Yamaha TRX850 Enthusiasts Forum

My bike has a distinctly fuelly aroma all of a sudden - i thought it was due to brimfilling the other day, however it seems to now be doing it even though i am only 2/3rds full.

my garage smells - and i only got 30mpg out of it.

Any idea which hose i should look at first?

Could be a float needle sticking,leading to the carb flooding(unlikely to be both carbs)or the main fuel hose to the vacuum fuel pump,maybe even the vacuum pump itself.
Check for a leak at the fuel tap itself,either the tap seal to the tank or the tap assembly/rotor seal.
By carefully feeling around all the pipes,joints,carb bodies,etc one by one and regularly checking for any wetness or petrol smell on your fingers you should pinpoint it.

troublemaker wrote:My bike has a distinctly fuelly aroma all of a sudden - i thought it was due to brimfilling the other day, however it seems to now be doing it even though i am only 2/3rds full.

my garage smells - and i only got 30mpg out of it.

Any idea which hose i should look at first?

30mpg points towards worn tubes

that said, fuel shouldn't flow when the bike is not running.

As has been said, have a good check around the fuel pipes and the carbs for leaks. Also, have a check of the tank for split seams / rust.

Definitely check seal between fuel tap and the tank itself. Mine went with similar results.

phuk72 wrote:

troublemaker wrote:My bike has a distinctly fuelly aroma all of a sudden - i thought it was due to brimfilling the other day, however it seems to now be doing it even though i am only 2/3rds full.

my garage smells - and i only got 30mpg out of it.

Any idea which hose i should look at first?

30mpg points towards worn tubes

that said, fuel shouldn't flow when the bike is not running.

As has been said, have a good check around the fuel pipes and the carbs for leaks. Also, have a check of the tank for split seams / rust.

...and check which position you leave your fuel tap in. Should be left "on" (pointing down) cos if you put it "off" (pointing up) this allows fuel to flow freely.

...also diaphragm rubber in the fuel tap can split too.

Give it a good wash/dry and then sit and watch to see where she dribbles!

trixynut wrote:...and check which position you leave your fuel tap in. Should be left "on" (pointing down) cos if you put it "off" (pointing up) this allows fuel to flow freely.

...also diaphragm rubber in the fuel tap can split too.

Give it a good wash/dry and then sit and watch to see where she dribbles!

Not that I've used it for ages but isn't up reserve? If the fuel cock is horizontal that's prime?

the tubes were done when i got it by a previous member on this forum - they have factory pro's in - surely 1500 miles they wont be worn out lol.

Check the positioning of the drain tubes on the carbs - I've seen them syphon out on TDMs - you'll tell by dampness at the ends of them. The dealer put plastic "U" tubes (like in yer lavvy pan, but smaller ) under warranty - cured it!

My local dyno,engineering and tuning shop reckon that they can be fooked within 5 or 6000 miles though!
Especially if a lot of town work(low revs,tall gear,constant throttle changes)are taken in,the needles actually rattle within the tubes as do the slides in their guide.
An engine running more smoothly at higher revs puts much less wear on them.

troublemaker wrote:the tubes were done when i got it by a previous member on this forum - they have factory pro's in - surely 1500 miles they wont be worn out lol.

Don't be surprised if they are. I got mine done about 2 years ago, replaced with Factory Pro, and I'm sure these are worn already. Gotta get those FCRs one day!

Bob

FP are harder than Yam ones - no appreciable ovalling after 15k miles when I checked mine on my old TDM850 - don't "lug" the engine at low revs as mincehead says - thats the reason Japanese cruisers wear theirs out in no time.

I think the grade of brass Factory Pro use might be more resistant to the wear,also are their tubes not nickel plated too?
Nickel is much better at resisting wear than plain brass,although there are grades of nickel brass too.
I used to machine a grade of brass that was CZ114,one of the best for wear resistance,here folks you can see for yourself:

http://www.conexmetals.com/brass_compon ... onents.htm

Here`s brass `hardness` listings:

http://www.metal-mart.com/Guides/Hardness_brass.aspx

And nickel:

http://www.metal-mart.com/Guides/Hardness_Nickel.aspx

You can clearly see how much harder nickel is.

You could also check your fuel tap.The pipe that is the outlet from the tap is not supposed to swivel around and if it does you might have a leak there.