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General Category => General Discussion => Topic started by: Phang on December 01, 2015, 08:53:34 AM

Title: Big twin rocker shaft retainer bolt - V7 Sport
Post by: Phang on December 01, 2015, 08:53:34 AM

I was reading the Guzziology earlier today and got stuck at this particular paragraph.

It contradicts with the parts manual of V7 Sport, the manual printed part# 9805 4314 as M6X12 bolt.

So what do I expect from a presumably unmolested 1973 V7 Sport? 12mm or 14mm?

If the bike has the 12mm bolts, do I replace them to 14mm bolts?

I am confused, please educate me.

Thanks.

Phang

(http://img.photobucket.com/albums/v198/Phang/guzziology_zpsjye4fjy9.jpg) (http://smg.photobucket.com/user/Phang/media/guzziology_zpsjye4fjy9.jpg.html)

(http://img.photobucket.com/albums/v198/Phang/rocker%20pin%20screw_zpsvrk6ufss.jpg) (http://smg.photobucket.com/user/Phang/media/rocker%20pin%20screw_zpsvrk6ufss.jpg.html)

Title: Re: Big twin rocker shaft retainer bolt - V7 Sport
Post by: mtiberio on December 01, 2015, 08:58:00 AM

do you own a vernier caliper? if so calculate what you need from first principles...
thickness of the washer (when flat)
+
thickness of the rocker tower that the bolt must pass thru
+
no more than the thickness of threads on one side of the hollow rocker pin.

any more than that (a mouthful) is wasted and could block an oil passage.

Title: Re: Big twin rocker shaft retainer bolt - V7 Sport
Post by: Phang on December 01, 2015, 09:21:13 AM

Quote from: mtiberio on December 01, 2015, 08:58:00 AM

do you own a vernier caliper? if so calculate what you need from first principles...
thickness of the washer (when flat)
+
thickness of the rocker tower that the bolt must pass thru
+
no more than the thickness of threads on one side of the hollow rocker pin.

any more than that (a mouthful) is wasted and could block an oil passage.

Thanks, your explanations make sense and easier for me to understand  :thumb:

Title: Re: Big twin rocker shaft retainer bolt - V7 Sport
Post by: Antietam Classic Cycle on December 01, 2015, 09:38:14 AM

Yes, replace the 12 mm "bolts" (hex head cap screws) with 14 mm long bolts. No matter what type of washer you use (schnoor, toothed, wave, split lock), the 14 mm length will engage the rocker pin threads fully, but still won't block the oil passage. Use grade 8.8 bolts.

Title: Re: Big twin rocker shaft retainer bolt - V7 Sport
Post by: Phang on December 01, 2015, 09:47:42 AM

Thanks Charlie, I think I got the picture now.

Only when the bolt is longer than 14mm then it stands a chance of blocking/reducing flow of the oil in passage drilled in the rocker pin?

Title: Re: Big twin rocker shaft retainer bolt - V7 Sport
Post by: Antietam Classic Cycle on December 01, 2015, 10:13:37 AM

Quote from: Phang on December 01, 2015, 09:47:42 AM

Thanks Charlie, I think I got the picture now.

Only when the bolt is longer than 14mm then it stands a chance of blocking/reducing flow of the oil in passage drilled in the rocker pin?

Yes, at 16 mm it will start restricting the flow of oil .

Title: Re: Big twin rocker shaft retainer bolt - V7 Sport
Post by: Phang on December 01, 2015, 10:21:35 AM

I read the same Guzziology paragraph again and it is all making sense now.

Can't learn just by reading a book, you also need the help from teachers and classmates.

Title: Re: Big twin rocker shaft retainer bolt - V7 Sport
Post by: rbond on December 01, 2015, 04:00:17 PM

And more than a mouthful is NOT wasted. It is just a lot more to enjoy! :grin: