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KSever

Briggs Head bolts

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KSever
After taking my 170707 7HP Vertical Briggs apart to clean out the carbon I noticed I have one bolt longer than the rest. I haven't taken any bolts out of the original holes yet to clean the head cover, but I was wondering if anybody knows if this longer bolt has a perticular hole it HAS to be in? Because I know that someone has had this apart before and I would like to put it back together right if this is the in the wrong hole. The one it's in right now is on the bottom right side just below the valves. Thanks, Kris

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HubbardRA
Most of the time a longer bolt is for some type of bracket that may have been originally attached to the head. As far as I know the length doesn't matter so long as the bolt is not put into a blind hole where it will bottom, and there is sufficient thread engagement to allow torqueing. Bottom line - make sure all bolts are torqued properly. Rod H.

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PatRarick
There are supposed to be three longer bolts. They should be around the exhaust valve, the one you point out being the middle one. Was told at the Briggs school that the only purpose was to help with heat dissipation around the valve. Many of the later Briggs L-heads did not have longer bolts, but the bosses in the head in that area were lower than the rest so shorter bolt protruded farther out of the block thread. Never asked, but I assumed this was done to avoid the confusion of the longer bolts. Pat

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Kent
Though not directly related to your question... A tip I use when pulling a head off. I draw a rough outline of the head on an old piece of corrugated cardboard, like the flap off a cardboard box. Then, using a nail or something similar, I punch holes in it in the approximate location of each head bolt. When I remove a bolt, I stick it through the corresponding hole in the piece of cardboard.... When it comes time to put it back together, I can put each bolt back in exactly the hole it came out of.... Works for me! The foot-draggin' Clubhouse Custodian...

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KSever
Thanks for the tip Kent. I usually do that also but I figured this time when seeing just the one bolt longer I should see why and I knew this engine had been apart before. And if after seeing what kind of rigging was done to this tractor. I should check this out to be on the safe side with all the bolts in the right place. Terry, I cleaned it out about 2 years ago I think, but this engine did smoke just a little when you would start it or the governor would kick in and lost power. It did have a lot of carbon buildup. This time I took it a little further and put new chrome rings and a complete set of gaskets in also. So hopefully I won't have the buildup like I did this time. Kris

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Kent
Terry, The Owner's Manuals say to do it every 100 hours -- but that was in the days of leaded gasoline. With today's unleaded, I don't think you get nearly as much carbon buildup as you used to.... I've heard some people say that you don't even need to worry about it now -- assuming that the head has been off since we switched to unleaded and you don't have a 20-year old buildup in there... Kent The foot-draggin' Clubhouse Custodian...

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powerking_one
Terry, Kent: I agree about not having to worry about carbon buildup any more. My dad's 728 Broadmoor with a new 10 hp Briggs in 1975 NEVER had the head off in the 25 years we/he owned it. I estimate it had 1,500 or so hours on that engine when he sold the tractor. Tom(PK)

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BLT
quote:
Originally posted by PatRarick
There are supposed to be three longer bolts. They should be around the exhaust valve, the one you point out being the middle one. Was told at the Briggs school that the only purpose was to help with heat dissipation around the valve. Many of the later Briggs L-heads did not have longer bolts, but the bosses in the head in that area were lower than the rest so shorter bolt protruded farther out of the block thread. Never asked, but I assumed this was done to avoid the confusion of the longer bolts. Pat
If you look in parts book they'll show what Pat posted. If you have torn a few down, mother nature makes you look for the longer bolt.

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BLT
quote:
Originally posted by HubbardRA
Marc, All I ever use is a razor blade and a pocket knife. Try to not remove any metal with them.
I made a scraper out of an old narrow flat file and that has kept metal removal to a minimun. It's real sharp and I have the fingers to prove it.:(!

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charby5
Thanks Rod and Bob for the reply, I was just asking to see what different metheds you all used.I seen how Kris got his 7 so clean in his pic it just made me curious..thanks again guys. Marc..

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HubbardRA
Marc, I just purchased a 12 Hp B/S head from ebay. Looks like the combustion chamber was cleaned with an ice pick, it has so many deep dings in the flat surface that sits above the piston. Actually it looks like it was operated with a screw or something beating around between the piston and head. I can use it, but I'm not real happy about this.

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charby5
Hi Pat. Thats what I've used in the past too ..plus a shop vac afterwards to get the carbon dust and grit that gets in between the cylinder and the bore wall.Im not sure if thats necessary but I call it piece of mind I guess.. Hi Rod. If your not sure about using that head. Ive got a 30 cube head Im not using(13 hp)same as 12hp..Its not new but its in good shape.( hasnt been cleaned with ice pick)..if you want e mail me your addy info and I'll mail it to ya..thanks guys. Marc.. 5charb@hcil.net

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