Differences

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--- techtalk:ih:engmech09p [2021/05/30 01:49]
hippysmack created
+++ techtalk:ih:engmech09p [2021/06/28 23:17]
hippysmack [Center Mount Cross Brace]
@@ Line 1: / Line 1: @@
 [[:techtalk:menu|{{  :techtalk:gototechnicalmenu.jpg|}}]]
 ====== 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 also includes the 77-78 "head strap" between the heads (but does not tie back to the frame). \\
@@ Line 15: / Line 15: @@
 **Service Manuals**: \\
 Looking at illustrations in the FSMs: \\
-In the 1964 FSM, there a 2 illustrations in the book showing the left side of the bike and a very good detail of straddle mounted. \\
+  * In the 1964 FSM, there a 2 illustrations in the book showing the left side of the bike and a very good detail of straddle mounted. \\ On page 1B-7 picture (1B-2), in the front of the book, shows the washers on the bottom of the mount. \\ On page 3A-17 picture (3A-8), in the engine section, shows the washers on top of the mount under the bolt head. \\
-On page 1B-7 picture (1B-2), in the front of the book, shows the washers on the bottom of the mount. \\
-On page 3A-17 picture (3A-8), in the engine section, shows the washers on top of the mount under the bolt head. \\
-The 1967, 1969, 1976 and 1978 FSMs all show the washers between the head and the straddle. \\
+  * The 1967, 1969, 1976 and 1978 FSMs all show the washers between the head and the straddle. \\ These old books were printed using dot printers and scanning a picture to get a better view is not that easy as the dots in the ink get bigger as well. \\ But the washer doesn't show up on top in these books. \\
-These old books were printed using dot printers and scanning a picture to get a better view is not that easy as the dots in the ink get bigger as well. \\
-But the washer doesn't show up on top in these books. \\
 So even if one were to try and research from the manuals, it's still a crap shoot from there deciphering washer orientation depending on what manual you have. \\
@@ Line 35: / Line 31: @@
 \\
-CAN YOU ASSEMBLE THE WASHERS ON TOP OF THE STRADDLE MOUNT INSTEAD? \\
+**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. \\
-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. \\
-But all in all, it can be done. \\
+So you'll need more spacers there to make up that difference. \\
-However, due to the possibility of cracking the head at the tapped holes for the straddle mount if it doesn't line up correctly; \\
+The intake manifold fit determines head and cylinder position. ((ryder rick of the XLFORUM http://xlforum.net/forums/showthread.php?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. \\
+**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. \\
+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. \\
 And there shouldn't be any added stress to the motor when tightened down to the frame. \\
+Whichever way you choose to assembly the parts, there should be no space to "tighten down" to close up any space remaining after assembling the spacers. \\
+And there should be no binding between the straddle mount and the heads prior to or after tightening. \\
+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]] ))|
 |{{: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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