CARB Synch with Digi Tach

[Seaking]

Hi guys.. so here I am with the little digital tach that you wrap one wire around your spark plug wire, press S1 to set how it reads either single fire, double fire or what ever else it does.. It has the S2 and S1 button on it..

 

I'm getting set to Synch my carbs and hooked up the little tach device and now *I* have that bovine look of incomprehension on my face as to what I'm reading..

 

At idle, I'm either reading 550 RPM or 2300 RPM in either S1 or the S2 reading.. HUH?

 

I thought the idle rpm was around 900 rpm on this thing.. but when I jog the throttle up to 1000 rpm it sounds higher rev that what I had synch'd at with before..

 

Can someone illuminate me as to what "Idle RPM" should be..

 

and what setting should this digi tach should be set at? I know it's a dual fire ignition system, right?

******************

 

Ok so AFTER using the dual fire setting on the tacho, and reading in the book that the engine should be set at idle (roughly 1000 rpm) I synch'd up my carbs, which were WAY off after this winter..

 

So yes, the engine sounds like I am now adjusting it at a much higher rpm sound than before, however, this is a HIGH rev sound for leaving your bike at "idle"??

 

It sounds too much like an engine at idle with the carb heat (choke) left on full... ??

 

If I drop it to where the shops tend to leave the idle its now closer to 600 rpm.. smooth.. not chuggy.. taste great, less filling kind of sound.

 

This was my first carb synch with the digital tach and yeah it was nicer and easier..

 

ONE thing I noticed though that causes me issues when making adjustments. Either settings phillips screw, if you push against them the idle speed drops.. if you leave it alone it will come back.. so when I place the phillips screw driver against the screws, I have to be ever so gentle with it.. so to not muck up the idle rpm setting while adjusting.. is this common?

 

Thanks again.. let me know what you think..

 

Cheers

Edited April 11, 2010 by Seaking
After the Synch:

[dingy]

Attached is the tach manual.

 

Press and hold the S1 button for 4 seconds.

 

Hold it until it displays 01 (spark plug fires once per revolution)

 

I think this is the correct setting, if not also try 02 (spark plug fires twice per revolution) or 03 (spark plug fires every other revolution)

 

Gary

[Seaking]

Attached is the tach manual.

 

Press and hold the S1 button for 4 seconds.

 

Hold it until it displays 01 (spark plug fires once per revolution)

 

I think this is the correct setting, if not also try 02 (spark plug fires twice per revolution) or 03 (spark plug fires every other revolution)

 

Gary

 

Thanks Gary, I had the manual with me but couldn't figure out which setting is appropriate for our bikes.

 

The tach unit defaults to 02 which is single fire. We need to set ours to 02, double fire. And when you run the bike, the numbers now make more sense this way. Though I synch'd the carbs at 1000 rpm (manual states that this is the idle set speed??) I then brought the rpms down to something that sounds more reasonable which is indicated around 580 / 600 rpm... But I'm not sure if this is the proper setting.. it certainly 'sounds' like the proper setting..

 

Test rode the bike and wowsers.. SMOOOOTH now.. hehe.. nice..

[dingy]

OK, I thought the factory default setting was 02.

 

I would have thought that the spark plug fires every revolution due to the fact the pick-up coils read off the end of the crankshaft and not a cam shaft.

 

I haven't used mine yet but any day now.

 

Still can't get the front brakes to bleed right.

 

Got the clutch & rear brake, but the fronts are not cooperating.

 

I have new everything in there, rebuilt master, caliper and new lines. Same with the clutch & rear brake, they bled easy.

 

I have tried a mighty vac, have speed bleeders, but nothing is working yet.

 

I can draw fluid through, but no pressure.

 

Gary

[LilBeaver]

I believe I had to set mine to the 02 setting in order to get it to function properly despite the instructions indicating that is the setting for 'one fire per revolution'.

 

Also, make sure that you have the wire wrapped around the lead 2 or 3 times (minimizes noise).

 

have you tried a different spark plug wire? Maybe you are having an issue with that particular wire or something

[1 Canuck]

[

 

Still can't get the front brakes to bleed right.

 

Got the clutch & rear brake, but the fronts are not cooperating.

 

I have new everything in there, rebuilt master, caliper and new lines. Same with the clutch & rear brake, they bled easy.

 

I have tried a mighty vac, have speed bleeders, but nothing is working yet.

 

I can draw fluid through, but no pressure.

 

Gary

 

Hi Gary,

 

If you haven't already done this...try bleeding the master at the master cylinder itself, then work down to the calipers. If there is any air up top you'll never get pressure.

I have other suggestions if that doesn't work.

 

Cheers,

[Seaking]

I believe I had to set mine to the 02 setting in order to get it to function properly despite the instructions indicating that is the setting for 'one fire per revolution'.

 

Also, make sure that you have the wire wrapped around the lead 2 or 3 times (minimizes noise).

 

have you tried a different spark plug wire? Maybe you are having an issue with that particular wire or something

 

I had several wraps around it and the revs held relatively steady to the engine noise.. I'll try different plug wires next time as well.. see if that changes anything..

 

Thanks