jalexquijano Posted February 13, 2018 Share Posted February 13, 2018 How do you set the .55 inches 9/16 measurement on the front and rear 3 screws su carb floats? Do you use a set of calipers? I need to know if the measurement is taken from the rim of the lid to the base of the float depressed or unpressed? Quote Link to comment Share on other sites More sharing options...
C.A.R. Posted February 13, 2018 Share Posted February 13, 2018 It's all described in the workshop manual. Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted February 14, 2018 Author Share Posted February 14, 2018 It's all described in the workshop manual. I watched the Ztherapy Just SU DVD and its not clear. I also reviewed the Haynes Manual and its not even explained precisely. Quote Link to comment Share on other sites More sharing options...
Administrators gav240z Posted February 14, 2018 Administrators Share Posted February 14, 2018 Couple of SU videos I uploaded to Youtube here. Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted February 17, 2018 Author Share Posted February 17, 2018 I would like to know if the .55 inch gap must be measured between the float valve lid bottom to the float valve as shown without depressing the pin on the needle valve. The video you uploaded deals with grose jets not neddle valves. Its really difficult to set the floats level this way. Quote Link to comment Share on other sites More sharing options...
1600dave Posted February 17, 2018 Share Posted February 17, 2018 (edited) Set it exactly like in Gav's 1st video from around the 26 minute mark. Set it with the lid upside down so the valve is closed by the weight of the float, don't use your fingers to push on the float to close the valve, you may push too hard causing the tab on the flaot to bend and get an incorrect reading. Grose jets are no different to needle valve as far as setting float height. Calipers are a bit fiddly to use, grab a 9/16" drill bit and use that, similar to the way the guy in the video uses block of the right thickness. Edited February 17, 2018 by 1600dave Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted February 17, 2018 Author Share Posted February 17, 2018 I though the measurement of 9/16 was taken with the float bottom just barely touching the valve stem and not pushing it down with its own weight. Quote Link to comment Share on other sites More sharing options...
1600dave Posted February 17, 2018 Share Posted February 17, 2018 It is taken with the valve closed by the weight of the float. You need the float to be in that position when the valve closes and shuts off fuel to the float chamber so that it keeps the level of fuel in the float chamber correct. To open another can of worms, to get it 100% perfect, you can ignore all that 9/16 float height setting stuff and set it by measuring the level of fuel in the jet, although I don't know what that setting is for 3 screw Hitachi SU's. Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted February 18, 2018 Author Share Posted February 18, 2018 Im posting some pictures to obtain your clarification if the 0.55 inch gap is taken from the bottom of the lid to the pin of the neddle valve not pressed by the weight of the float. Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted February 18, 2018 Author Share Posted February 18, 2018 Im posting some pictures to obtain your clarification if the 0.55 inch gap is taken from the bottom of the lid to the pin of the neddle valve not pressed by the weight of the float. Quote Link to comment Share on other sites More sharing options...
1600dave Posted February 18, 2018 Share Posted February 18, 2018 Yep. Don't forget to remove the gasket first. Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted February 19, 2018 Author Share Posted February 19, 2018 Do you have any video where this float level adjustment is explained? Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted February 20, 2018 Author Share Posted February 20, 2018 so it doesnt matter if the valve needle stem or pin is pushed by the weight of the float when measuring the 0.55 inch 9/16 gap? Quote Link to comment Share on other sites More sharing options...
1600dave Posted February 20, 2018 Share Posted February 20, 2018 Set it exactly like in Gav's 1st video from around the 26 minute mark. It is taken with the valve closed by the weight of the float. You need the float to be in that position when the valve closes and shuts off fuel to the float chamber so that it keeps the level of fuel in the float chamber correct. Quote Link to comment Share on other sites More sharing options...
d3c0y Posted February 20, 2018 Share Posted February 20, 2018 (edited) Lol Edited February 20, 2018 by d3c0y gav240z 1 Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted February 21, 2018 Author Share Posted February 21, 2018 Like this? I installed the longer needle and seat that goes on the 3 screws front carb float bowl and set the idle mixture screw to 2.5 turns clockwise. What next? Do i measure the fuel height with the pair of clear tubes connected to the drain plugs? Quote Link to comment Share on other sites More sharing options...
