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| techtalk:ref:carb07 [2024/11/12 05:24] – [Idle Mixture Screw - IMS - Aftermarket & Mods] hippysmack | techtalk:ref:carb07 [2024/11/12 07:03] (current) – [Idle Mixture Screw - IMS - Aftermarket & Mods] ixl2relax |
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| **CVP EZ-Just IMS**\\ | **CVP EZ-Just IMS**\\ |
| The EZ-Just mixture screw (for L76-87 or 88-06 models) ((https://cv-performance.com/ez-just-mixture-screw-81-87-harley-keihin)) ) can be purchased with an extended screw head for hand tuning. \\ You can buy packing from CVP also in case yours has been damaged or is not functioning properly. \\ But, check your local regulations before changing this out to an aftermarket part. \\ You can also find, buy or barter for used parts. \\ ("Please note: it is a violation of federal law to tamper with or disable any emission or noise control device. That is your PSA for the day"). ((XLForum member - chrishajer)) \\ | The EZ-Just mixture screw can be a handy upgrade. It allows you to get your fingers on the larger screw head rather than using a small screwdriver as required with the stock idle mixture screw. The EZ-Just is compatible for L76-87 or 88-06 version Keihin CV carbs.((https://cv-performance.com/ez-just-mixture-screw-81-87-harley-keihin)) |
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| The CVP screw taper has a longer and wider profile resulting in a different ratio per turn than the OEM screw. \\ | You can buy packing (spring, washer & o-ring) from CVP if your OEM parts have been damaged or are not functioning properly - BUT - Check your local regulations before changing IMS Settings or using aftermarket parts. **Please note:** "It is a violation of federal law to tamper with or disable any emission or noise control device. That is your PSA for the day."((XLForum member - chrishajer)) |
| This does not affect the operation of the screw. It may, however, slightly change the number of turns to get to the same location on the taper profile. \\ | |
| For those who depend on number of turns of the screw as a final setting, this is a bad idea. \\ | **Proper Screw Setting** - The taper of the CVP EZ-Just screw has a longer and wider profile versus the OEM screw. This results in a different fuel flow ratio per turn compared to the OEM screw. This still allows finding the right turns setting with the CVP EZ-Just, but it won't necessarily be the same number of turns as the OEM screw. |
| Any number of said turns out on the IMS screw, whether OEM or aftermarket, is only an initial setting, not a recommended setting. \\ | |
| It's best to let the engine tell you how many turns it needs instead of guessing or relying on a number of turns as a final setting. \\ | No one should simply pick a particular number of turns out from a light seat as a final setting. Picking a starting point is appropriate, but you really need to use the Idle Drop Method of tuning to find the right number of turns for the Idle Mixture Screw. Variations in the idle port orifice (due to wear or damage, etc.) along with variations in the different screws (OEM, CVP, Chinese aftermarket, etc.) makes it important to rely on the Idle Drop Method of tuning, rather than simply picking a number of turns. Any number of recommended turns out on the IMS screw, whether using OEM or aftermarket parts, is only an initial starting point and not specified as a final, properly tuned setting. |
| The best way to do that is to use the Idle Drop Method for a final setting on the IMS. \\ | |
| [[techtalk:evo:carb02#the_idle_drop_method_idm_for_setting_idle_fuel|Click Here]] for more informaton on this procedure from the CV carb tuning page in the Sportsterpedia. \\ | The final setting should always be based on the preference of the individual engine setup as found by the Idle Drop Method. |
| The pic below shows the taper dims from both the OEM and CVP IMS screw. \\ | |
| | [[techtalk:evo:carb02#the_idle_drop_method_idm_for_setting_idle_fuel|CLICK HERE]] for an explanation of the Idle Drop Method at the CV carb tuning page in the Sportsterpedia. |
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| | The pic below shows the taper dims from both the OEM and CVP IMS screw. Although different from each other, both are capable of reaching a proper adjustment of the fuel mixture for correct idle operation. |
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| {{:techtalk:ref:carb:ez-just_88-06_a-f_mixture_screw_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack, OEM dims by John Harper)) \\ | {{:techtalk:ref:carb:ez-just_88-06_a-f_mixture_screw_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack, OEM dims by John Harper)) \\ |
