HELP!! Missing Bolts on rebuild.

[Korbs67]

Just when I thought I'd be firing up my rebuild this weekend I have two extra bolts (pictured: M8x 1.0 2-3/4") and two empty holes (pictured) missing bolts. Problem is that the "left over" M8 bolts do not fit! Too small. I have maticulously and methodically put this power head back together and I just can't believe I'm left with two extra bolts and two openings that I dont have the bolts for! I'm just laughing at myself.

My problem is locating where the two M8 x1.0 bolts go and replacing the two bolts that I apparently misplaced. I looked at my schematics for and can't figure out the bolt I need. I tried a 3/8-24x 3 from Lowes and it doesnt thread so I know its not a 24. I thinks it's an 18 like the other cylinder head bolts that are ofcourse much shorter

When I originally bagged the M8's I labled them a cylinder block, I reviewed my video and photos and never referenced these darn bolts!

Can anyone tell me what bolt size these holes take? I'm inclined to say just a 2.75" version of the normal crankcase bolts of a bolt size .312 x18. What is a .312 equal to?

Sorry for confusing explanation I'm happy to clarify more if needed. I appreciate any help on this!

KK

 

[Georgesalmon]

Re: HELP!! Missing Bolts on rebuild.

Can't help you on where the bolts go. But, .312 is 5/16". Can be either 18 or 24 threads per inch. .312 is also very close to M8. You sure those are not metric? The ones in the picture look like 18tpi. Measuring bolts is from the bottom of the head. Those look like 2 1/2" long.

 

[JDusza]

Re: HELP!! Missing Bolts on rebuild.

Let's back up. It might help to tell us what you were working on, what was your original goal. That will point us in a direction.
Serial number will get us to a schematic to help look up parts.
Word of caution....don't mix English and Metric units.
J

 

[Chris1956]

Re: HELP!! Missing Bolts on rebuild.

Looks like you split the crankcase. Sometimes the length of the crankcase bolts varies a bit. You could have put shorter bolts into deeper holes or vice versa. A lot of times when a bolt is placed in a hole just to the threads, the length that sticks out is the same as all the others, unless you have it in the wrong hole. if the bolt doesn't stick out the same amount, it is too short for the hole.

 

[Korbs67]

Re: HELP!! Missing Bolts on rebuild.

Serial Number is 0B3967.. 1989 60hp. Mercury.

I blew piston one it overheated due to no water being pumped and I believe the fuel pump going bad. Piston was bone dry, so was the top carburator and fuel pump and impleller was shredded..probably the original.

Yes literally took apart the entire powerhead and motor. Split the cylinder block. Changed P1. New rings on P2 and P3, new needle bearing al round and a top main bearing. I buttoned it up back up it went together nicely. Replaced water pump, new fuel pump the diaphram was hardened, new rectifier (I remembered that my main battery always petered out so I'm starting with the rectifier and understand it could reach up into the stator among other parts as well).

The only part to put back on are the carbs, cover,

throttle assemble and ****ft assembly and obviously the cowel.

I want to clarify that the two bolts pictured DO NOT fit the opening. They need a larger diameter and I think they might be slightly too short. I measured the dia of the bolts in the pic, my calipers say .306-.307".

The .312 x 18 (item 14 in the schematic) is the only length cylinder head screw that looked to be the ones I'm missing.

Thanks!

Korbs

 

[Korbs67]

Re: HELP!! Missing Bolts on rebuild.

RESOLVED ISSUE.

The picture tells the story. The hidden area I was looking for is near the lower end cap. I hope this thread saves someone some time.

Thanks to all who tried helping me.