MOPED ARMY

Well, for starters, the exact idle rpm would be a function of the carb choice to a certain degree, don't sweat that, set the idle high enough that it won't die and low enough that it won't grab the clutch.

As far as the slides go, you already have them so try them and see. Inside the carb there is a emulsion tube that runs vertical with holes in it, the different slide shapes are trying to reduce vacuum (increase pressure) on that tube by slowing down the air velocity at 0-30% throttle give or take. Reducing the vacuum causes less fuel to flow.

Based on your temps it sounds like you're already tuned pretty well, at low load the temp will definitely drop. Head Temp isn't really a good tuning tool the way you're talking about it here, it's only a warning light duty something being way wrong.

Its a trail tech from treats with the spark plug washer

61 seems like a small jet for your setup. I would think 70-75. You don’t seem to be at altitude.

I would try slide 6 or 7 and see what that does for your idle and low end. (edited)

Ill give that a shot tomorrow, got 12hr shift today. But i was thinking the same thing about the jet but i kept going down so it wouldn't 4 stroke at lower temps. Now that i think about it, it makes sense my engine wont hold the heat at 1/4 thottle if the slide is letting in too much gas to begin with but when frustrated you dont think logically

Most people understand the concept of jetting. To me it seems these carbs arent popular as upgrades cause theres not to many threads about tuning the low end so they get overlooked or skipped . Im willing to put in the time to figure out how to get it running optimally. When i post on reddit it seems no one is aware of how slide effects performance which makes sense because when they come stock on bikes like a tomos theres no need to fiddle with slides because the manufacturer took care of that beforehand

so ok, a #2 slide and #9 slide have the same cutaways. the #9 is just physically shorter and clears the whole venturi on the larger bore SHA carbs (14:14-16:16)

a #1 slide and a #10 slide have the same cutaways and the #10 is physically shorter and clears the whole venturi too, but is not available really anywhere.

i’ve modified #7 slides to the same cutaway as a #1 slide and it opens the full way and is a good stand in for a #10 slide.

having the carb open the whole way is super important to getting the carb to settle back to idle nice and smoothly.

number 9 slide

number 2 slide

They make an offset woodruff key for the pw50 that will work. Depending on how you install it, it will advance or retard timing about 3.5 degrees (relying on memory here as to timing degree change)

That's good to know about I only assumed that the CDI was the only option for QT50s. What would the benefit of changing my timing be in this situation? Seems drastic at this point in time

Get Tom's slide. Sha game changer. Seriously. Adam, get one from him. My Sha has never felt so alive!

@OP: Sha carbs are not tuned the same way other carbs that contain multiple jets for controlling different throttle positions and have needles with tapers. The only thing that controls everything is the slide. The issue with the low end is the lack of adequate fuel and air due to the majority of the vinturi being blocked by the slide. Tom's slide helps with this by having some boost windows in the wall of the slide. You can make your own with a very fine drill bit, or grab one from Tom. I also tried the 3d printed one, but it was not as easy to tune.

The benefit of this style of slide was that it allowed me to make sure I was jetted properly for the top end but did not bog out my low-end. It let me go up a couple jet sizes as well.

The other important thing on Sha tuning is their screen pack. It is important. But you can remove screens to find just the right mix of air. The only other filter that will work if you want to ditch the screen pack is a good foam filter. But too dense of foam and it will never get enough air. The mesh screen filters do not offer enough air restriction on their own so you still need to run the screen pack.

Lastly. Shas have an air leak at their clamp you must have an o-ring behind the shim that goes into your intake. The o-ring is the only way to stop that air leak.

Hey tom, could you post a photo of that slide sids by side with a #1, I have a bunch of #1s so that'd be the side I'm most comfortable trying to modify

The with the #9 the clutch catches before i can turn down the idle enough before stalling so im gonna give #7 a go

In a side note, this is opposite to my previous issue where i had #2 slide and 60 jet the clutch would not engage untill a very high idle

Welp nevermind.... I guess I must have ruined the slide or something. I had it almost perfect and I'm just so pissed off right now. After filing it down I started 4 stroking again so I went And tried my jets all the way down to 58 so now I am bogging and then 4 strokeing. I am just at a loss I was so close just should left the damn thing alone. I am done for the day. I guess I'm just going to order another #6 slide and just leave it the fuck alone. Fuck

I know i have 3, possibly 4. Are you selling your casted slides? Definitely seems like its worth a try. I did go ahead and order the 3D printed one with the #6 from treats but ill to bet yours will operate better. Ive got venmo and zelle

Also, everything that Graham said is exactly what you need to know for planning to modify your own slide. And I think that is what times design did best was have the way for the air to push past the emulsion tube at lower throttle positions. Just mark some holes to the edge of the slide that you can visibly see in the carb when it is all the way down. Make one on each side at one of the lowest spots you can see. I will see if I can get some pics of how Tom's slide looks at rest.