70-71 merc 650 fuel bolt snapped

[Unarmed]

I was removing the fuel pump on my 650 and 2 of the bolts snapped, one I was able to get out with vicegrips, the other is snapped off to low to grip. so I was wondering how to continue from here. I would like to get it out but I honestly dont know how. any help would be greatly appreciated.

 

[diaric]

Re: 70-71 merc 650 fuel bolt snapped

ever use an easy out? you can get them at an auto/hardware store. the hard part is drilling a hole in the bolt to get the easy out into. then thread it out. about half the time, the bolt loosens up while drilling and comes out easy with fingers

 

[Unarmed]

Re: 70-71 merc 650 fuel bolt snapped

nah, I havent used one, but when I told my father the problem he gave me the same response... guess I am gonna have to try an easy out...

 

[Silvertip]

Re: 70-71 merc 650 fuel bolt snapped

If this is a stainless steel bolt, good luck drilling. However, you have few choices. My suggestion is to visit your local hardware store and see if they have reverse twist drills. These are drill bits that you run counter clockwise rather than clockwise. If you use one of those, the drilling operation will likely result in the drill bit simply backing out the bolt. Places like Lowes, Home Depot may not even know what you are talking about so check your yellow pages for drilling equipment supply houses.

 

[j_martin]

Re: 70-71 merc 650 fuel bolt snapped

Stainless isn't hard to drill if you know how. The characteristic that gets in the way is that it will work harden.

The bit must be sharp, good quality brand new is recommended.
use WD40, or kerosene for lubrication and cooling.

Plunge drill, that is drill hard for about a second, then back out for a second or 2. Don't ever run a drill against the work with light pressure, it'll harden and be impossible to drill in a heart beat.

If you just take an old drill and try to drill a hole in it like it's soft steel or aluminum, you will be totally amazed at the damage to the drill, and the coresponding hardness of the stainless. If you do it right, it's just a little harder than drilling mild steel.

hope it helps
John

 

[Unarmed]

Re: 70-71 merc 650 fuel bolt snapped

I dont think these are stainless... they appear to be the original parts (like most the parts in the engine...) they were super easy to snap. I snapped it with light pressure from my hand (using a socket wrench). on the bright side I only have to get out one bolt by drilling...

not sure if this helps but the head of the bolts are all stamped "SEMS"

 

[Unarmed]

Re: 70-71 merc 650 fuel bolt snapped

the bolt on the left just the head snapped. the one thats still in the motor is the one on the right, it is about the same length as the one in the center.

 

[diaric]

Re: 70-71 merc 650 fuel bolt snapped

sure got a warp to them bolts, lol.
look like regular steel. if u have to drill, follow the instuctions for stainless and use good bits. use bit and easyout size that shouldn't come clost to threads. best to run a tap through after and clean threads. problem is steel bolts in alluminium causes a reaction and they rot out unless pipe dope used on installation

 

[Unarmed]

Re: 70-71 merc 650 fuel bolt snapped

ah, so it is steel. they seamed too weak to be steal but I didn't know about that reaction...

 

[Unarmed]

Re: 70-71 merc 650 fuel bolt snapped

wow... I still havent gotten around to doing this...
does anyone know what size bolts these are...
I misplaced them and it would make my life much easier if someone knows the size of them...

 

[Chris1956]

Re: 70-71 merc 650 fuel bolt snapped

Unarmed, Is that fuel pump mounted on the transfer cover of the motor? If so, the bolts are about 3/16" with course thread. If the fuel pump mounts on the lower cowling, the bolts are thinner, maybe 1/8" with fine thread. These both fall into the "numbered" bolt size, say size 10/24 for the transfer cover mount and 8/36? (fine thread) for the cowling mount.