Hi.
For Christ sake, someone here please help me out on this. I joined this group specifically for this one subject, but happy to be part of more here. I'll dive right into it .I hope my answer is here. I've run out of patience searching for an answer. Maybe God is here. I have the Manual, but no mention of my question. "What is the tightening sequence of the SEVEN bolts of the cylinder and cylinder HEAD? The piston cylinder has ONE bolt (M6). Cylinder Head has six (two under camshaft M10,two outside right M10,and two outside left M6). Total =7.
Do I torque the ONE bolt from the piston cylinder first? Or hand tight first? I simply do'nt know where to start the sequence. The camshaft cap bolts are easy. they are numbered. Everything else is clear to me. Too bad my first post had to be this way. Oh, almost forgot. 2013 KX450F
Thanks for reading.
And sorry for the poster size pics

 

If like most engines, it will do a cross pattern on main cylinder fasteners whichever they are, those are the critical ones and the ones listed specifically for my KLX250. The norm for most. The three outer bolts could be done along the way, but crossing on the main four is the method. Do 33% torque value on all four, then next pass did 100% torque value. Look further on in your manual, in the KLX manual they had the section further on in it than I expected. The KLX fasteners were all internal. Yours has two inside two outside, but still the same process.

This may help:

 

Looked at entire manual again. Nope. Not there. Just mentioning that if pattern not shown, criss cross. For such a critical reference, i'm surprised of the manual's "just wing it" instructions. I totally understand the criss cross for the top four bolts. But what comes first, them, (M10) or the M6 bolts on the outside? Note; piston cylinder has a single bolt M6 (exact bolt as the two outer head bolts).
Can anyone else chime in here? Your diagram helps confirm my theory, but need more info concerning other (outside bolts) My GUESS is that they should be torqued first, or at least partially.

 

No, the four around the piston bore should be torqued first, then the ones outside the head should be done. Those on the outside are just closing against the possibility of a non-pressurized oil mist leak, the four inside around the piston are sealing the cylinder head to the cylinder against compression and firing pressure. That is why they are torqued first. Same happens with the 250. Tighten the fasteners around the cylinder bore first, then the outside fasteners, both the ones on the head and the one on the cylinder. Again all those do is keep mostly non-pressurized oil mist in the engine, where those four fasteners around the cylinder bore are highly critical to have even tightening.

 

Appreciate the follow up. I'm getting much closer to some final answers. we are of course comparing two diff bikes, but can relate. some of your/our terminology is not crystal clear to me. trying to be clear, but not insulting to make you think I don't think you know sh.t . lol .
So.....when you mentioned above, "the four around the piston bore" should be torqued first. Well, do you mean the HEAD? Because MY terminology of piston bore, is where the piston is and there is ONE. (M6) See Pic. Two more M6 just above on the HEAD. Again, sorry if i make things too complicated. That's why I attach pics.
So with that said, using the pics here, any way you (or anyone) can number the sequence. More info = less questions. 👍🤐 This may seem a simple task to others, but so far, this is the only place I'm getting anywhere. I know this is critical. And i get very **** of my work. Did not come this far just to make guess work and warp my Sh*t! Thank you very much for your time .

all three bolts here are same size and torque M6


see all seven bolts

 

I think what you are saying is......torque the 4 head bolts first (two under cams, and other two outside, right of head) Then ....???

 

That's what makes sense from the functional point of view. Tighten the head bolts that surround the cylinder first, the ones in the second and third image. They are what seals the cylinder bore, holding against the pressure from the burning fuel in the cylinder. .

Then any outer bolts like the ones on the outside of the cam drive in the first image. They just pull down on the outside to seal against any oil leakage and are not as critical as the four main head bolts for even tightening around the bore.

Pretty much exactly like the KLX, inner bolts around the cylinder first, then the outer ones second. In fact the outer ones (actually located inside the cam drive tower) on the KLX are 6mm versus the 8mm main head bolts around the cylinder bore.

 

KLX678
Thank you very much for taking the time to explain. You took the guess work out even though we're talking about diff bikes. Suks that the manual does not get into details on the sequence.
I don't own a million dollar torque wrench, hopefully my $20 one will do.
Pic is for fun

 

@johnny rtepsol I have a couple of the clicker wrenches sold by Harbor Freight. I read CarCraft's testing and they proved to be accurate. I still do use a beam style torque wrench on some smaller fasteners, because I have had a 3/8 drive beam style I bought years ago. I had a Snap-On tool guy test it on his bench tester and it was dead on. So I still use it. Things like the fork clamps and smaller fasteners I do it just to avoid snapping one. I have a 1/2 drive beam style I occasionally use, but these days on axles and such I will use the Harbor Freight one.

Have fun with the bikes. My street bike is the XSR700 and it has been great.