blktoy35 Posted August 23, 2010 Report Share Posted August 23, 2010 i installed a tacho in my ke 35.. its 52mm cheapy where the clock normally goes, its got settings on the back for 4,6,8 cylinder.... its all wired correctly and is set on 4 but appears to be reading double.......idle showing 2,000 rpm and as revs build goes all the way to 7,500rpm to easy.. don't think the 3k will see those revs lmao.... the tach signal ive taken from the - on the coil... been told need to put a resistor on the wire..is so how many ohms?? before i put the resistor on what will happen if i set the tacho at 6 or 8 will that potentially fix the issue? :jamie: Quote Link to comment Share on other sites More sharing options...
ke70dave Posted August 23, 2010 Report Share Posted August 23, 2010 all the switch does it change how many pulses it reads as one revolution. so if its on 4 it will read 4 pulses to 1 rev. if its on 8 it will read 8 pulses per rev. try switching that switch around and see if it gets more accurate? in fact if its reading double, try it on "8". essentially should halve what the tacho is showing if you have it on "4" at the moment. how cheap are we talking here? maybe the switch sticker is wrong?:jamie: also shouldnt need a resistor. Quote Link to comment Share on other sites More sharing options...
blktoy35 Posted August 23, 2010 Author Report Share Posted August 23, 2010 yes ill go ahead and try set it on 8... i was thinking it should half the signal doing that but thought id run it by here first... cheap as in $45 off evilbay... but it changes to 8 colors that works great haha..... to bad it don't read right! Quote Link to comment Share on other sites More sharing options...
Toy-Yoda[RL] Posted August 23, 2010 Report Share Posted August 23, 2010 It should have come with a small resistor in it's packaging...... When used on a points style ignition system, that little resistor is essential to getting an accurate signal, setting it to 8 will just make it jump around all over the place unless you happen to be particularly lucky.... Have a chat with someone down at somewhere like Autobarns and see if they'll show you the type of resistor that comes with the new ones, the resistor will cost you about 25c from Dick Smiths :jamie: Quote Link to comment Share on other sites More sharing options...
blktoy35 Posted August 23, 2010 Author Report Share Posted August 23, 2010 yeh the tach didnt come with any resistor as such.... i will try and set it a 8 see what happens otherwise get the resistor idea going... hopefully someone in here knows the right resistor to use... Quote Link to comment Share on other sites More sharing options...
RO-81-LA Posted August 23, 2010 Report Share Posted August 23, 2010 i have the exact same problem and am ringing everywhere and they can't tell me what size resistor i need. i have hookd up a saas 2 1/4 inch tach, using gt40r coil. please help!! Quote Link to comment Share on other sites More sharing options...
blktoy35 Posted August 23, 2010 Author Report Share Posted August 23, 2010 (edited) i just sussed out the online manual for my tacho on the trisco website http://www.trisco.com/manuals/LED%20TACHOMETER.pdf , and it shows it can select between 3,4,6 maybe in asia?... not 4,6,8 as the sticker on my tacho and instructions show...so maybe i got the one with wrong settings... ill will report back what i find when i switch it around.... Edited August 23, 2010 by blktoy35 Quote Link to comment Share on other sites More sharing options...
Evan G Posted August 23, 2010 Report Share Posted August 23, 2010 (edited) pardon me but did someone say resistor before toy-yoda? :jamie: i found the resistor that came with my tacho, ill measure it tomorrow and report back! Edited August 23, 2010 by Evan G Quote Link to comment Share on other sites More sharing options...
blktoy35 Posted August 23, 2010 Author Report Share Posted August 23, 2010 evan g did mention a resistor to me haha.... i had a tinker tonight and switched to the aparent 6 setting and now the tacho idles bang on 1000rpm and revs climb how k engine should....so in my case the tacho is shit may have been packaged as 4,6,8 but is reality 3,4,6....... Quote Link to comment Share on other sites More sharing options...
Evan G Posted August 23, 2010 Report Share Posted August 23, 2010 3,4,6 LMAO! pov pack oright! Quote Link to comment Share on other sites More sharing options...
flamingheads Posted August 23, 2010 Report Share Posted August 23, 2010 I did the clock install thing and had the same problem and now have mine set on 6, which seems to be right. Weird. Quote Link to comment Share on other sites More sharing options...
SLO-030 Posted August 24, 2010 Report Share Posted August 24, 2010 Pretty sure i had the same sorta tach in my KE25 (8 colour thingo) had to set it to 6 or 8, i can't remember :) All i remember is that i could swing the needle off the 12,000rpm dial with a 3k. :) Quote Link to comment Share on other sites More sharing options...
Trev Posted August 24, 2010 Report Share Posted August 24, 2010 (edited) Having a tacho set to 8 on a 4 reading half is a myth, I have found that it is normally the other way around and it was also the cause of a tacho install on ae82.net and a tacho I put in my ke36 did the same (3000rpm idle). ive got it grounded to a part that connects to my ignition but it seems waaay off, its in front of my temp/fuel gauge What do you mean it seems way off? at at about 70 mph it's reading 5k Have you got it on the right setting? i fixed it, it was 8 and not 4cyl I thought it would of been. Grounding can make it read different but the input is what you should check first. Don't worry about a band resistor, just get a variable 'ohm' resistor and that way you can adjust it accordingly, autometer specifies to use one if the tacho has reading difficulties. EDIT: Resistor and fitting guide: http://www.ehow.com/how_5019464_wire-variable-resistor.html Edited August 24, 2010 by Trev Quote Link to comment Share on other sites More sharing options...
blktoy35 Posted August 25, 2010 Author Report Share Posted August 25, 2010 anyone with this tacho pictured most likley when set on 6 is in fact suitable for 4 cylinder....seems like a few people on here have had this glitch... Quote Link to comment Share on other sites More sharing options...
71-BEETLE Posted August 25, 2010 Report Share Posted August 25, 2010 Hey guys, i had the same issue with my VW Beetle, loved revving it to like 8000rpm cause it didnt have a resistor, the resistor you need is a rectifier diode. From dick smith its part number is IN4004, or it may be replaced by IN4007. If you keep it out of the engine bay and well insulated itll give you the correct reading on 4 cyl engines. They are cheap as and only take 2-3 days to get delivered if you buy online, which is easier then trying to find a store with them Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.