Yamaha TRX850 Enthusiasts Forum

Hi everyone just joined got to say this site is awesome had my trx about 10 years now finally found a place to share mods awesome
Anyway better stick to topic/question don't know if anybody has heard of this but years ago l saw something about modding the ING box on the trx to stop the ING retard at low revs IE 1st and 2nd gear does anyone know anything of this?

Not heard of your topic, only the high RPM limiter in the import bikes....
Suggest you might have a fuel issue more so.

Might you be referring to the full advance for a not having a TPS fitted ?
The TPS is the throttle position sensor fitted to the left side of your carbs, IF, it is working as it mostly does..it will give the advance...retard ...as the ignition module needs.
The Mikuni original carbs have a shaft with a flat blade end that will ensure the TPS is turning to the throttle control..
So being ,there shouldn't be any retard more than usual unless you have a malfunctioning TPS.

Assuming you don't have FCRs without the TPS bracket ?

Hi there,no there's no issue its something l came across few years back from what l remember reading Yamaha did it to soften the power delivery in 1st gear It might not even be possible just asking has anyone come across it
No don't have fcr carbs but am looking to purchase some if anyone knows of any for sale?

stuaxt wrote:Hi there,no there's no issue its something l came across few years back from what l remember reading Yamaha did it to soften the power delivery in 1st gear It might not even be possible just asking has anyone come across it

Ah, ok, not a problem, where are you in the world ?

I am in Blackpool in the sunny uk will get around filling my profile soon

stuaxt wrote:I am in Blackpool in the sunny uk will get around filling my profile soon

Sweet, regards from down under, photo of the bike ?

Regards from the UK mate too,sorry no photo till tomorrow bloody website won't let me upload from me phone l will get on the PC tomorrow .Bike is pretty much stock apart from thundercat front end anyways nearly 2.00am gotta sleep upload PIC tomorrow ,take it easy

http://www.autospeed.com/cms/article.html?&A=109132

Some light reading on timing .

The std ECU is a non programmable ignition unit and has a ignition curve set in from the factory to deal with different RON rates of fuel from around the globe and to aid in emission control with some parts of this universe being rather anal on this side of things.
So you effectively have a happy medium and not specifically an optimum timing curve on the std ECU.
The TPS gives you a 3D map from the set curve to deal with load.
As Alex mentioned there is a documented thread on the forum that shows a modification to bypass the TPS if need be.
This will lift your Rev limiter by 500rpm from 9250 to 9750 and set your ignition to run at a full advance state throughout the rev range.
Aftermarket programmable ignitions are available for the TRX which will give you close to the optimum timing especially benificial in the lower/midrange part of the curve and also allows to you program the timing to deal with any modifications.
The link above gives you an insight into fuel mixture, emissions, cam timing and compression ratios and how these all impact on timing.

Ever farted and not quite got the timing right and detonation was only a few degrees away..

What you suggest, altering the power regarding to selected gear, is impossible on an original TRX as the CDI unit does not know which gear is selected. The neutral sensor has only one contact (being neutral).
The TDM and YZF750R, both from '96 or later, have the same neutral switch but these also have connections for all the gears. (This is easy for a home-made gear indicator btw viewtopic.php?f=6&t=4389 ).
I owned a YZF750R '96 and the first two gears were actually connected to the CDI unit, so I do believe the power was limited in these gears to some level (I never noticed nor felt the urge to undo these limits).
This could also account for the younger TDM models, but certainly not for the TRX - just because of the neutral switch.

Thanks for the info guys was aware that the trx doesn't have have a gear position sensor didn't know the yzf and tdm did this is probably what l was reading about and whom ever wrote it must of made the assumption the trx was the same.kinda answers my question but please now where can l purchase a programmable ING from?

Ask cobba.

viewtopic.php?f=33&t=9910#p101013

Cobba is in Aus and I see Stuaxt is in the UK.
You can order from http://www.ignitech.cz/en/ directly, all the info is on their website.
Fast delivery - I had mine within a couple of days.

Thanks guys