7 broken bolts all at once!
**Let me start off by saying Hello Everyone!! I've been building my first motorcycle (2007 1200C) for the last 3 years in my garage with borrowed tools and little know how. I've used this forum and a few others to learn as much as I can during process. So Thank You All for the knowledge so far!

Now my dilemma...

While trying to replace my front rocker gasket (which was burnt) I turned the engine using the sprocket (motor is out of the frame) and got both rocker arms in the down position. The pushrods both spin freely.

I bought a brand new inch-lb torque wrench and began to reassemble the rocker following the manual directions. I tightened the four inner big bolts in a cross pattern to spec 1/4-1/2 turn each. I then began tightening the 3 midsized bolts in a clockwise pattern 1/4-1/2 turn each to spec. The first two made it to spec, and as the third bolt hit spec and the torque wrench "broke," ALL SEVEN BOLTS were snapped at the head!!

I was able to remove them with my fingers so they weren't cross threaded, they weren't over tightened or bottomed out???

****I've been looking at this now and the pushrods and the valvesprings are holding the entire lower rocker cover about a 1/16" above the head when placed on there. I did not move the engine while it was apart and I cant figure out how 7 bolts snapped all at once... And now I have to find new bolts somewhere.

ANY ideas how or why this happened??? Any help locating proper bolt part numbers and/or sizes???

Thanks in Advance!!!

 

Upon thinking about this. I'm willing to bet each bolt was breaking as I put them in and just didn't realize until the 7th bolt cause I such a noob. I'll be crying in my closet now while paying dealer prices for bolts I broke.

 

I cannot help with why I can only show you what is in the manual but it looks like you have that covered.

ROCKER COVERS
NOTE
Before installing a rocker cover assembly on a cylinder head,
turn engine over so that both lifters for that cylinder are on the
base circle (the lowest position) of the cams.

BASE CIRCLE The "base circle", also known as the "heel", is the lowest point of the camshaft lobe and is the place where the valve is in the closed position.

1. See Figure 3-38. Install new gasket (16), with the bead
facing up. Place inner rocker cover assembly (8) (with
rocker arms and shafts) into position, fitting ends of push
rods in rocker arm sockets.
NOTE
To avoid damage to push rods or rocker arms, do not turn
engine over until both push rods can be turned with fingers.
2. Install fasteners (13, 15, 14). Slowly snug all fasteners in
small increments (one turn at a time). Use a cross pattern
on the four large bolts (13) that fasten the inner rocker
cover to the head. This will bleed the lifters. Tighten
fasteners in the following sequence:
a. Tighten bolts (13) to 18-22 ft-lbs (24.4-29.8 Nm).
b. Tighten bolts (15) to 135-155 in-lbs (15.3-17.5 Nm).
c. Tighten screws (14) to 135-155 in-lbs (15.3-17.5 Nm).

I have switched to using Nm to alleviate having to remember inches and feet.

 

First off I would make sure your not using ft lbs instead of in lbs. Then make sure your torque wrench is not giving you false readings. A good quaility torque wrench is what you want, the cheap ones are known to be way off.
As far as the bolts go, if you know the thread size and length, you should be able to go to a hardware store and get some good quaility replacements.

 

Welcome to the forum!

Yeah, that's frustrating. I agree with whylee, probably a torque wrench that's not well calibrated (even new they can be off, especially in the low inch lbs range).

Take your bolts to a hardware store and match up. Make sure to get grade 8 replacements.

 

If you were just installing the lower rocker box, and did not even get to installing the rockers, I can't see what would keep the lower box from mating. If the lifters needed to bleed down, that would affect your top cover installation. I suspect it could be improper use of torque wrench, or it's not calibrated correctly, or you misread inch pounds and foot pounds. Tt happens more often that you would think, especially because the manual shifts between inch pounds and foot pounds without reason at times. Anything I see in inch pounds tells me "hand tight" at most.

John

 

Good one ... You almost "had me" there