Torquing the studs

[isaac]

Heyo! I'm in the process of reassembling my new GS850GL's engine, and was hoping I could get some help. I've cleaned the base gasket surfaces (a 2 hour ordeal) and removed the old studs, and am ready to put new ones in and then slip the cylinders over the pistons.

The questions: How do I torque down the studs, and how much torque? Should I put the cylinders on before the studs, or after? Thanks for the help. Hopefully I'll be on the road soon!

[Anonymous]

Snug down the studs lightly. Install the cylinder with the base gasket cemented onto the bottom of the cylinder so you don't rip it. Then put on the head and torque the cylinder nuts. This will tighten the studs properly. You usually have to torque in a specific pattern and do it twice... once to one value and then the second time to a slightly greater value. Consult your manual for this procedure as it veries from bike model to model.

[SqDancerLynn1]

Tighten the studs to 5-10 ft lbs. Assamble the motor & torque the nuts to 15 lt lbs then tighten to 27 ftl lbs Let it set for a few hours and retorque to 27 ft lbs again tighter the small outer bolts to 12-15 ft lbs run the bike for 500 mi pull the cam cover retorque again to 27 ft lbs & recheck the valves. Then forget about it & ride

[Anonymous]

Geesh Lynn... the similarities between KZs and GSs is scary! The KZ requires 18 lbs on first torque and 25 on second torque and the two small 6mm bolts are about 9 or 10 lbs... I told the guy to snug the studs as most 3/8 or 1/2 toque wrenches are not very accurate below 10 lbs/inch. I use a 1/4" torque wrench calibrated in in/lbs for less than 10 lbs/inch and then a 1/2" for the cylinder head nuts. That is why I said "snug" as it is a ~5-10 lb/inch thing...

[isaac]

Thanks for the tips so far. I've got a question about the bottom of the head and top of the cylinder mating surface. It seems as if they've got this wierd cross hatch pattern in them that's formed into the metal. Is that supposed to be there, or should I sand that down until it's smooth? Thanks.

[Anonymous]

A milling machine made those swirl marks on the mating surfaces back 20 years ago. Leave 'em be. Clean the old gasket off... sometimes I resort to using Permatex Spray gasket remover. It softens the stuff up and turns it into nasty disgusting goop that is easier to scrape. I use a butter knife with the tip broken off and then put an edge on it with a grinder for these mating surfaces. A wire wheel brush (fine or brass) on a drill is also handy as some of the mating surface are accessible to the brush. And if you use the Permatex spray, don't do a HUGE area with it as it dries and the gasket/goo hardens again. When you are done, I recommend cleaning the mating surfaces with acetone. Don't get that stuff on your skin or breathe it. It killllllllls brain cells. (I know).

[SqDancerLynn1]

The gasket needs something to grab onto. Leave it as machined

[isaac]

Thanks for the tips, but I'm still not sure I understand what is and is not gasket and what is mating surface. It's brown right now, but I can't see how a gasket would leave anything behind because the replacement head gasket is made out of all metal in a multi-layer plate. I don't see how that could have stuck to the head or top of the cylinders.

To clarify, there are no swirl marks like on a normal cylinder head. This is a well defined, bumpy, metallic raised surface that looks like the face of a meat tenderizing mallet. There appears to be no edge to it, so I don't think it's actually gasket material. I've done a good dozen head gasket jobs on cars, and this looks nothing like I've ever seen.

So what is that supposed to be? Thanks for the help.