Carb Setup on Dyno | GTAMotorcycle.com

Carb Setup on Dyno

Clem

Well-known member
So I'm finally getting close to finishing up my GPZ (pictures to follow). I'm running a set of 26mm Keihin CR Specials and a Wolf 4:1 pipe (Gary Wolf from Guelph/Waterloo area) so it has that period look and sound but its definitely running rich.

I was wondering if someone in the GTA still sets up carbs on a dyno although I know it may be a bit of a dying art in the age of the ECU's.

Winners Circle have all the jets and needles in stock.

Thanks in advance.
 
So I'm finally getting close to finishing up my GPZ (pictures to follow). I'm running a set of 26mm Keihin CR Specials and a Wolf 4:1 pipe (Gary Wolf from Guelph/Waterloo area) so it has that period look and sound but its definitely running rich.

I was wondering if someone in the GTA still sets up carbs on a dyno although I know it may be a bit of a dying art in the age of the ECU's.

Winners Circle have all the jets and needles in stock.

Thanks in advance.

Not exactly what you are asking for but I bought a wideband O2 to tune toys with. You can catch lots of things with it that I would be surprised if the dyno operator spent much (or any) time on (eg. part load operation, A/F ratio when snapping the throttle open, etc.). If you didn't want to put a bung in your exhaust, you can jam the sensor into the muffler and get a decent reading as long as it is deep enough.
 
Not exactly what you are asking for but I bought a wideband O2 to tune toys with. You can catch lots of things with it that I would be surprised if the dyno operator spent much (or any) time on (eg. part load operation, A/F ratio when snapping the throttle open, etc.). If you didn't want to put a bung in your exhaust, you can jam the sensor into the muffler and get a decent reading as long as it is deep enough.

Interesting. What and where did you buy it. I'm not too far down the road to weld a bung in but putting the sensor down the muffler may work.
 
If you want to travel , I'm sure Scott Miller (fast company) in Kitchener could get it set up for you .
 
GreyGhost has a great idea. Buy it once and profit for a lifetime, although you potentially have some welding to do. There are some great videos online showing how to use it

I've had Sandy at Pro6 dyno some stuff for me, Zed at Z1 (Are they still in business, someone told me they were gone which would be a huge shame) and Ken Livingstone (I don't know if he took the Dyno with him when he opened up his own new shop). I've been pleased with all three.

I've also heard that Ace Moto Tech are good but personally I have never used them.
 
I bought an Innovate XD-16 based mostly on the article below. It is amazing how poorly most of the gauges did (to the point of being worse then useless as they were giving bad/very delayed data). They are expensive toys, but work quite well. If I was buying now, I would redo the research as maybe something newer and better is out there.

http://www.diyautotune.com/downloads/Wideband Shootout.pdf

If you decide to put in a bung, the 02 sensor likes to have some slope to it so any possible condensate doesn't settle in it. That limits your placement options.

If you really wanted to see what was happening, you could put one bung in each header and one in the collector. You move the sensor around to set it up and then leave it in the collector to monitor. Unless you are going for the edge of performance, I don't know if this would be a worthwhile experiment or not (how many times do you want to pull the carb rack to fine-tune the centre carbs?).
 
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I have a AEM a/f gauge on my bike, took all the guess work on jetting the carbs

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That's the newer version of mine. Damned have the prices ever come down a lot. Amazon reviews for the particular one aren't glowing.

Yep they are not good, all because of the sensor. The sensors seem to fail a lot for people who use it as a permanent setup all the time. I know a few guys who use them just for tuning and then plug the bung and they are all good.
 
I dont know about that johnnnw, I have a bosch 02 sensor in my bike that has at least 40k on it and it works the same as it did the day I installed, they will last 100s of thousand kilometers in a automoble, whats the difference ? why wont they last on a bike
 
I dont know about that johnnnw, I have a bosch 02 sensor in my bike that has at least 40k on it and it works the same as it did the day I installed, they will last 100s of thousand kilometers in a automoble, whats the difference ? why wont they last on a bike

I meant the one in the link I posted. It's only good for very little use is what I'm told by someone who has that exact one. I am also in the market for a wideband, and looked at that one yesterday so this thread was good timing. I did not buy it due to the reviews, still looking.
 
I dont know about that johnnnw, I have a bosch 02 sensor in my bike that has at least 40k on it and it works the same as it did the day I installed, they will last 100s of thousand kilometers in a automoble, whats the difference ? why wont they last on a bike

I think the ones factory installed in cars are an entirely different animal as they aren't wideband sensors. The wideband has been in my mini for years with no problems. I wonder if the people with problems were installing them improperly?
 
OEM lambda sensors are carefully positioned and the heater is controlled to keep it in an optimum temperature range. Aftermarket ones ... might not be. I suspect that temperature too low (too far down the exhaust pipe) + constant rich operation will foul them.

Lots of cars use wideband sensors nowadays. They essentially never leave closed-loop control.
 
OEM lambda sensors are carefully positioned and the heater is controlled to keep it in an optimum temperature range. Aftermarket ones ... might not be. I suspect that temperature too low (too far down the exhaust pipe) + constant rich operation will foul them.

Lots of cars use wideband sensors nowadays. They essentially never leave closed-loop control.

Thx Brian.
 
For a bike I would lean towards the one Ronnie used without buttons (unless specs show that the buttoned one is watertight). Water will run down the face, follow the button stalks and kill the gauge.

Good point on the buttons, I'm not sure on the particulars of his set up though, all he has shown is the gauge.
 
So I took GreyGhost's advice and bought a Wideband 02 sensor and gauge. I ended up with a AEM 30-4110 based on the reviews it got. I also bit the bullet and had a bung welded into the exhaust right at the collector.

It definitely simplifies things a great deal and the initial settings were all over the place. At idle it was about 10:1, midrange (1/4 - 3/4) was about 12:1 and up top it dropped to about 16:1.

It took me about an hour. The nice thing with the CR's is that you can take out the jets (with the exception of the pilots) and the needles without taking the carbs of the bike

Its now running between 13.8-14.2 across the range and its a pleasure to ride. Still a little rich and I guess I could try to get the curve a little flatter but I'm pleased with it for now.

I also bought a plug for the bung so I'll leave it on for a few weeks and if everything still looks good I'll probably remove it and just stick the plug in.

Thanks GreyGhost. I owe you a pint.
 
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So I took GreyGhost's advice and bought a Wideband 02 sensor and gauge. I ended up with a AEM 30-4110 based on the reviews it got. I also bit the bullet and had a bung welded into the exhaust right at the collector.

It definitely simplifies things a great deal and the initial settings were all over the place. At idle it was about 10:1, midrange (1/4 - 3/4) was about 12:1 and up top it dropped to about 16:1.

It took me about an hour. The nice thing with the CR's is that you can take out the jets (with the exception of the pilots) and the needles without taking the carbs of the bike

Its now running between 13.8-14.2 across the range and its a pleasure to ride. Still a little rich and I guess I could try to get the curve a little flatter but I'm pleased with it for now.

I also bought a plug for the bung so I'll leave it on for a few weeks and if everything still looks good I'll probably remove it and just stick the plug in.

Thanks GreyGhost. I owe you a pint.

Regarding your final numbers that isn't a little rich at all, depending on where you mean. At WOT you actually want to be richer (around 12.5-13) for the most power. You don't always want 14.7.
 

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