Yamaha TRX850 Enthusiasts Forum

Hi all, Looking into getting the new emulsion tubes & needles for my TRX & hoping someone on here can assist with my queries. My bike is all stock except for carbon cans & runs fine (jetting etc all seems ok) - does the Factory Pro kit suit standard bikes or are they more for modified ones - ie: are the needle specs etc the same as standard or will we need to re-jet it to suit? I haven't priced the genuine parts yet but can get the Factory Pro kit for AUD $155.00 which seems ok to me - not so cheap if we have to retune it to suit though?
The only guy over here that I would trust to dyno my bike isn't interested in doing carbed bikes any more so this could be a problem.

I have checked out the spare parts manual on here & just want to check that I've got all the info correct before I ring my local yamaha dealer for prices - do we know if the carb parts are the same part # for European models & Australian bikes?
What are the numbers 4UN3 & 4VN2 at the top of the part number listings - are these just ID numbers for the 2 different carbs? - are the carbs the same for all markets?

I reckon the parts on the diagrams are as follows: Emulsion tubes - #35, Needles - #28, needle & seat assy - #24. - am I correct?
According to the parts list, the 2 carbs have different needle sets - is this correct?

Bottom line - am I better off going with the std or Factory Pro parts?

Thanks in advance for any assistance & opinions. pbear62

Mate I cannot answer all of your questions but I think you will find that with the
AU$ against the American $ you would be well advised to buy direct from Factory Pro in the States.

Fung priced Original needles and jets and they were hideously expensive, where as Factory Pro direct from the States about $150US
http://lmgtfy.com/?q=Factory+Pro+trx

Factory pro. The emulsion tubes are coated so should last longer than raw brass (standard) & the needles have a different taper for better throttle response.

You will be fine with a standard tuned engine. IIRC the parts from Yamaha were dearer or similar in price...

True, I used a Factory Pro kit a few years back and my throttle response and mileage improved dramatically.

Bob

+1 Factory Pro emulsions and needles, had them set up on a dyno and they have been great

Thanks for the info guys - hey MV, you said the needles have a different taper to std ones - surely this is going to change the mixtures
(or is the ID of the Factory Pro emulsion tubes correspondingly smaller than std as well?) As i said in my original post, the dyno tuner I
know over here isn't interested in doing carbed bikes any more so if I need to rejet it to suit F-Pro parts, I'm stuffed! Wombat - did you
get yours rejetted or did you just put the F-Pro bits in & run it as it was?

Yes the needles taper corresponds to the emulsion tubes. Never used them myself but folk that have seem to be happy with the results.

Hi Mince - thanks for the quick reply. Looks like Factory Pro is the way to go. Sorry to harp on about this but I only
want to buy the bits once & want to make sure I get it right first time. When you say that the tubes suit the needles
- I know that this is the principle of how carbs work but to clarify - do you KNOW for sure that the F-Pro tubes are
smaller on the ID than std to suit the thinner needles? - obviously if the needles are thinner than std but the tubes
are same ID as std it's not going to be right. I've spoken to the F-pro distributor in Aust & they haven't been able
to confirm this. to quote them - "yeah, we've sold a few sets"

Not sure of the dimensions of the taper but they`ve done their research and matched the taper of both the needles and the tubes to lean out the rich mixture that the standard Yamaha needles tend to give at some throttle openings.
MANY menbers here swear by them, you`ll find them to be good I`m sure. Remember though, an hour or two on a dyno getting the fuelling right is money well spent.

+1 when i fitted the factory pro parts, I messed about with my carbs for ages to get them some where right, but couldn't get them spot on. Dyno guy got them spot on - wish I hadn't wasted so much time

pbear62 wrote:Thanks for the info guys - hey MV, you said the needles have a different taper to std ones - surely this is going to change the mixtures
(or is the ID of the Factory Pro emulsion tubes correspondingly smaller than std as well?) As i said in my original post, the dyno tuner I
know over here isn't interested in doing carbed bikes any more so if I need to rejet it to suit F-Pro parts, I'm stuffed! Wombat - did you
get yours rejetted or did you just put the F-Pro bits in & run it as it was?

You can just drop the Factory Pro kit in & it will run fine. Rich, but fine.

I wanted the tapered needle becasue it has 5 steps for tuning rather than 3 like the standard, & I spent a lot of time setting them up correctly for a little gain (around 5 hp confirmed on the dyno) & much better throttle response.

If you can twist the dyno guys arm to do a run (no tuning, just a run with A/F & HP) then you've got a benchmark for tuning.

That's if you want go that far, like I said, it will work fine out of the box.

pbear62 wrote:Hi Mince - thanks for the quick reply. Looks like Factory Pro is the way to go. Sorry to harp on about this but I only
want to buy the bits once & want to make sure I get it right first time. When you say that the tubes suit the needles
- I know that this is the principle of how carbs work but to clarify - do you KNOW for sure that the F-Pro tubes are
smaller on the ID than std to suit the thinner needles? - obviously if the needles are thinner than std but the tubes
are same ID as std it's not going to be right. I've spoken to the F-pro distributor in Aust & they haven't been able
to confirm this. to quote them - "yeah, we've sold a few sets"

From memory, both e tubes are identical apart from the coating.

From my understanding, the needle taper affects the midrange throttle respnse only, diff taper, diff throttle response. The needle has 5 steps for tuning (moves the needle up or down) so you will always be able to tune it to suit.

Sorry I can't be more technical, that's the depth of my knowledge on this one, but I do know they work.