my xr getting 195-200km till hit reserves .. that is with pillion and diffuser removed.

i think full tank till dry can get 230-250kms .. haven try before.

anyone here got feel the difference with and without diffuser ? my dad says got better mileage.

>>> so fix back diffuser.

onli diff i can see now is more quiet .. engine dont tend to overheat excessively and no more attention seeking from the tps


1 >anyone got better mileage with stock tank ?
2> is it true engine can spoil if diffuser removed ? (sorry im such a noob)
3> is it true u can get better mileage with diffuser on ?

hi, hope im helping.
its true tat u get better milage wit e diffuser.
i jus fitted mine n im saving quite abit of fuel.
yes it does spoil e engine without e diffuser.
without it, engine will hav to work extra hard n of course causing it get excess heat. so i think its better with e diffuser.
only minor is tat pickup is slightly slower.
1. saves fuel
2. saves engine
3. saves trouble from rov or tp issuing summons on e pipe

ah_ren wrote:

hi, hope im helping. its true tat u get better milage wit e diffuser. i jus fitted mine n im saving quite abit of fuel. yes it does spoil e engine without e diffuser. without it, engine will hav to work extra hard n of course causing it get excess heat. so i think its better with e diffuser. only minor is tat pickup is slightly slower. 1. saves fuel 2. saves engine 3. saves trouble from rov or tp issuing summons on e pipe

The diffuser is a restrictor, nothing more. If you remove it without changing your jettings to suit, it will cause the engine to run hot, and maybe result in engine damage.

If you change (make richer) your jettings accordingly, removing the diffuser will increase power slightly, and the bike will feel more responsive.

What most do is to jet it just right without diffuser, and put in the diffuser for road use. It's ok to have slightly richer jettings.

richer jettings mean more fuel get burnt ?

sorry ah super noob here @_@"

gungrave08 wrote:

richer jettings mean more fuel get burnt ? sorry ah super noob here @_@"

Typically yes. The idea is to have the correct jetting. There is no such thing as a "fuel economy" jetting. It's lean, rich, or just right.

Rich jetting is better than lean jetting, as too lean jettings can result in overheating, and maybe engine damage.

If your goal is fuel efficiency, you will probably need to do the following:
- install diffuser
- fix back air-box snorkel
- use stock exhaust system
- stock air-filter

With such a configuration, you will probably need smaller jets, as your air intake is also correspondingly reduced.

If you remove diffuser, remove air-box snorkel, fix over sized header, fix aftermarket pipe, high-flow air filter, you will have much higher air flow, and will therefore need larger jets to have the correct air/fuel mixture.

Having a larger air/fuel volume will result in a bigger bang, which typically means more power, and vice versa.

Hope this makes it more clear.

thanks for e correction. hope to learn more in future

thanks for the input new_dirt =)

ok quest to look for these items

- install diffuser (done)
- fix back air-box snorkel (bike comes without it)
- use stock exhaust system (bike bought with oversized header and stock end)
- stock air-filter (bike comes without it)

if you so decide to sell your oversize header, i may be interested..

supernov@ wrote:

if you so decide to sell your oversize header, i may be interested..

i knew it! idiot..

kenasai you.. looking out for a friend la.. my xr4 no need bling&power cos rider no time to hone skill.. kehkehkeh...

ermm.. What's the worst milage you should see on an XR4. Just got mine like 4 weeks back and it looks like 15km per litre. I might be wrong. My tank empties itself when it is in 'on'. So got no reserve back up. So i calculated by filling full tank, ran like 120km then refilling it again to full to see how much fuel was lost. So unless somebody has been stealing my petrol while i sleep, i think i'm getting 15km/l.

if ure really getting that kind of mileage, go have a bike check up. ur jettings, petrol fuel line(fuel hose), petrol petcock leakage..


try to check for any oilspill after parking overnight at the lot. if there is oil, be a man, dap the oil with ur finger to smell whether is it petrol or other oil leaking. diagnose ur own small problems b4 gg to mechanics.

and please dont wipe the oil stain on ur finger on other bike's seat.

dannyboy wrote:

ermm.. What's the worst milage you should see on an XR4. Just got mine like 4 weeks back and it looks like 15km per litre. I might be wrong. My tank empties itself when it is in 'on'. So got no reserve back up. So i calculated by filling full tank, ran like 120km then refilling it again to full to see how much fuel was lost. So unless somebody has been stealing my petrol while i sleep, i think i'm getting 15km/l.

bro, u using stock(9.4625ltrs) or aloop(about 7ltrs) with shrouds? and using stock carb or fcr? if both are stock, you can get at least 22ltrs per litre if your carb is jetted nicely...if its leaner, it's possible to get 25ltrs per litre but engine runs hotter...

here is a webby u can clear your doubts regarding XR4s...got jetting info also for stock bike...might be useful for all including thread starter...i shared this link before few yrs back...sharing it again for all to learn...

http://john.rushworth.com/Pics/XR400/XR4FAQ/

its best if u can figure out ur bike on your own...it'll definately help in future...

hope it helps...cheers...