1600dave Posted February 21, 2018 Share Posted February 21, 2018 That's all you need to do, if you've set the float to correct height you're done. I can't vouch for specific settings for 3 screw carbs, never played with them.You did take the gasket off the float chamber lid to set float height ? Connecting clear tube to drain plugs isn't required assuming setting float height is done correctly. Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted February 28, 2018 Author Share Posted February 28, 2018 2 Questions: 1. Does the float needs to be parallel to the float lid when measuring the .55 inch gap or can it be bent or incline downward? 2. Is the measurement taken from the base of the lid to the bottom of the float or from the edge or rim or the float? Quote Link to comment Share on other sites More sharing options...
d3c0y Posted March 1, 2018 Share Posted March 1, 2018 Lol Quote Link to comment Share on other sites More sharing options...
TOO60Z Posted March 1, 2018 Share Posted March 1, 2018 Help me injected 2.8 you're my only hope. d3c0y 1 Quote Link to comment Share on other sites More sharing options...
Administrators gav240z Posted March 1, 2018 Administrators Share Posted March 1, 2018 2 Questions: 1. Does the float needs to be parallel to the float lid when measuring the .55 inch gap or can it be bent or incline downward? 2. Is the measurement taken from the base of the lid to the bottom of the float or from the edge or rim or the float? I think you're over thinking it. Quote Link to comment Share on other sites More sharing options...
1600dave Posted March 1, 2018 Share Posted March 1, 2018 (edited) 1. Nope, doesn't have to be parallel. Measure to roughly the centre of the float / across centre of float chamber lid, ie try to "average" it. 2. Usually gasket surface of lid to bottom (well, top...) of float. I haven't seen a 3 screw float up close and personal to be 100% sure of shape, but that's how you do it on British SU's. Really, you're talking a millimeter or two difference for the various methods of measuring you've suggested. Get it close enough and it will be fine, like the pic beow (ignore the fact that its a pommy carb, different float, different way to adjust float height and different sized rod used to set height). Edited March 1, 2018 by 1600dave Quote Link to comment Share on other sites More sharing options...
jalexquijano Posted March 1, 2018 Author Share Posted March 1, 2018 1. Nope, doesn't have to be parallel. Measure to roughly the centre of the float / across centre of float chamber lid, ie try to "average" it. 2. Usually gasket surface of lid to bottom (well, top...) of float. I haven't seen a 3 screw float up close and personal to be 100% sure of shape, but that's how you do it on British SU's. Really, you're talking a millimeter or two difference for the various methods of measuring you've suggested. Get it close enough and it will be fine, like the pic beow (ignore the fact that its a pommy carb, different float, different way to adjust float height and different sized rod used to set height). float.JPG Okay. So it doesnt matter if the gap is measured with the weight of the float closing the needle stem when the gap is .55 or 9/16 inch? Its really hard to accomplish this measurement blowing through the gas hole to keep the needle pin from depressing. I am using a wooden stick that measures .55 inches. Quote Link to comment Share on other sites More sharing options...
1600dave Posted March 2, 2018 Share Posted March 2, 2018 (edited) Its really hard to accomplish this measurement blowing through the gas hole to keep the needle pin from depressing.. Why would you want to do that ? Edited March 2, 2018 by 1600dave Quote Link to comment Share on other sites More sharing options...
Cozza Posted March 2, 2018 Share Posted March 2, 2018 Why would you want to do that ? Cause that’s what Trolls do. andyk_79 1 Quote Link to comment Share on other sites More sharing options...
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