another tach question

[Viirin]

You guys are probably sick of hearing the question "will this tach fit?" but i gotta know before i buy this one....will this one fit?

http://cgi.ebay.com/ebaymotors/CHROME-M ... ories#shId (http://cgi.ebay.com/ebaymotors/CHROME-MINI-TACH-TACHOMETER-FITS-SUZUKI-CLAMP-_W0QQcmdZViewItemQQhashZitem4aa5499940QQitemZ32060 0643904QQptZMotorcyclesQ5fPartsQ5fAccessories#shId )

So according to some of the other threads i need one that is set for duel firing right? this one says it is but it says it'll fit any V twin...and there in lies the (first) problem...2 cylinders but not a v-twin right?

I've seen a couple of pics of other GZ's on here with tachs but some of them seem to go up to 12...this one only goes up to 8 - is that enough?

Does the gz have a 52mm cable to connect it or is it a different size one?

sorry about all the questions but i'm saving up my money to get a rake load of things done to the bike during it's next service and i'd figure i'd add a tach to finally get the idle perfect, but also for curiosities sake

Cheers for any responses guy! :2tup:

Vii

[alantf]

The advert says "will fit any V twin". It doesn't mention single cylinder bikes. The marauder 250 is a single cylinder (twin valve), but the Marauder 800 is a V twin, so they may be referring to that. If I were you, unless you can get in touch with the seller, I'd be inclined to give it a miss. :)

BTW I haven't got a tach but it's been said that in 5th gear the marauder 250 does 10mph per 1000 revs, so that takes you up to 80mph. Don't reckon you'll be going any faster than that. :)

What's the 52mm cable you mention? 52mm is around 2", so I don't know what you mean.

[Viirin]

cheers alan, the 52mm cable i think attaches the tach to the engine and as far as i know the port for connecting it is down there somewhere - i seem to remember someone showing it to me before but i can't remember exactly where

[alantf]

Re-read my reply. I posted it, then when I re-read the advert I completely changed my answer.

[mrlmd1]

I don't remember if the GZ is a dual fire ignition or not, but the tach for a twin will work if it is. Maybe someone else can chime in here.
Search for all the threads on tachs, it may give you more information.
All these tachs are electric, not mechanical.

[alantf]

I don't remember if the GZ is a dual fire ignition or not,

It's been mentioned before, that it is.

Wouldn't you need some way of switching between single cylinder/twin cylinder, so that it doesn't show half the true reading (or is that double the true reading?)? :??: I remember fitting one to a car, many years ago, & you had to switch it to the setting for the number of cylinders your car had.

[Viirin]

yeah i think they're supposed to be set for dual fire readings - this one is but if you guys think it might not work i'll look elsewhere

*disclaimer* there may br future postings by me about alternate tachs...sorry

[blaine]

Yes,the G.Z. is a duel fire ignition,and yes this tach will work.Some bikes with twin cylinders are only single fire,therefore this tach would not work on those models. :cool: :)

[Viirin]

oh sweet are you sure? thats deadly

thanks for the help guys

[blaine]

oh sweet are you sure?

Yes,It is a duel fire system. :) :cool:

[alantf]

Yes, but how does it differentiate between a two cylinder & a single cylinder? Surely the twin cylinder only needs to fire each cylinder once every two revolutions, whereas a single cylinder needs to fire every revolution. Doesn't that mean that a rev counter designed for a twin will show double the revs when fitted to a single? Or am I missing something? :??: :)

[blaine]

Yes, but how does it differentiate between a two cylinder & a single cylinder? Surely the twin cylinder only needs to fire each cylinder once every two revolutions, whereas a single cylinder needs to fire every revolution. Doesn't that mean that a rev counter designed for a twin will show double the revs when fitted to a single? Or am I missing something? :??: :)
I don't know how to explain it.I know that a lot of people used aftermarket tach's designed for duel-fire,Harleys,me included.If you come across a simple method of explaining the concept,I would love to here it,as I never understood this fully. :??: It's one of those"I don't how it works,I just know it works".
:2tup: :)

[alantf]

Mmmmmmmmmmmm I'll have to accept that it works :) But I recall a posting some time ago when a guy set his tickover to 1400 revs (using a tach) but was still having problems. He posted a video, and upon listening to it, it sounded as though it was reving at 700. It was thought at the time that his rev counter was showing double the actual revs. :??:

[mrlmd1]

If I am correct, a dual fire ignition fires on every revolution of the engine, even though the power stroke on a single cylinder 4 cycle is every 2 revs. It counts every spark. A 2 cylinder engine also fires every revolution, same number of sparks. Is that clear enough?

[alantf]

Sorry :) This old brain can't get it's head around this :cry:

[blaine]

If I am correct, a dual fire ignition fires on every revolution of the engine, even though the power stroke on a single cylinder 4 cycle is every 2 revs. It counts every spark. A 2 cylinder engine also fires every revolution, same number of sparks. Is that clear enough?
You are correct.Dual fire ignition systems fire both spark plugs from a single coil at the same time.(Two plug wires from one coil).The majority of the spark energy goes to the cylinder under compression while a small portion goes to the cylinder on the exhaust stroke causing a small wasted spark. Single fire ignitions separate the firing pulses,(Two seperate coils) only firing the cylinder under compression. The main advantage of dual fire systems is simplicity and low cost. The advantage of single fire systems are smoother engine operation and the elimination of the popping that sometimes occurs when long duration camshafts are used. There is no horsepower advantage with single fire ignition systems. My older EN450 has single fire ignition,wile the newer Vulcan has a duel-fire ignition.
:cool: :)

[mrlmd1]

Under "How To's", in the "Add a Tachometer" thread, on Aug. 23, 2010 I posted

"If you want to go a different route, ie, a small electronic tach + hour meter, look at Tiny Tach.
http://www.tinytach.com/tinytach/index.php
They can be bought for as low as $40 from eBay and Amazon and other places, are easy to hook up with an inductive coil wire wrapped around a spark plug wire, have an internal battery supposedly guaranteed for 5 years and are totally waterproof, small enough to be mounted anywhere. I saw them on a jetski forum and another bike forum and they seem to work just fine." These require no wiring, no amount of genius to install.

Like all over here, Search is your friend. There are multiple threads on tachs.

Go back to that thread started in Aug 2007 by quimrider, you'll see a detailed pictorial of his installation step by step, and I believe on page 3 you'll see another explanation of a dual fire ignition. Basically whenever the piston is at TDC the coil delivers the spark, whether it's in the compression stroke or the exhaust stroke, ie. there is a spark for every revolution of the engine and that's what that tach is counting. OK? If the engine was a single fire ignition, ie, only firing on the compression stroke at TDC, it would be much more costly as then you also have to sense not only the flywheel position but the cam position. Nothing is lost by shooting off a spark on the exhaust stroke also and it's easier and cheaper to do. So again, Dual fire tachs work on the GZ. :)