A new type of fuel mod
 

Hi, I'm a long time member of the forum and proud owner of a 2004 xt660x, and i'm writing from Italy.
During last year I've tried many possible solutions to minimize the typical on-off problem of this bike.

These experiments just ended with a new type of fuel mod that i think could be interesting for the community.
The main problem with the classic fuel-mode obtained adding a trimmer ins series with the NTC is that the correction is not linear due to the non linear behavior of the NTC.

In fact for instance a 1kOhm correction changes the temperature read by the ECU by ,more or less 5�C when the real temperature is 10�C and by over 20�C when the real temperature is 40�.
This causes an engine behavior that's changes together with the outer temperature.
It would be much better to have a linear correction over all the temperature range.

This is possible by adding another NTC in place of the trimmer.
To guess the correct value of this NTC you can simply:
- measure the resistance of the original NTC @ 25 �C (1.9Kohm fom me)
- found the optimal correction (in Degrees) that allows your bike to run smooth (form me is around -5�C)
- put a resistance or set the trimmer to obtain that correction (around 500 ohm for me)
- Buy a NTC with the correct resistance @25�C (i've bought a 470Ohm @ 25�C NTC)
- Put the NTC in series with the original one and put it on the air flow (another hole in the snorkel?)

That's all.

This type of mod is not comparable to a system like a power commander, but works much better than a single trimmer for me.
I'm sorry if my english is not so good but i hope my explanation will be understandable and useful for you too.

Gabriele :109:

Grazie Gabriele, noi ti capiamo e apprezziamo i tuoi suggerimenti.

Cortesemente, manda un private message con il diagramma e le specifiche delle resistenze usate al nostro esperto meccanico Kev cosicche' lui potra' fare delle prove e verificare se funziona uniformemente su tutte le XT.

Grazie ancora e cordiali saluti.

Ottimo, la lingua ufficiale � diventata l'italiano?:-) tempo di fare qualche foto e recuperare i diagrammi e mando tutto, magari in serata o domani :001:

No la lingua qui' e' sempre l'Inglese pero' sei fortunato che io sono italiano.

:sunny:

This mod has been around for a few years now.

I have tried this mod before & the only draw back with this mod is it can not be set for a wide range of mods when you are trying to market a fuel mod.

You need a different NTC resistor resistance for different mods, fuels, altitudes & temp all require different resistances, so one resistance of NTC resistor will not work for everyone around the world.

The mod works well if you know the exact resistance you need for all your mods.

Thanks Kev for your clarification :YouRock: