Yamaha TRX850 Enthusiasts Forum

my bike is in with my mechanic at the moment.shes got a flat spot between 1000-3500 but then comes to life and goes great,but when you open the throttle right open,she splutters and struggles to get up to high revs.when you roll the throttle on slowly it goes ok to fine.
my mechanic has tried all types of jetting setups but cant seem to get it right.
as far as i know the motor is stock and i am now running the standard pipes on it.
have any of you guys experienced these problems before and how where they rectified?
the bike hates taking of on hills and requires alot of work to do so.
i just got of the phone to the mechanic and they where trying a new float level.
any ideas?

Could be the dreaded emulsion tube syndrome. Get the mechanic to check these and see whether they have ovalized.

Like he said ^^

Emulsion tubes for sure.

Stop your mechanic wasting your money and change them yourself.

the bikes got 38000 on it.how long do you normally get out of em?
how much are they worth in oz?

Changed mine at 46,000 km, can't remember the cost cause I did a deal with my mechanic

They can be dead in 5000 miles of town riding.

Mate,
I had a similar problem which turned out to be the carbs needing balancing. Bikeshop did it and all was fine. Just a suggestinon to try.
Dave.

i had that along with bad starting and that appeared to be the Tubes as suggested by most and pointed in the right direction by youngy

revs great now and there not too hard to fit

if the mechanic is already doing your floats he may aswel ust change the tubes whilst he is on

yeah just got of the phone to mech,tolled me they changed tubes a month ago when first took it in there, when it first showed signs of trouble.
they said they spent almost all of yesterday working on it,but couldnt figure it out.
not gonna charge me, so now im looking for a mech in sydney who knows
trx's
anyone know?

P.S what are stock carbs going for?

Probably bikebiz in parra. Mick Dyers in penrith also seem to be okay with TRX's. Have you tried putting a standard air filter in ? Has the airbox been modified ? What gearing are you running ? It may not be a flat spot. TRX's are sedate below 3500. Putting the standard pipes back on may have just made it stand out more.

Maybe a dyno run is needed to take the guessing out of the equation. then can check the AFR at various RPM's under load. As twolfe says, the TRX at below 3000rpm (mainly in the higher gears) can pig-root a little normally.

If you are stuck for standard carbs airbox or k/n filter I have'm sitting in the shed unused

its got standard airbox with k&n on it.thanks bob
im gonna get another opinion tomorrow(thats if the boss gives all clear)
are there still mechanics who specialize in carbs?
i just think its gotta be carbs.

Remember sometime ago someone here had a carby problem and it ended up being a hairline crack in the carb body. scroll through the info on this site and see if his symptoms are the same as yours. Good luck.

got it back this morning.got another set of carbs from the wreckers and now the flat spots are gone,but she is still suffering from some hesatation when the throttle is guickly fully open.im now thinkin weak spark.has anyone here had to replace coils and how does the bike behave when there gone or how does the bike behave when 1 is gone?
the original carbs show no signs of any thing wrong,but when on the bike are crapola.
p.s im in deep shite at home for spending $500 on my bike.
in the next few days will post my costom made pipes for sale along with other bits.