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01-10-2017, 06:24 AM | #1 |
Join Date: Dec 2016
Location: Rochester, NY
Posts: 28
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Why a Mikuni Carb for Hawk?
I know one of everyone's favorite mods for the Hawk 250 is a Mikuni Carb. But no one ever seems to explain why? Why is it better than the stock carb and why does it give the bike more power? Thanks!
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01-10-2017, 06:36 AM | #2 |
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Join Date: Oct 2016
Location: Houma, La.
Posts: 11,593
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That's a good question. I just used the stock carb and change the jet. I would like to know too if there was a big difference. Has anyone tried both to see the difference.
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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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01-10-2017, 07:37 AM | #4 |
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Join Date: Oct 2016
Location: Houma, La.
Posts: 11,593
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I wouldn't grind the slots either. A fine tooth hacksaw is a lot safer and does a cleaner job. takes less than 5 minutes to do. As far as the two carburetors, is there any difference between the two?
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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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01-10-2017, 07:45 AM | #5 |
Join Date: Jun 2011
Posts: 1,335
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If I'm not mistaken, the throat on the Mikuni is a little larger and flows a little better on top end.
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01-10-2017, 10:14 AM | #6 |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,054
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You get better top end flow, and the jets for mikunis are far more readily available locally...not to mention some of the keihin clone carbs used funky non keihin sized jets to make it even more coomplicated... you can go to any powersports store and get mikuni jets...
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01-10-2017, 10:28 AM | #7 | |
Join Date: Mar 2010
Location: Volcano, Ca
Posts: 7,105
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Quote:
The other upside is you can do as many or as few mods as you want, and keep the bike breathing properly with the available Mikuni jetting. That said, my neighbor is perfectly happy with how his new TT250 runs with the stock setup....but we're at 3000'. These CB's have a tendency to come horribly lean.
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"Light a fire for a man, and you heat him for a day. Light a man on fire, and you heat him for the rest of his life." 2007 Suzuki DRZ400S (SM convert) 2009 Q Link XP 200 1967 BSA B25 250cc Starfire 2022 Royal Enfield Interceptor 650 2023 Royal Enfield Scram 411 1948 Royal Enfield Model G 350 |
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01-10-2017, 02:14 PM | #8 | |
Join Date: May 2006
Location: Yuma, Arizona
Posts: 9,035
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Quote:
Off subject, but getting to the point--those riders who passed high elevation passes reported how great their 150cc (sometimes larger--i.e. 200cc Zongshen enduro that Spud made famous--i forget the model but it was popular as well) did on the passes; not to mention how great the engines performed overall at all elevations. But, yes, they were lean from the factory. OK, memory lane over--back on topic...
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"They say that life's a carousel, spinning fast you got to ride it well..." TGB Delivery Scooter 150 TMEC 200 Enduro--carcass is sadly rotting in the backyard |
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01-11-2017, 01:51 AM | #9 |
Join Date: Mar 2008
Posts: 2,436
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Good old days ≠ Today's blended gasohol / Environmental here & there
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01-10-2017, 12:40 PM | #10 |
Join Date: Oct 2015
Posts: 75
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It seems like main jets are regularly available for the PZ30, but I have not heard of anyone having a definitive source for the pilot jets that will fit that carb.
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01-10-2017, 02:31 PM | #11 | |
Join Date: Jun 2016
Location: akwesasne, NY-13655
Posts: 2,220
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Quote:
You can make the PZ carb work from 1/2 throttle and up, but without replacing the pilot jet and (some times) the throttle cut-away, low end is either soggy, or just something you go through to get to 1/2 throttle, and above. If you ride 90% on road, the PZ will do all right. Off road requires much better low end carburation. Now, if you've never ridden a bike with a good carburetor, like an Amal, or a Del'Orto, or a Mikuni, you won't know what you are missing. Even electronic fuel injection can't match what one of those carbs can do without re-mapping. A very expensive process. EFI is used mainly for emissions compliance. If you are worried about exhaust emissions from a vehicle that gets 80-100 miles per gallon, well, switch to efi. |
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01-10-2017, 08:40 PM | #12 |
Join Date: Jun 2011
Posts: 1,335
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This is just my experience with similar bikes with carbs vs efi. I'm not trying to get anyone worked up.
I have a CB500X and it runs rich with the EFI system from the factory.Member McRat on advrider did a lot of testing from OE and using various exhaust systems and air filter set ups. If I'm not mistaken he also tried a a fuel management unit as well. All was dyno'd. I was surprised by his findings. I have a GS500, that I did a lot of air intake and exhuast work to, and it has dual 33mm Mikuni carbs. In good tune, it will beat the pants off my CB500X hands down. The CB500X has dual 34mm throttle body injection. The specs from factory shows that the CB500X should be more powerful than the GS500. I can verify that even a stock GS500 will run down a stock CB500X. I think it lies in three areas, the GS is 30lbs lighter than the CB. Plus the GS has an 11,000 rpm redline, where the CB has a 9500 redline. Also, the GS is tuned for mid and top end similar to a sport bike. The CB is tuned mostly for low to mid-range similar to and enduro. The CB is a water cooled engine and the GS is an air cooled engine. I know the GS runs hotter. To some extent, comparing the CB and GS is like comparing apples to oranges. I agree with Ariel Red Hunter on tuned carbs providing more power than OE EFI set ups, when comparing the same motorcycles. However, a properly tuned EFI can be way more powerful than carbs, because it can more precisely meter fuel through out the rpm range. There's not many people willing to spend the kind of money it takes to actually tune an EFI motorcycle properly. I was quoted $1300 to properly tune my CB500X, on a dyno, from Pro Boys Toys. Not worth it. The CB500X cost me $5400 OTD brand new. Those that think programmers and fuel management controls are tuning EFI, they are not. They simply fool the OE engine management into providing more fuel at preset RPMs. Some of the more expensive units can handle small changes in ignition timing. All of this is preset in the unit, and to some extent, it can be changed. It's not at all like someone dialing in a bikes EFI and ignition, through out the engines entire rev range, while running it on a dyno. If you're really interested in this kind of stuff, I urge you to do the research. It's very interesting. |
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01-11-2017, 06:17 AM | #13 | |
Join Date: Jun 2016
Location: akwesasne, NY-13655
Posts: 2,220
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Quote:
Last edited by Ariel Red Hunter; 01-11-2017 at 06:56 PM. Reason: I thought of something else |
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01-11-2017, 08:03 AM | #14 |
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Join Date: Oct 2016
Location: Houma, La.
Posts: 11,593
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side by side comparision
Here's a side by side comparison by TheGageinator http://chinariders.net/showpost.php?...20&postcount=1 Looks like the inlet and outlet are slightly larger. I'm just curious if anyone has done a comparison between the two. How much more power?
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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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