Just passed 236,000km

[wreckage]

I usually hit reserve around 280 to 300km.

Maybe my carbies are just worn. I know that there's no easy way to tell, apart from replacing them.
My bike mech. said he would be loath to change the main jets from standard and would take some convincing to do so.

By the sound of what you say, dicky, it does seem that the carbs themselves could be my issue. If I can find another set, what should I pay for them, dya reckon?
Trooper Lu says $976 EACH. Sounds a bit rich.

Cheers.

[cobbadiggabuddyblooo]

I'd be questioning the integrity on your mechanic.
Simple do it yourself job to change the needle jet (emulsion tube) and jet needle and kits are available for under $100.
More than likely this is where you issue with fuel consumption lies.
It's a common problem with downdraft carbies and expect to do it every 20-30,000km.

[alextrx850]

Exactly, wreckage...grab the rebuild set that's on e-bay at the moment and fit em up.
Easy too

[SDN]

Must admit to not being any where near 4000 revs, unless stuck in a line of slow traffic with no way past!

[Rod.s]

I usually hit reserve around 280 to 300km.

Maybe my carbies are just worn. I know that there's no easy way to tell, apart from replacing them.
My bike mech. said he would be loath to change the main jets from standard and would take some convincing to do so.

By the sound of what you say, dicky, it does seem that the carbs themselves could be my issue. If I can find another set, what should I pay for them, dya reckon?
Trooper Lu says $976 EACH. Sounds a bit rich.

Cheers.

Put a kit through them, simple and cheep. Drop me a PM and we'll have a look, remember i've already fondled your set of carbs

[dicky]

Carbs don't break, they just get set up wrong.
Go and see Rod and I'm sure you'll get it fixed.
At the most it will cost you a set of seals and a few jets.

[wreckage]

I'd be questioning the integrity on your mechanic.

Oooh.. Where's the love for my old mech. Cobba? Not mentioning any names, but he's got a little workshop in Pickering St. from which he's been specialising in Japanese bikes (admittedly, usually multis) since the mid-80's.
I know you're a bloody TRX genious as are many of you guys, but I can kinda see his point... Yamaha made the bike the way it is for a reason so why change from standard parts unless other major changes have been made? Are you agreeing with Con Rod in that the main jets should be changed from 142.5 to 137.5?

This is where I get confused... one minute I'm advised to change the main jets and the next to put the KY-0570 carb repair kits in, which have the standard #142.5 main jet anyway, and which I've already had done in November last year. It didn't make a speck of difference then to the consumption, either.

Simple do it yourself job to change the needle jet (emulsion tube) and jet needle and kits are available for under $100.

These are the same kits, right? - http://www.motorcyclespareswarehouse.co ... -parts-kit

I've only done around 5,000 klms since then so it's a little early to need to be done again, besides, if I touched the innards of a carburettor myself, the chances of the bike ever running again would be about the same as Wayne Rainey winning another grand prix.

Exactly, wreckage...grab the rebuild set that's on e-bay at the moment and fit em up.

You mean the same thing Alex, right?

And dicky.. sure carbs don't really 'break', but they do wear, don't they?

Rod.s... Yeah, you kindly fondled my carbs, but I'm still looking for my airbox screws...

Seriously, I bow to all your greatnesses and Rod.s, if you really would like to show me how to change the main jets, just let me know what I should buy and I'll pop over and annoy you.
I'm getting it serviced and tuned on Wednesday week (19th), so any time after that would be cool.

[Con Rod]

Oooh.. Where's the love for my old mech. Cobba? Not mentioning any names, but he's got a little workshop in Pickering St. from which he's been specialising in Japanese bikes (admittedly, usually multis) since the mid-80's.
I know you're a bloody TRX genious as are many of you guys, but I can kinda see his point... Yamaha made the bike the way it is for a reason so why change from standard parts unless other major changes have been made? Are you agreeing with Con Rod in that the main jets should be changed from 142.5 to 137.5?

This is where I get confused... one minute I'm advised to change the main jets and the next to put the KY-0570 carb repair kits in, which have the standard #142.5 main jet anyway, and which I've already had done in November last year. It didn't make a speck of difference then to the consumption, either.

You would need to do both. Put Keyster kit in to replace worn jets, needles, o-rings and float valves.

