SH2/22 SETUP

Check here for a list of various carb set-ups to help with jetting and all aspects of carb trickery!
Rodders1964
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Wed Jul 26, 2017 11:33 pm

Hi,

I have an LI125 S3 with a 42mm clubman exhaust.
I've recently fitted a gp150 inlet manifold and a Scootopia SH2/22 carb.
Can anyone tell me which jets and other parts I should be using? I'm struggling to get her going properly.

Many thanks
Joe

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rosscla
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Thu Jul 27, 2017 9:56 am

The Scootopia carb is supposed to be supplied with both the the 150 and 200 slide, I'd also expect you should get the appropriate atomisers and jets for the standard out of the box config.

GP150 should be 7895-2 slide and 5899-4 atomiser with 118 main, 45 pilot and 50 choke
GP200 should be 7895-1 slide and 5899-2 atomiser with the other jets the same

I'd expect either of these set ups to be way too rich for your 125 and you'll struggle to start it. Try taking the air hose off and see if it runs / starts any better.

If it does then you need to drop either the pilot or the main or both. I'd suggest stick with the 150 slide atomiser combo and start somewhere around 110 main and keep going down from there till it starts and runs clean. You may struggle to find pilot jets smaller than the 45. You can get a set or individual jets here -

http://www.kmtproducts.co.uk/index.php? ... egory_id=9

I've just been through something like this with my Lince. It originally had a SH1/20 but when I rebuilt it I used an SH2/22 which I jetted with 45 pilot, 50 choke and 124 main similar to the late Indian GP200, since I had also fitted a big bore pipe. It would not fire with the air hose on. With it off it would pop once or twice but not catch. I swapped the pilot to a 50 and it actually started but was very boggy and unwilling to rev. Taking the air hose off it would rev much more cleanly. I dropped the main to 118 and it starts first / second kick with the air hose on and revs much better. I think there's still a bit more refinement to be had, maybe a 48 pilot.

Good luck
"Our dilemma is that we hate change and love it at the same time; what we really want is for things to remain the same but get better."

Daggs
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Thu Jul 27, 2017 1:19 pm

You gave some good advice there Rosscla. Until you said

" I dropped the main to 118 and it starts first / second kick with the air hose on and revs much better"

The Main jet has no impact on starting.

Muppet
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Thu Jul 27, 2017 1:43 pm

the fuel to the pilot jet has to travel through the main jet first; the fuel supply to the pilot is from the main jet on an sh2/22; i was educated to that fact by a very wise man
C’est la vie

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rosscla
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Thu Jul 27, 2017 4:25 pm

It's what I found, I can't explain why but it felt like it was flooding. Soon as I took the air hose off it tried to fire which lead me to the conclusion it wasn't getting enough air in the mix or too much fuel...

If what Muppet says is correct, and I have no reason to doubt it, that would make sense, the pilot in the SH carbs only has holes in the tip so the fuel must get there somehow?

An adult may explain the fuel flow or produce some evidence shortly.
"Our dilemma is that we hate change and love it at the same time; what we really want is for things to remain the same but get better."

Rodders1964
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Thu Jul 27, 2017 7:34 pm

That is for the link and advice. I'll have to do a bit more messing until I get it right, I suppose. I asked Scootopia what they thinkbi should use and he said try a main jet around 124 and change the slide. Sounds too high to me.

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Rodders1964
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Thu Jul 27, 2017 7:35 pm


Rodders1964 wrote:Thanks for the link and advice. I'll have to do a bit more messing until I get it right, I suppose. I asked Scootopia what they thinkbi should use and he said try a main jet around 124 and change the slide. Sounds too high to me.

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Rodders1964
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Posts: 10
Joined: Sat Jul 22, 2017 12:58 pm
ebay user ID: Redbigrod
Main scooter: LI125 Series 3
Contact:

Thu Jul 27, 2017 8:14 pm

rosscla wrote:The Scootopia carb is supposed to be supplied with both the the 150 and 200 slide, I'd also expect you should get the appropriate atomisers and jets for the standard out of the box config.

GP150 should be 7895-2 slide and 5899-4 atomiser with 118 main, 45 pilot and 50 choke
GP200 should be 7895-1 slide and 5899-2 atomiser with the other jets the same

I'd expect either of these set ups to be way too rich for your 125 and you'll struggle to start it. Try taking the air hose off and see if it runs / starts any better.

If it does then you need to drop either the pilot or the main or both. I'd suggest stick with the 150 slide atomiser combo and start somewhere around 110 main and keep going down from there till it starts and runs clean. You may struggle to find pilot jets smaller than the 45. You can get a set or individual jets here -

http://www.kmtproducts.co.uk/index.php? ... egory_id=9

I've just been through something like this with my Lince. It originally had a SH1/20 but when I rebuilt it I used an SH2/22 which I jetted with 45 pilot, 50 choke and 124 main similar to the late Indian GP200, since I had also fitted a big bore pipe. It would not fire with the air hose on. With it off it would pop once or twice but not catch. I swapped the pilot to a 50 and it actually started but was very boggy and unwilling to rev. Taking the air hose off it would rev much more cleanly. I dropped the main to 118 and it starts first / second kick with the air hose on and revs much better. I think there's still a bit more refinement to be had, maybe a 48 pilot.

Good luck
I did set it up as the original SH1/18 carb but it didn't work at all. That was a 42 pilot, 50 choke and 99 main.
I'll just keep messing with it. I'll probably get a box of jets from the link you suggested. Thanks for that.
It's really frustrating, I just want to get out on it.

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