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techtalk:ih:engmech09p [2021/05/30 02:01] – [1957-1976 Top Center Motor Mount, 1977-1979 Head Strap] hippysmacktechtalk:ih:engmech09p [2023/12/27 21:18] (current) – hippysmack
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 [[:techtalk:menu|{{  :techtalk:gototechnicalmenu.jpg|}}]] [[:techtalk:menu|{{  :techtalk:gototechnicalmenu.jpg|}}]]
 ====== IH: Engine Mechanicals - Sub-09P ====== ====== IH: Engine Mechanicals - Sub-09P ======
-====== Problems with Illustrations in the HD Manuals for 1957-1978 Head Straddle / Strap Mounts ======+====== Discrepancies with Motor Mount Illustrations in the HD Manuals (57-76) ======
 \\ \\
-====== 1957-1976 Top Center Motor Mount, 1977-1979 Head Strap ======+====== Center Mount Straddle Bracket ======
 This section is dedicated to the assembly positioning of the 1/8" washers during assembly for the top motor mount straddle on 1957-1976 models. \\ This section is dedicated to the assembly positioning of the 1/8" washers during assembly for the top motor mount straddle on 1957-1976 models. \\
 This also includes the 77-78 "head strap" between the heads (but does not tie back to the frame). \\ This also includes the 77-78 "head strap" between the heads (but does not tie back to the frame). \\
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 **CAN YOU ASSEMBLE THE WASHERS ON TOP OF THE STRADDLE MOUNT**? \\ **CAN YOU ASSEMBLE THE WASHERS ON TOP OF THE STRADDLE MOUNT**? \\
 Of course you can. There are many, many Ironheads running around right now with them on top. \\ Of course you can. There are many, many Ironheads running around right now with them on top. \\
-You may have to fine tune the position of the cylinders or run a rat tail file in the straddle holes to gain some clearance. \\ +You may have to run a rat tail file in the straddle holes to gain some clearance or even grind some off the straddle itself. \\ 
-And repositioning the cylinders may throw out the connection at the intake manifold and create an air leak. \\+Placing the washer on top of the mount also decreases the height of the straddle which adds more space between the cross brace and frame mount. \\ 
 +So you'll need more spacers there to make up that difference. \\ 
 +The intake manifold fit determines head and cylinder position. ((ryder rick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/189737-top-motor-mount-bracket-hole-mis-alignment?threadid=2023240)) It's a bad idea to turn the cylinders just to make the mount work. \\ 
 +This is critical on an O-ring style joints. Too big of a gap and the O-rings may not seal correctly and create an air leak. \\
 But all in all, it can be done while paying close attention to the assembly process. \\ But all in all, it can be done while paying close attention to the assembly process. \\
 +
 **However, due to the possibility of cracking the head at the tapped holes for the straddle mount if it doesn't line up correctly**; \\ **However, due to the possibility of cracking the head at the tapped holes for the straddle mount if it doesn't line up correctly**; \\
 [[techtalk:ih:engmech09#factory_top_mount_installation_per_dr_dick|Click Here]] to reference **Factory Top Mount Installation per Dr Dick** on the main Ironhead motor mount page of the Sportsterpedia. \\ [[techtalk:ih:engmech09#factory_top_mount_installation_per_dr_dick|Click Here]] to reference **Factory Top Mount Installation per Dr Dick** on the main Ironhead motor mount page of the Sportsterpedia. \\
 +Swapping the washers around to the bottom of the straddle is a lot less painful or concerning. \\
 You may find that the holes line up better which puts less stress on the motor. \\ You may find that the holes line up better which puts less stress on the motor. \\
 And there shouldn't be any added stress to the motor when tightened down to the frame. \\ And there shouldn't be any added stress to the motor when tightened down to the frame. \\
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 In fact, you can induce added vibration and potential for cracks in the mounts or cases if the mounts aren't installed properly. \\ In fact, you can induce added vibration and potential for cracks in the mounts or cases if the mounts aren't installed properly. \\
  
-|Washers on top of the straddle mount (71 XLCH). \\ (as shown in the parts books and most FSMs) ((photo by piniongear of the XLFORUM http://xlforum.net/forums/showthread.php?t=1139862&page=3))|  Machined area on head for the straddle mount. \\ (notice the binding that occurred in the left pic) ((combined pics from Ebay sellers, Vintage Parts Suppliers, [[https://www.ebay.com/str/vintagepartssuppliers?_trksid=p2047675.l2563|Link to Ebay Store]] and Rusty Dusty Motorcycle Parts [[https://www.ebay.com/str/bialystreasures?_trksid=p2047675.l2563|Link to Ebay Store]] ))|  +|Washers on top of the straddle mount (71 XLCH). \\ (as shown in the parts books and most FSMs) ((photo by piniongear of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/117858-wiring-placement-pictures-or-diagrams/page3?t=1139862&page=3))|  Machined area on head for the straddle mount. \\ (notice the binding that occurred in the left pic) ((combined pics from Ebay sellers, Vintage Parts Suppliers, [[https://www.ebay.com/str/vintagepartssuppliers?_trksid=p2047675.l2563|Link to Ebay Store]] and Rusty Dusty Motorcycle Parts [[https://www.ebay.com/str/bialystreasures?_trksid=p2047675.l2563|Link to Ebay Store]] ))|  
 |{{:techtalk:ih:engmech:topmount_1_on_71_xlch_by_piniongear.jpg?direct&300|}}|{{:techtalk:ih:engmech:top_mount_hole_compilation_from_vintage_parts_suppliers_and_rusty_dust_motorcycle_parts.jpg?direct&300|}}| |{{:techtalk:ih:engmech:topmount_1_on_71_xlch_by_piniongear.jpg?direct&300|}}|{{:techtalk:ih:engmech:top_mount_hole_compilation_from_vintage_parts_suppliers_and_rusty_dust_motorcycle_parts.jpg?direct&300|}}|
 +
 +====== Center Mount Cross Brace ======
 +
 +  * The -57 parts catalog doesn't show or list the cross brace or the bolt to the frame. \\ However, it does show all three (frame bolt) cross brace washers to be under the straddle mount which is wrong of course. \\
  
  

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