The TRX runs rich stock, pretty much every carbied bike out of Japan does. Yamaha do a carb set up that will need to run well in the cold French Alps, as it does in sunny Brisbane, so they tune on the rich side. A bike that is rich will feel smooth and the power delivery will be softer, too lean and it will feel like it is hunting. Takes a bit of work to get it right.

Being in a warm climate in Brisbane you can run a jet 2 size down, not a whopping change but it will give you more power and better fuel consumption. This is why you would swap the main jet from 142.5 to 137.5. The UK guys might be better with a 140 with the cooler weather

Next up on the TRX is the needle. The needle jets wear oval, I track this and find they need to be adjusted about every 5000km and replaced every 20,000 to 25,000km. This is where you do 90% of the tuning on a bike, by way of adjusting the needle clip. Easiest to start in the middle position. If you have just put a new kit in 5000km ago I would adjust the clip one position leaner and see from there

Finally you have the fuel screw, Yamaha recommends 2.5turns out. I run 2.25 turns out.

Do you get a lot of soot in your exhaust?

Also if your air filter is dirty you fuel consumption will go way up.

Anyway it is a bit of a pain to tune the trx but its worthwhile getting to know haw to adjust the needle jet, with practice it will only take about 15 minutes

Also these are really worth a read, very useful resource

http://www.factorypro.com/tech/tech_tun ... gines.html

http://www.iwt.com.au/mikunicarb.htm

[Rod.s]

I'd be questioning the integrity on your mechanic.

Oooh.. Where's the love for my old mech. Cobba? Not mentioning any names, but he's got a little workshop in Pickering St. from which he's been specialising in Japanese bikes (admittedly, usually multis) since the mid-80's.
I know you're a bloody TRX genious as are many of you guys, but I can kinda see his point... Yamaha made the bike the way it is for a reason so why change from standard parts unless other major changes have been made? Are you agreeing with Con Rod in that the main jets should be changed from 142.5 to 137.5?

This is where I get confused... one minute I'm advised to change the main jets and the next to put the KY-0570 carb repair kits in, which have the standard #142.5 main jet anyway, and which I've already had done in November last year. It didn't make a speck of difference then to the consumption, either.

Simple do it yourself job to change the needle jet (emulsion tube) and jet needle and kits are available for under $100.

These are the same kits, right? - http://www.motorcyclespareswarehouse.co ... -parts-kit

I've only done around 5,000 klms since then so it's a little early to need to be done again, besides, if I touched the innards of a carburettor myself, the chances of the bike ever running again would be about the same as Wayne Rainey winning another grand prix.

Exactly, wreckage...grab the rebuild set that's on e-bay at the moment and fit em up.

You mean the same thing Alex, right?

And dicky.. sure carbs don't really 'break', but they do wear, don't they?

Rod.s... Yeah, you kindly fondled my carbs, but I'm still looking for my airbox screws...

Seriously, I bow to all your greatnesses and Rod.s, if you really would like to show me how to change the main jets, just let me know what I should buy and I'll pop over and annoy you.
I'm getting it serviced and tuned on Wednesday week (19th), so any time after that would be cool.

Mate you've been given great advice by many people and offers to assist, not much more we can do. It's up to you now as to what you want to do and which way you want to go.

Rod

[cobbadiggabuddyblooo]

Mayy I suggest you ask your mechanic to smell the oil when he does your service.
If your bike is a daily commute. and it uses a little oil like most TRX's.
If its a sticky float height issue, you may have a little fuel running into the motor overnite which is topping up your oil level.

[wreckage]

Anyway it is a bit of a pain to tune the trx but its worthwhile getting to know how to adjust the needle jet, with practice it will only take about 15 minutes

Best, clearest explanation I've heard.. Thanks, Con Rod.

I've hi-jacked this thread long enough now.. I'll check for sticking floats too, Cobba... As you recall it's done that before.
Thanks, all.

[Trixed]

Before FCRs I got 260 post FCRs it has been 290+. Did a plug change Cobba and the mixture on the old ones was spot on.
The other bike in vgc and stock carbies gives 300.
236k with no major issues is impressive.

[woolybully]

Erm, been out for a potter this afternoon & just passed 5.7 k, mind you that is miles not kilometers.