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Discussion Starter #1
Is this correct:

Smaller cylinder studs:
7.2 ft/lbs

Larger cylinder studs:
36 ft/lbs

Head studs:???

I have always been told to make sure head studs are CLEAN (dry) before installing as oil in the threads can cause a false torque reading (hydrolock them). But I was just searching for torque specs and some people said to make SURE there is oil on them???

Should I use anti-seize? Anything else to consider when reinstalling the head/cylinder?

I have ALL new hardware/gaskets so I hope I Only have to do this once lol.

Thanks guys
 

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Those cylinder stud torques are right.

.............................Q'ty/ Ft Lbs
Cylinder head Bolt M9- 4 - 25
Cylinder head Bolt M9- 2 - 27
Cylinder head Bolt M6- 2 - 7.2

That should help some
 

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Please go to the link below and download the service manual
Modded Raptor - For the rider that can't leave anything STOCK!

As a "common practice, you ALWAYS lubricate bolts when torque is applied. Due to friction of the bolt turning (mainly the head) it will cause the "REAL" torque of the bolt to be less than you torque wrench reading. Hydrolocking can only occur if you are crazy about lubing everything. I use "good" oil - synthetic, dip the bolt, let run off, then install, making sure bolt head is drenched, threads are wet - not soaked.

Better lube = less losses on the shoulder of the bolt/nut - ARP bolts use special moly lube to decrease this frinction as low as possible to give "The most accurate fastener torque"

Without any lube - your "REAL" bolt torque could be 50-70% of your torque wrench reading.

Unsure of yamaha torque instructions, Please read the service maual, and follow it.

My $.02 (if obama hasn't taxed it yet)
 

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From Service Manual Page 4-14 (page 163 pdf)

NOTE:
• Lubricate the cylinder head bolt 1 and 2
threads and mating surface with molybdenum
disulfide grease.
• Lubricate the cylinder head bolts 3 threads
and mating surface with engine oil.
• Install the washers with their blunt surface
facing the bolt seat.
3. Tighten:
• cylinder head bolts 1: = 135 mm (5.31 in)
• cylinder head bolts 2: = 145 mm (5.71 in)
• cylinder head bolts 3
• cylinder head bolts 4
NOTE:
_
Tighten the cylinder head bolts in the proper
tightening sequence as shown and torque
them in two stages.
 

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FYI

The service manual says there are different lenth bolts (5.31" - 5.71) make sure you know where they go. even though the use similar holes.

Also two stages of torque sequence.
 

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Discussion Starter #6
Is the Grease mandatory? I have some good klotz synethic oil I can make sure I get the threads lubed up.

I am downloading the service manual now, thanks.
 

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grease can support more pressure than oil, meaning grease will preform better than oil. It is not so much the threads, but the sholder/head of the bolt/nut. The flat spot under the hex head. When you tighten, it lays flat on the washer or the head, causing friction.

I lube everything, dipped in oil. You'll probably be ok with good oil.

Never screw without lube:thumb:
 

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Discussion Starter #8
I bought some Klotz Assembly lube with moly and some other stuff.

I didnt get very far though... The Diamond piston I bought came with these "spiral" wrist pin clips...which of course take a special tool to install.
 

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Discussion Starter #9 (Edited)
I got everything put together but the cylinder head is just sitting on the cylinder (not torque down yet).

.............................Q'ty/ Ft Lbs
Cylinder head Bolt M9- 4 - 25
Cylinder head Bolt M9- 2 - 27
Cylinder head Bolt M6- 2 - 7.2

Which m9 bolts are which? I know two are longer, two are shorter. The above chart shows the 25 ft/lb bolts as having "4" quantity. How is this? The only 4 that are the same are the cylinder bolts which were 36 ft/lbs.

I think if im thinking correctly, the 4 longer bolts that go from the top of the head down to the cylinder are all 25 ft/lbs. The two small stubby bolts that go from the bottom of the cylinder up into the head, these are the 27 ft/lb ones?

Lastly...how do you check the torque on the allen head screws? I think I have the appropriate allen head socket, but I dont see it fitting in the space provided (between the head of the bolt and the engine). How do you guys get around this???

Thanks so much!
 

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Discussion Starter #11
Thanks daniel I will have to look for some long allen drives.

Do the torque specs I listed sound right?
The 4 long bolts (2 long, 2 a bit longer) going from the top of the head down into the cylinder - 25 ft/lbs
The 2 short stubby bolts going up into the head from the cylinder - 27 ft/lbs?
 

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yes... the side allens torque are not a requirement for compression retention but a guidelinethere are oild to keep the gasket from leaking oil
 

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Discussion Starter #13
Ok worst case scenario I will figure out what 7.2 lbs feels like on another bolt and just get it pretty close on the allens. I think I can probably get within a ft/lb or closer which should be good enough.
 
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