06-17-2020, 09:59 AM | #1 |
Join Date: Jun 2016
Location: Arlington, VA
Posts: 258
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TT250 Keima Carb Numbers
I wanted to know what the dimensions on the stock TT250 Keima carb were in case I want to replace it. After measuring it, I believe these bikes come with such small carbs as a pollution measure. Smaller carbs run higher vacuum and carburate more cleanly. The numbers I was able to glean:
carb to manifold stud holes: 48mm center to center (no surprise here) carb exit to manifold ID: 29.5mm manifold intake ID: 30mm carb intake OD (snorkle i'face): 42mm Venturi: 21mm by 28mm It is the last number I find most distressing. An Aermacchi 250. An Italiam 250 pushrod single from the 60's had a 28mm round bore carb stock. I find it hard to believe that a stock 229cc CG motor could not have decent drivability and a better top end with nothing less than a 28mm smooth round bore carb. Right now the only carbs I see out there that look promising are the PWKs that all have the power jet attachment. Does anyone know if they are round bore or oval bore?
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4 time WERA SuperVintage Roadracing National Champion, SCTA Land Speed Record Holder, 3rd AMA Motorcycle GP of Miami Last edited by mtiberio; 06-17-2020 at 10:30 AM. |
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06-17-2020, 10:05 AM | #2 | |
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Quote:
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2024 Linhai 300 ATV 4x4 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel |
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06-17-2020, 12:04 PM | #3 | |
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Quote:
Also i found the PE28 much easier to jet than the PWK. |
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06-17-2020, 12:57 PM | #4 |
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PE28 is an oval bore? Max venturi width, what? 26? With a choke plate to eff up the flow? No thanks
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4 time WERA SuperVintage Roadracing National Champion, SCTA Land Speed Record Holder, 3rd AMA Motorcycle GP of Miami |
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06-17-2020, 01:07 PM | #5 |
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The PE is a round smooth bore just like the PWK. The difference is the PWK has a flat slide and the PE has a round slide.
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2024 Linhai 300 ATV 4x4 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel |
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06-17-2020, 04:21 PM | #6 | |
Join Date: Dec 2016
Location: Argentina
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Quote:
The ones with a choke plate are the PD and the PZ(clones of the PD) The PE are mostly a PWK but with a round slide and no power jet. Plus you have the PE30 with has a bigger venturi. |
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06-17-2020, 06:44 PM | #7 |
Join Date: Jun 2016
Location: Arlington, VA
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Good stuff, thanks. I ran PWKs on my Guzzi, so i'm familiar. The powerjet can always be defeated.
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4 time WERA SuperVintage Roadracing National Champion, SCTA Land Speed Record Holder, 3rd AMA Motorcycle GP of Miami |
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06-17-2020, 08:18 PM | #8 |
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Location: Argentina
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Yes of course that the powerjet can be disable.
I love PWK, so i tested them on various CGs (125 to 229), i like them a lot they performance great from 1/4 to WOT but they always seems to struggle at idle, no matter what pilot jet i use. So i did got a PE, they idle just fine but yes the PWK fells much better at near wot. |
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