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Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Sun Jul 01, 2012 6:11 am
by Jordy
Just inquiring how to get the best rpm/tacho reading for my digital dash.
I Currently have tried the factory fires grey,brown,black which used to run the factory dash but that didnt work.
I have wrapped the wire around right coil lead ,sitting on bike , and the works o.k but jumps around on idle .
i have the ppr setting on dash to set to 1. but it dosnt matter which setting it is, still jumps around .between 1000-2000 on idle .
Re: Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Sun Jul 01, 2012 10:17 am
by Mincehead
Yes it`s often a problem on after market tacho`s. Have you contacted Trailtech direct?
Their UK head office is not far from me at Galashiels:
http://www.trailtechproducts.co.uk/cgi- ... N=SHOWFORM
http://www.trailtechproducts.co.uk/
Re: Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Sun Jul 01, 2012 10:33 am
by Jordy
Ive just been doing some research and my rpm/tach wire does not have a resistor in it. in my kit when i got it the power and rpm wires where identical, and after researching vapor are now making these tach wires with resistor in them , ive seen one forum someone reckon you could use a 600 ohm resistor and wire it in, i may try that tom a resistor would only be worth maybe $2 .
Re: Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Sun Jul 01, 2012 10:45 am
by Mincehead
Best check with them first, an email costs precious ferk all.

Re: Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Tue Jul 03, 2012 7:13 am
by Jordy
Sorted Issue.
Brought a 620k ohm resistor , came in a pack of 5 , for 0.49cents.
Only need one but u have some spares in case .
The problem is the current to the tacho on digital dash is too high and inconsistant.By installing a resistor in parallel on the t red tacho wire to dash unit it lowers the current through , and makes it more consistant.
Also now trailtech vapor are now making there tacho wires with 600k ohm resistors in them . That is the fix .
Also to get the best reading from the trx, i have taped the tacho wire into the grey wire on right coil (sitting on bike).
Now my tacho reads PERFECT right through rev range and dosnt jump at all.
Re: Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Tue Jul 03, 2012 8:16 am
by Mincehead
Good job done then.

Re: Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Wed Jul 04, 2012 6:48 am
by Jordy
Re: Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Sat Jun 29, 2013 12:50 pm
by Dion31
I love this forum especially for this reason:)
Cheers Jordy!
Your fix has worked a treat

Re: Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Thu Aug 15, 2013 9:06 am
by Jordy
No worries Dion.
What are forums for aye .
Glad my information could be of some help.
This forum is just awesome for info its helped me out heaps already.
Re: Trx 850 Trail Tech Vapor Digital - Best Rpm Reading
Posted: Mon Sep 01, 2014 2:08 pm
by FANDANGO
Hi,
Apologies if this is a bit thick but is it a 600 ohm or 600,000 ohm resistor as there are two sizes mentioned in the posts. Also, to fit it does it go in the positive feed or across the two wires. Hope that makes sense. Thanks