81 GS750E Valve adjustment questions

[woodsietx]

Hey everyone,

I've plan to do the valves on my bike tomorrow. I've been researching the process here and still have some nagging questions. I'd like some advice. I've never gone this far into a bike before and don't want to make any newbie mistakes.

I have a printed copy of the 16V valve adjustment notes from BassCliff's site. Those look invaluable. I've bought new tools, I have gaskets, tappet gauges, etc... I have the service manual on my laptop, ready to use.

I want to ask what chemicals am I going to need to pull this off? I've seen the note to put some WD40 or oil on the cover gasket. That one's easy. My bigger concern is with anti-seize and thread sealers. I have a set of allen head bolts to use as replacements. It is best to put some anti-seize on these? What are the specifics of this material, ie type and brands? I have a small tube of thread sealer I used on the petcock screws but that's not what I want to use here right? Do the allen heads require washers?

I've also found the recommend to put gasket sealer on the half-moons (I have new) but am unsure what to use here too. I'd ask for a recommend on type and brand.

Lastly, are there any BIG pitfalls to look out for since this is my first time removing any of the engine covers? I know the top of my engine is clean. The carbs are off. Since I do not have the carbs back yet, would I be better off waiting to do the work since I can't start it?

I feel weak willed asking all this but I don't want to damage anything. It'll two months next weekend since I bought the bike and still can't ride it. Too bad so sad right? The price for fixing things right.

Thanks.

Woodsie

 

[Nessism]

When you purchase a 28 year old vehicle you can not expect to just jump in/on and go. Doing all the maintenance is a good thing and you should not lament it.

If those allen head screws are stainless steel you need to use anti seize on them. Brand and type are not overly important, just go to your local auto parts store and buy some - copper type is better than aluminum type if you have a choice.

Gasket sealer on the curved portion of the half moons doesn't hurt. I use either Threebond or some of that Ultra silicone stuff - can't remember the brand. You only want a very thin layer and frankly since you have new half moons, you can skip the sealer if you want.

Keep going...

 

[headsbikesmopars]

You also should use a torque wrench for the valve cover bolts. The torque on these are only 7.0 Ft.lbs. that is only 84 inch lbs. NOT very much. many GS'ers have pulled these threads. Sears sells a good inch pound wrench for cheap. A very good investment for your maintainenance program if you are going to service your own GS.

Terry

 

[Guest]

Good for you for thinking ahead & asking questions... best way to prepare for a "new" task.

As compared to other tasks on these bikes, a valve adjustment is rather simple & provides a very noticable difference in engine starting/running.

A few tips I would offer are:

- Start today by spraying the valve & breather cover bolts with PB Blaster. Sometimes these have been over-torqued by the PO, and they're easy to snap. Take care when removing them.

- You may have to "tap" the valve cover around the edges to break it free from the old gasket - especially true if this is the first time the cover has been off. Harbor Freight sells an inexpensive soft rubber mallet for around $3. Good to have one...

- You will most likely spend the bulk of your time scraping the old gasket material off the mating surfaces. A REAL PITA. Take care not to gouge any of the surfaces while cursing the PO for not doing this earlier. I use a small, very sharp wood chisel for this task, but it's easy to gouge the aluminum with that tool - takes a LOT of patience & a steady hand.

- Stuff rags around the inside of the head to keep all the little pieces of gasket from falling into the engine while you scrape.

- The old gasket material MUST be removed rather completely or the new gasket won't seal & it will seep oil...

- Someone here (RapidRay I think) told me his way of making a tappet adjustment tool - go to a buliding supply store a pick up a couple of drywall/decking fasteners that use a "square-head" driver. Match the size of the fasteners' square depression to the size of the tappet stem. Screw that fastener into a short wooden dowel and there you go - valve adjust tool for the 16v engines.
​

Good luck,

Mike

 

[woodsietx]

Hey everyone.

Thought I'd give a quick status reply on how things went Sunday. The word debacle might be too strong a word but I did manage to get a few things done.

I first want to thank the three previous posters on this thread. I used information from each of them to help make the job easier.

Brand and type are not overly important, just go to your local auto parts store and buy some - copper type is better than aluminum type if you have a choice.

On the way home Sat. I purchased some copper anti-seize. Imagine my chagrin when I found an unopened tube of the same stuff in my checmicals box. Luckily, I kept the receipt.

You also should use a torque wrench for the valve cover bolts. .... A very good investment for your maintainenance program if you are going to service your own GS.

I already had one. Too bad it doesn't measure small enough. I don't have the receipt for this one. Hopefully I can exchange it or get store credit. I'll check at Sears this week for that "cheap" one. Not that I needed it anyway. See below.

- You may have to "tap" the valve cover around the edges to break it free from the old gasket - especially true if this is the first time the cover has been off. Harbor Freight sells an inexpensive soft rubber mallet for around $3. Good to have one...

- You will most likely spend the bulk of your time scraping the old gasket material off the mating surfaces. A REAL PITA. Take care not to gouge any of the surfaces while cursing the PO for not doing this earlier. I use a small, very sharp wood chisel for this task, but it's easy to gouge the aluminum with that tool - takes a LOT of patience & a steady hand.

The hammer cost me $1. It worked fine.
Fortunately, almost the entire gasket came off in one piece. I spent more time cleaning the cover than the head. I found a gasket scraping tool by Craftsman I bought that worked fine.

The good news. I was able to adjust all the valves with a minimum of trouble. Most were a bit loose. I followed another members advice to set them so the .004 would go under but the .005 would not. I even remembered to re-check after I tightened the lock nut.

How tight should the lock nuts be? I couldn't use a torque wrench on them. I tightened until they were snug and just a touch more. I almost thought I had screwed up one of the first ones I did (#3 intake) and was about to loosen it when it came back to me that I had already cranked the engine around and the tappet clearance was no longer "right" with the valves in that position.

Bad news. I bought a set of stainless socket bolts for a GS750 and I couldn't find anything that matched the 16 cover bolts. There were 4 replacements that worked for replacing the Phillips head bolts and the three ignition cover bolts. So I snugged up the four bolts I had by hand to make sure the cover was tight enough to prevent crap from getting past it. I'll get with the bolt supplier to find out if I got something wrong from them.

More bad news. You know how the 16V valve adjustment guide mentions that the tach gear can be difficult to remove? I found it much easier when your bike has the sleeve type that split in two pieces. "Oh wait," you say, "that's a one-piece part." Oops, guess what happened to mine?

I'll cover those two bad news topics in separate threads so they aren't buried in this thread should others have the same question.

I also got my carbs back Sat. I was so frustrated by the way things went Sunday, I still haven't opened the box. I will this week sometime.

I suppose I best rethink my plan to quit grad school and become a certified GS mechanic.

I'd show some picts but they aren't on this PC. I'll add them later.

BTW, I was able to replace the o-ring on the oil filler cap without too much struggle. We'll know for sure once it's running.

Woodsie