Carb Tuning - Plug Chop Alternative/Compliment?

[pete]

I've been thinking for a while now about tuning my carbs once I get my exhaust done and my pods mounted.

There's the simple and straight forward plug chop method which will tell you if you're running rich, lean, or right.

I was wondering if there was a way to get a better idea for someone like myself who isn't that experienced with interpreting the colour of the plugs, and I've come across two kits from an electronics place I used to work at years ago.

http://www.jaycar.com.au/productView.asp?ID=KC5195&CATID=25&form=CAT&SUBCATID=347

http://www.jaycar.com.au/productView.asp?ID=KC5485&CATID=25&form=CAT&SUBCATID=347

The first one's very simple and cheap although the second is a bit more expensive but more advanced.

The big question is if either is really worthwhile and also how to go about selecting and installing an EGO sensor.

With a 2 to 1 or 4 to 1 exhaust, a single sensor will work after the collector, but it would naturally be better to have a sensor in each pipe to see if one particular carb is out of tune.

I've got no definite plans to pursue this right now, but is definitely something I'll have a bit of a look into to see if it's going to be worth the effort.

Also, if I decide to do it before getting my exhaust made, I could potentially get the exhaust guys to make a fitting for an EGO sensor while it's being made too.

Unfortunately I haven't found any details yet as to what sensors they work with and if they're adjustable for different sensors.

Anyone have thoughts on these?

[Steve]

Unfortunately I haven't found any details yet as to what sensors they work with and if they're adjustable for different sensors.

Well, I think I see the answer in the second link:

Designed to monitor a wideband oxygen sensor and its associated wideband controller ...

They appear to be nice enough devices, but they appear to be intended for vehicles that have fuel injection, along with all the associated sensors and computers.

I am sure that it would be possible to install on a GS, but would it really be worth it?

.

[pete]

Well, I think I see the answer in the second link:


They appear to be nice enough devices, but they appear to be intended for vehicles that have fuel injection, along with all the associated sensors and computers.

I am sure that it would be possible to install on a GS, but would it really be worth it?

.

There's an older version also that explicitly states it can be used for carbs as well as EFI, and Bosch for example have a bunch of different sensors available. From what I've found so far the kits simply operate off the voltage generated by the sensor, which is a lambda value of the difference between optimal AFR and the lean or rich state, which says to me it doesn't matter if it's carb or EFI.

http://www.bosch.com.au/content/language1/html/4566.htm

However, I'll definitely say something like this is very much on the "nice to have" list, and hence my initial question as to whether it really is worthwhile

My thought really is that it could help determine where in the throttle range the fuelling issue really is by combining the masking tape marks on the throttle and the LED bargraph, although it could get a little distracting while riding... a second one (for a twin) could be used to ensure both carbs are showing equal mixtures.

I'm more than likely overthinking again though

[Steve]

Especially with a TWIN, you are WAY overthinking.

I mean, your plug chops are twice as fast as the rest of us because you have half the plugs and carbs. ALL of your spark plugs are in the "outer" cylinder, meaning you don't have to reach across hot fins to pull the plug out.

I did not look real hard at those devices. Do they store data for later retreival? How do you correlate the throttle position with the data?

Do they show the data on a little monitor as you drive/ride? I would think that would be a LOT more distracting than making some marks on some tape, matching a couple of them, then riding for a minute or three at each setting.

.

[pete]

Hmmm... to be any use it would need to have a throttle position sensor and logging like you say...

Oh well, just a thought really...