and doesn't peel if you spill brake fluid on it (guess how I found that out) for the frame it's a scrub with a wire brush rust cure and then a top coat of Hammerite smooth.

Yeah, that's why I was asking, found out the hard way after spraying the frame with Halfords rattle can, spilt some petrol a few weeks later and oh dear...... you can guess the rest! I'll have a look at your suggestion first. Thanks.

 

[Ptm]

I got 146mi until main tank went dry then a loss of power. I was working Uber eats with frequent stops and many, many spirited pulls to 40mph followed by high gear cruising on country roads and minimal street traffic. I was having a grand time.

Just over 4 US gallons to refill to just under the brim of the tank. 146/4= 36mpg. I definitely could have been lighter on the throttle..🤷‍♀️share your thoughts.

I'm a 34yo youngin who definitely does not know jack about carbs. This is my first carbed engine that didn't cut grass. All my bikes and cars have been FI. However this bike has a perfect idle once warm and sure feels like it makes good power. That's good enough for me to not go messing with it past a valve adjustment, sync, idle, and a compression test yet. If a compression test comes back bad then I'll probably be handing these carbs over.

I've got to say I have been impressed by this bike. I've seen some very high mileage examples out there in the wild, and I think this one has a good shot of getting there

 

[Clive]

I got 146mi until main tank went dry then a loss of power. I was working Uber eats with frequent stops and many, many spirited pulls to 40mph followed by high gear cruising on country roads and minimal street traffic. I was having a grand time.

Just over 4 US gallons to refill to just under the brim of the tank. 146/4= 36mpg. I definitely could have been lighter on the throttle..🤷‍♀️share your thoughts.

I'm a 34yo youngin who definitely does not know jack about carbs. This is my first carbed engine that didn't cut grass. All my bikes and cars have been FI. However this bike has a perfect idle once warm and sure feels like it makes good power. That's good enough for me to not go messing with it past a valve adjustment, sync, idle, and a compression test yet. If a compression test comes back bad then I'll probably be handing these carbs over.

I've got to say I have been impressed by this bike. I've seen some very high mileage examples out there in the wild, and I think this one has a good shot of getting there

Nice, thanks. Yeah, just to add - these engines are true GPZ's, with very good carbs to match IMO. Don't touch them! You're right too, once properly warmed up, the engines idle smoothly, a good sign your carbs are spot on! Also, once these engines are properly warmed up they run very smoothly for a paralle twin, almost as good as a 4 cylinder machine. I know some bikes have done in excess of 100,000 miles with minimal servicing, so at a bare minimum just plain old 10W40 mineral oil and filter. You'll see most guys on here have had a variety of bigger, more powerful machines, but for most of us, the little GPZ500 has always been a "keeper".