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Motorcycle Repair/Oil leak from the oil orifice bolt



I have a 1988 Honda Shadow VT1100C motorcycle with 20K miles. I have a oil leak coming from the oil orifice bolt. This bolt located just above the oil pressure switch and is shown in the Haynes manual on pg 9-15, illustration 21.3, but there is no other information about this bolt in the manual or anywhere on the internet. I tried to tighten to the bolt, but it feels like there are no threads and I only made the leak worst. Any information on this bolt's purpose and how to repair it would be most appreciated!


ANSWER: Randy, I don't usually work on anything this new and don't have one available to check first-hand. My suggestion is to put a pan underneath the engine case and loosen the bolt up and remove it for inspection. Apparently it is used to reduce oil flow to some part of the engine case lubrication system. I couldn't find any real references to it either. Even the part number just comes up with the same drawings from Honda. I did look at some engine cases on eBay auctions and see the part and where it goes, but I don't know how it is sealed or the actual function of it. A bolt like that should have either an o-ring or gasket to seal the head from leaking. I don't see a separate part number for anything but the bolt, so either the o-ring comes with it or there is some other way for it to seal up against oil pressure. Check the bolt for damaged threads and the hole for any signs of damage or perhaps old sealant that was used at the factory to install the bolt.

Take it apart and take some photos for me, if necessary.

Bill Silver

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Well I removed the oil orifice bolt and it looks fine, but I believe the threads in the aluminum case are stripped. I suspect the previous owner or a service person may have attempted to tighten the bolt and stripped the threads. The reason I say this is when I removed the bolt there was a small piece of steel wool wrapped around part of the threads of the bolt and I'm unable to tighten the bolt. I really don't want to drill and tap this hole out. Any ideas on a temporary or semi-permenant fix?


Randy, depending upon the depth of the threads and the thread pitch size, you might be able to work a Heli-coil or Time-Sert type of thread repair into the damaged threads. If that isn't possible and the thread depth is too shallow to be able to drill, tap and install a thread repair, then the other options are either RED Locktite or JB weld epoxy to just glue the bolt into place permanently. Because it is a special orifice bolt, you can't just drill out the old threads and tap for the next-sized up bolt and be done with it.

You may want to consult with a machinist in your area for other options, including making a new threaded mount from aluminum stock and having it heli-arc welded to the case.

Bill Silver  

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Bill Silver


Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.


I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

VJMC (Vintage Japanese Motorcycle Club) of North America

VJMC newsletter, as editor for two years and as contributing editor currently.

3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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