Basic carb setting guide

[Lowspot]

Since there has been some questions about carb settings lately, I figured it was about time to post something up to help people out. Keep in mind that these settings are just a starting point, they will vary depending on where you live (elevation, climate, temperature, humidity, engine displacement, different pipes, air filter, ect.) there will be a need to fine tune after these setting are done for greatest performance. You will also need to set the idle to your own taste using the idle screw (no more using the low speed screw for idle).

Settings for WA-167, WT-603, WT-668, WT-990 carbs (these being the most popular)

Low speed jet 1 1/4
High speed jet 1 1/2


WT-813 (this carb is the same as the WT-990 but it has an internal accelerator pump requiring it to use different settings)

Low speed jet 1
High speed jet 1 1/4

HDA-223 (GP 460 carb)

Low speed jet 1 1/2
High speed jet 1 3/4

All settings are tuned out from lightly seated, seated meaning screwing the jet in until it stops (do not force it, you will damage the seat/jet)

This is only a guide, it is up to the operator to check and make sure all the gaskets and pulse holes line up right and that all the engine bolts are tight, because air leaks can screw up these settings and make tuning a nightmare.

Fine tuning is the turning of the jet in small degrees in either direction to achieve the desired effect.

To richen the mixture, you will turn the jet out (counter clockwise)
To lean the mixture, you will turn the jet in (clockwise)
This is the same on all carbs for the Hi and Low speed jets

I haven't dealt with the adjustable WYK carbs that much (I only have one on a 40) so if anyone else would like to chime in on the setting on those carbs, feel free to do so.

I hope this helps some people out.

Carb ID can be done by finding the numbers on the side of the carb near the fuel inlet.

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[hondaboi]

Sticky!!!

[Pushinit]

77b

Low Jet 1 3/4
High Jet 1

[Lowspot]

I left the HDA48 and 77B carbs out of this list because they are used mostly on 60s and very seldom on 46s, there is more work to get them to work correctly on a 46 than most Pedders are going to want to mess with. the guide is for basic stockish engines/carbs that one would get off the shelf. Jumping to a 60 is a world all to its own and would deserve a thread just for 60s.

[Pushinit]

People will late ask what is a good carb for a reeded motor. And a 77b works very good on a reed 460 just incase you want to make a reeded carb adjustment category. But yes 77b sucks on a stock 460.

[Lowspot]

Yeah but 60s and reeds are not what this thread is about, this thread is about the carb tuning issues the normal everyday Pedder is going to run into and give them a base to start from.

[Z46C]

First you have to make sure your metering lever height is on point. If it's too low you'll have bad throttle response. Most people won't be able to tell the difference but if you have like a 603/668 on a built/piped rc with a thin gasket then you will notice if your metering lever is off. I've had em extremely low from the factory. (Only on the hda series though). Really gotta understand the whole entire thing to do it spot on but to get by read plugs and learn how lean/rich sounds

[Lowspot]

.

[Troy sr]

First you have to make sure your metering lever height is on point. If it's too low you'll have bad throttle response. Most people won't be able to tell the difference but if you have like a 603/668 on a built/piped rc with a thin gasket then you will notice if your metering lever is off. I've had em extremely low from the factory. (Only on the hda series though). Really gotta understand the whole entire thing to do it spot on but to get by read plugs and learn how lean/rich sounds

How would you adjust that? I have a off ideal lean spot on my 223 that I have to run rich on l screw to over come, .. Reeded 40

[Lowspot]

How would you adjust that? I have a off ideal lean spot on my 223 that I have to run rich on l screw to over come, .. Reeded 40

What settings are you running the carb?

[Troy sr]

What settings are you running the carb?

2L 1.5H seem like I gota blip it a few times to load with fiel

[Lowspot]

Wow that is way rich on the low jet, is the carb new or does it have a lot of time on it? At the stock 460 setting that sarb should be drowning that engine.

[Troy sr]

Wow that is way rich on the low jet, is the carb new or does it have a lot of time on it? At the stock 460 setting that sarb should be drowning that engine.

It's new, just got today, I get the lean bog at 1.25... Pulse line is from reed case to carb opposit side of carb

[Guest]

Switch that around. 1.5L and 2 H

[Guest]

Oh ya and make sure the phillips idle screw is almost all the way out barely touching