GuzziYang Posted September 28, 2011 Share Posted September 28, 2011 I don't know how a engine mount bolt can fall off or come lose but mine did. It only got 5,500 miles on my Le Mans and I have no idea how this could happen, could the factory forgot to installed it in the first place? My right side front engine mount bolt is missing (the one next to the exhaust headers). Can anybody tell me the size, thread and length of the allen bolt? I'd check the parts book and it only gives a part number but no size or any spec. Thanks Frank Link to comment Share on other sites More sharing options...
gstallons Posted September 28, 2011 Share Posted September 28, 2011 I looked at the one on my bike. It is a 12x35mm socket head capscrew. You can get one at Fastenal. Also there is a washer beneath the bolt. The lock washers I use in these applications are called high collar lock washers. They are the same diameter as the head and will fit the bore of the hole in the frame. Link to comment Share on other sites More sharing options...
Tom M Posted September 28, 2011 Share Posted September 28, 2011 Engine mounting bolts on any bike can loosen up over time. I found a few engine mounting bolts had worked themselves loose when I bought my bike with 7000 miles on it. Check them all including the porkchop bolts and hit any loose ones with blue loctite. Link to comment Share on other sites More sharing options...
mznyc Posted September 28, 2011 Share Posted September 28, 2011 I better check my engine mount bolts! Link to comment Share on other sites More sharing options...
stormsedge Posted September 29, 2011 Share Posted September 29, 2011 My bike was missing the right one when I purchased it second hand. The guy I bought it from was plainly scared of riding it...the handling really tighened up with replacement of the bolt. Loctite is your friend. k Link to comment Share on other sites More sharing options...
GuzziYang Posted September 29, 2011 Author Share Posted September 29, 2011 Thanks for the feedback and info. 12mm bolt x 35mm long. How about the pitch? 1.25 or 1.5? My local hardware only carry corse thread 1.7 so I guess I have to mail order or special order. Link to comment Share on other sites More sharing options...
Mike Stewart Posted September 29, 2011 Share Posted September 29, 2011 I believe it is a 1.75 thread pitch, infact if you need a factory bolt with washer, I think I have one from when I parted my V11 Sport out years ago. Just send me your address and I will get it in the mail. Mike Thanks for the feedback and info. 12mm bolt x 35mm long. How about the pitch? 1.25 or 1.5? My local hardware only carry corse thread 1.7 so I guess I have to mail order or special order. Link to comment Share on other sites More sharing options...
GuzziYang Posted September 30, 2011 Author Share Posted September 30, 2011 I believe it is a 1.75 thread pitch, infact if you need a factory bolt with washer, I think I have one from when I parted my V11 Sport out years ago. Just send me your address and I will get it in the mail. Mike Thanks for the feedback and info. 12mm bolt x 35mm long. How about the pitch? 1.25 or 1.5? My local hardware only carry corse thread 1.7 so I guess I have to mail order or special order. Thank you for the offer Mike! I could definitely use the bolt and washer, Pm on the way. This time blue lock tight all the frame bolts and pork chops. Check with MG cycles and they don't carry the engine mount bolts so its either dealer or specialty stores. Link to comment Share on other sites More sharing options...
gstallons Posted October 2, 2011 Share Posted October 2, 2011 If you don't come up with one, I have one. The ones on my bike are plated but the one in my spare bolt bin is black......... Just let me know!!!!!!!!! Link to comment Share on other sites More sharing options...
GuzziYang Posted October 4, 2011 Author Share Posted October 4, 2011 The bolt arrived today, thanks Mike! It is 12mm bolt 35mm long by 1.75 thread pitch. No wonder the bolt fall off as 1.75 thread pitch is too corse/wide for engine mount with vibrations to dealt with. All the Japanese engine mount bolts are 1.25 pitch which is fine thread. I guess the Italians never learn or just as stubburn as the British I'll thread lock all the engine bolts for sure after this. Frank Link to comment Share on other sites More sharing options...
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