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DOHC 10.5liters/100km
- Thread starter overpl
- Start date
Is your odometer accurate? Are you riding at high speeds (I know you are!)? Are your brakes in good order? Tires properly inflated?
I'm averaging 5.3L/100km but don't ride often over 110 kph. Mostly around 90 - 100 kph with throttle lock on.
I'm averaging 5.3L/100km but don't ride often over 110 kph. Mostly around 90 - 100 kph with throttle lock on.
well - As I've mentioned few times here - I havebad brakes - but they are extremely poor - so I don't think there is a relation here.
I ride in avg about 70-100kph so its not a hard ride:/
I'll set GPS next time when I'll ride and see if kph and trip distance are accurate - but I doubt they would lie that much:/
Tires - 1.8 front, 2.0 rear - so like in manual..
I ride in avg about 70-100kph so its not a hard ride:/
I'll set GPS next time when I'll ride and see if kph and trip distance are accurate - but I doubt they would lie that much:/
Tires - 1.8 front, 2.0 rear - so like in manual..
you can probably go a bit higher in tire pressure, the manual is for stock bikes back in the 80's. Tires have evolved, you should check the specs for the ones you have. I'm on 2.0 front, 2.5 rear and it's pretty nice.
very true. I would check:
- if your brakes are not sticking (try putting the bike on center stand and turn the wheels, should turn freely)
- clutch adjustment
- chain condition (check for hard, locked links)
- fuel leaks (around your carbs, petcock, tank area)
- air/fuel mixture - make sure your valves are in spec, your carbs are synced and well adjusted
- timing (see manual)
- compression (maybe your piston rings are worn, maybe you need a rebore)
- if your brakes are not sticking (try putting the bike on center stand and turn the wheels, should turn freely)
- clutch adjustment
- chain condition (check for hard, locked links)
- fuel leaks (around your carbs, petcock, tank area)
- air/fuel mixture - make sure your valves are in spec, your carbs are synced and well adjusted
- timing (see manual)
- compression (maybe your piston rings are worn, maybe you need a rebore)
that is my huge problem - my center stand is worn i think
Bike stays with 2 wheels on ground when its on central :///will do - but doubt it have major infuence on consumption
chain is in good shape
I believe I have damaged diaphragm in petcock, but I can't find proper one - i think previous owner changed the fuel tap - I have diaphragm looking like square+triangle, but in every repair kits I see square shaped ones. Still - it can be part of my problem I guess, but its not completely damaged so the leak isn't big I guess and goes directly to carbs - not outside.
sync of carbs doesn't influence on consumption
vales like I said - I did clearance right, and I believe float height is right in them - I did not check the fuel level though - only float height
My mechanic friend said that this is setted once in electric starters and there is no reason to re-do it - he is wrong?
I must do compression - but still I think it would rather do poor engine performance than actually bigger fuel consumption :/
More thoughts?;] I will though check all of this.
that is my huge problem - my center stand is worn i think
Then put a jack under it, or a crate, or a log, or your mom, or something.
If your clutch is not grabbing on well (slipping slightly) you'll have to open up the throttle further to get to the same speed. Maybe this bike just has more power than you think, but it's being wasted.
Ok that shouldnt be the issue then
Yes it does. If it's not running perfectly, it'll use more fuel. You will need to apply more throttle to get to the same speeds.
Depends on your model. Have a look in the manual - there's a section about it for a reason. And he is correct that the timing is set more or less in stone on these DOHC's, but if someone (a previous owner, perhaps) has been messing with it, it'll be off.
True, but same story again. Less performance = higher fuel consumption
More thoughts?;] I will though check all of this.
well, how are the plugs doing? running rich maybe?
good luck!
I will check those maybe 2day - thank you, I'll let ya know what I did.
