Opening up exhaust flow for off-road use only - Page 2

Thumper · 02-06-2022, 03:27 PM

I just got a confirmation from AliExpress. The jets for my two piece pilot jet are "in the USA", and now there is ~50 day estimate on delivery. LOL!

(UPDATE: Ordered the pilot jets Jan 23rd, received them Feb 10th. Turns out that is just 19 days for shipping. Much better than I thought!)

But I did receive my main jets.

Whatever, I am happy to wait on the pilot circuit even though my pilot screw is out 4 turns!

Meanwhile, I checked the valves and they were tight, no gap/play at all

This is still at ~ 400km.
So I set them at snug 0.003" intake side and snug 0.005" exhaust side. Next size up 0.001 increment on both do not fit, and one size down loose fit. I removed the plug to make it easy to rotate the crankshaft for finding TDC mark, on compression stroke, and I saw slight greying. So it was on the lean side. Now the needle is shimmed and the pilot screw is another half turn out. I think it is still a bit too too lean so will get a larger main jet in there at least. That and the shim should fix low to midrange. I don't let the bike idle that much anyway, except when warming up on half choke

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Thumper · 02-14-2022, 11:51 PM

More work on the 2020Storm after opening up the exhaust...

I installed a #38 pilot jet, up from #34. This is a two piece pilot jet. The replacement was shorter (left), but it is under gas in the float bowl, so doesn't matter. Visual inspection and I can see the #38 is a slightly bigger jet.
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I set the pilot screw to 2 and a half turns and it started on half choke instantly, and happy off choke right away. Also, after off choke, it didn't choke/cough on throttle twist the way it used to (was lean on the needle, but shimmed ~2mm now). And this was cold! Good sign. Come onnnn Spring!

I also installed a #115 main jet while I had the carb out (pulled the #105 OEM main). No idea what that will do at top end, but weather is coming

I am going to try another ~mm on the needle shim after some test riding.

Oh, I have some extra #38 jets and an assortment as well if you need one. These two piece jets are easy to buy from AliExpress:

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02-06-2022, 03:27 PM	#16
Thumper Join Date: Feb 2021 Location: Kansas City Posts: 2,331	I just got a confirmation from AliExpress. The jets for my two piece pilot jet are "in the USA", and now there is ~50 day estimate on delivery. LOL! (UPDATE: Ordered the pilot jets Jan 23rd, received them Feb 10th. Turns out that is just 19 days for shipping. Much better than I thought!) But I did receive my main jets. Whatever, I am happy to wait on the pilot circuit even though my pilot screw is out 4 turns! Meanwhile, I checked the valves and they were tight, no gap/play at all This is still at ~ 400km. So I set them at snug 0.003" intake side and snug 0.005" exhaust side. Next size up 0.001 increment on both do not fit, and one size down loose fit. I removed the plug to make it easy to rotate the crankshaft for finding TDC mark, on compression stroke, and I saw slight greying. So it was on the lean side. Now the needle is shimmed and the pilot screw is another half turn out. I think it is still a bit too too lean so will get a larger main jet in there at least. That and the shim should fix low to midrange. I don't let the bike idle that much anyway, except when warming up on half choke Last edited by Thumper; 02-15-2022 at 10:28 AM.
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02-14-2022, 11:51 PM	#17
Thumper Join Date: Feb 2021 Location: Kansas City Posts: 2,331	More work on the 2020Storm after opening up the exhaust... I installed a #38 pilot jet, up from #34. This is a two piece pilot jet. The replacement was shorter (left), but it is under gas in the float bowl, so doesn't matter. Visual inspection and I can see the #38 is a slightly bigger jet. I set the pilot screw to 2 and a half turns and it started on half choke instantly, and happy off choke right away. Also, after off choke, it didn't choke/cough on throttle twist the way it used to (was lean on the needle, but shimmed ~2mm now). And this was cold! Good sign. Come onnnn Spring! I also installed a #115 main jet while I had the carb out (pulled the #105 OEM main). No idea what that will do at top end, but weather is coming I am going to try another ~mm on the needle shim after some test riding. Oh, I have some extra #38 jets and an assortment as well if you need one. These two piece jets are easy to buy from AliExpress: Last edited by Thumper; 02-15-2022 at 08:42 AM.
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