Now I'm going to pickup my mom in case jack will not be enough
markjs
XS400 owner, bike lover
- if your brakes are not sticking (try putting the bike on center stand and turn the wheels, should turn freely) - breaks are fine (no they don't but wheel is moving freely)
- chain condition (check for hard, locked links) - good shape
- fuel leaks (around your carbs, petcock, tank area) - no fuel leaks
- air/fuel mixture - make sure your valves are in spec, your carbs are synced and well adjusted - everything is fine - but sparks are black so to rich mixture but carbs are limited in float almost to minimum :/
More ideas?;/
but wheel is moving freely)- chain condition (check for hard, locked links) - good shape
- fuel leaks (around your carbs, petcock, tank area) - no fuel leaks
- air/fuel mixture - make sure your valves are in spec, your carbs are synced and well adjusted - everything is fine - but sparks are black so to rich mixture but carbs are limited in float almost to minimum :/
More ideas?;/
Air filter? Jetting? Needle height? Lean the idle mixture (pilot) screws a bit. They effect cruising mixture as well as idle.
No, not idle speed. Idle mixture. If set too rich, this will effect idle and part throttle. And possibly explain your black spark plugs.
Ok, so I've decided to refresh this topic
1. After fixing choke - I mean I pushed out choke manualy - it seems to not fully close when closing with line - still about 3-5mm 'in' when I close the choke on bar.
2. After risin up the float height to about 22mm I think
3. New tires (about stock size)
- consumption is about 7 L / 100km in the city and about 5,8 L/100km at highway but with speed like 80-90kph on avg.
So its still kinda f.. up.:/ I checked the sync of carbs - they are almost perfect - also they are clean and as I told before jets are new.
I don't know how to set iddle mixture if its not the same as idle RPMs (??)
I don't know if I can raise float height any more - nevertheless I still have feeling that my XS is getting flood - mostly because when I drive at constant speed sth engine starts to choke a bit, and when I shifting down with throttle (I don't know how to name it in english) sometimes when I try to rise RPM with throttle at clutch it doesnt react at all (??:|).
So? suggestions?
1. After fixing choke - I mean I pushed out choke manualy - it seems to not fully close when closing with line - still about 3-5mm 'in' when I close the choke on bar.
2. After risin up the float height to about 22mm I think
3. New tires (about stock size)
- consumption is about 7 L / 100km in the city and about 5,8 L/100km at highway but with speed like 80-90kph on avg.
So its still kinda f.. up.:/ I checked the sync of carbs - they are almost perfect - also they are clean and as I told before jets are new.
I don't know how to set iddle mixture if its not the same as idle RPMs (??)
I don't know if I can raise float height any more - nevertheless I still have feeling that my XS is getting flood - mostly because when I drive at constant speed sth engine starts to choke a bit, and when I shifting down with throttle (I don't know how to name it in english) sometimes when I try to rise RPM with throttle at clutch it doesnt react at all (??:|).
So?
suggestions?
Good to hear you've solved most of the problem already. Idle mixture is not the same as the idle rpm screw, there's an idle mixture screw on each of your carbs. Take off the tank and have a look around your carbs, they're in there somewhere Set those, maybe that will fix your running rich and therefore your fuel consumption issues.
Set those, maybe that will fix your running rich and therefore your fuel consumption issues.Can somebody show me them on some kind of photo? What should I do with them? screw out to lean and screw in to rich?
I have few problem also with riding - I feel like my engine is drowning sometimes - so there must be also sth else:/
What should I do with them? screw out to lean and screw in to rich?I have few problem also with riding - I feel like my engine is drowning sometimes - so there must be also sth else:/
well if they're set too rich you could be drowning your engine.. Don't have a picture here now unfortunately but they're located between your carbs (out of sight). Screwing them in will make the mixture leaner, screwing them out makes it richer. If your exhaust and air filters are stock, they should be 2 1/2 turns out as a reference. Go from there and adjust them until you're happy with it. Also check your choke mechanism and see if your cable needs adjusting. It could be that you're still riding around with some of the choke on, that won't help with the gas mileage.
