1980 GS 850G Engine Rebuild

[Burk Ferden]

Well riding season is never over when you've got heated gear, but I guess its okay to take a break from the old suzuki and tear it apart to work on it. I started this thread in the wrong section so I thought I would re open it to make way for some interesting stories and talk about the engine of this wonderful bike.

Recently a friend I decided to put a little work into my Sweet 1980 GS850G. The majority of the work is going to be on the engine. I am the 3rd owner of this bike and when I purchased it the speed drive was dead and needed to be replaced. Therefore, the 26,000 miles on the odo its a minimum amount that is on it considering once I got the carbs cleaned I drove it for at least another reregistering 10K. At the end of that summer the engine started leaking oil pretty bad. Guaranteed the engine gaskets needed to be replaced.

We decided to rebuild it as much as possible. After removing the cam cover and inspecting the leaking there was a noticeable amount coming from the next level down so we loosened up the head and removed it. There is a terrible amount of carbon on the piston heads but they look pretty snug around the bore.

Let me say that this is my first time in the engine this deep. I have the clymer manual and it has been a great help so far. I am not too afraid of putting this thing back together because it doesn't seen that hard. As long as I follow the instructions I should be ok.

The only part about the job that would frighten me would be a valve job. it seems pretty complicated. Is it necessary that I do this. I mean I probably wouldn't hurt, I am just concerned about the tools I would need to do the valves. I really want to clean this thing as much as possible.

I am already concerned about putting this much back together.

Please share some experience and if there is anything I should definitely do at this point. should I degrease and rinse all the internals as well as the externals. Where can I and can't I get water. what kind of cleaner should I use, things I should look for ect.

Here are some pics to enjoy too.

Thanks Everybody!

Justin

[Burk Ferden]

Pics

In the frame

[Burk Ferden]

Pics

Out on the floor...

[Burk Ferden]

Pics

Empty frame...

[49er]

Now you've done it!

Hi Justin,
You don't need to remove the engine from the bike to do the repairs that you are doing. However, now that it's out, it will be a lot easier to work on.
Prepare an area where you can lay out all the engine components as you dissassemble. It is important that that you identify components so that they are fitted in the some place on the engine at reassembly time. Examples are matching pistons to the correct bore, valves and valve buckets to each chamber, etc.
I use kerosine as a cleaning agent in a shallow bath (an old 20 lt steel drum cut in half length ways). There are other agents that work well. Kerosene is easier on the hands.
Clean all parts separately to avoid mis-identifcation, then lay them out on clean newspaper. You can write any identifcation number/letters next to them to help your memory. When you have completed the cleaning exercise, cover the components with clean rags or old sheets to keep any dust off them until assy. If you need to leave the parts for an extended period before assy, lightly lubricate all steel components with oil to prevent rusting.
Order a complete gasket set. I use Vesrah and have had good results with them. Its cheaper to get a complete set, than just trying to replace the top end gaskets. You need to look at replacement seals for the cam chain tensioner and the tacho drive. These are not included in the main set.
Check the condition of your breather tract inside the airbox. If its blocked, it will be causing most of your oil leaks through poor crankcase ventilation.
Keep asking questions as the need arises.

[Burk Ferden]

Well removing the engine was easy. We got down to the cylinder block and decided to replace the top mid and base gasket. The hardest one to get off was the base gasket. It must have just baked on there from all the years of starting and stopping. I cleaned a lot of the carbon off the piston heads and the cylinder walls look like they are in great condition. Tonight we are going to scrub it, put the new base gasket on and slide the cylinder block back on. Then add the mid gasket, and clean the cylinder heads.

I got new gaskets for almost everything on the engine, it included valve seals. That section scares me a little. From what I read the cams are easy to install and time, but I am unsure about the effort in doing the valves.

What you guys think. Valves or no Valves.

On with the pics...
The Piston Heads

My box of goodies

Looks like the color was black, then orange then black, then grey...

Cleaning off that nasty base gasket

[Kcwiro]

Here is a tip for cleaning the base gasket material... a very soft metal brush wheel mounted on either a drill or dremel will make it a lot easier on your hands for cleaning off the junk... I did this on my head and cylinder block and I got excellent results... if you don't want to pull your engine studs out the dremel is goot for the hard to reach places around them... it also helps to spray metal cleaner on the parts as you are using the wheel so you don't scortch anything.

Your pics bring back a lot of memories from when I was rebuilding my engine...cept I left mine in the frame since i left the crank and bottom part alone...

hope this tip helps you out...PS... the circlips that hold the wrist pins in ... don't let those guys pop out... they can take an eye out so wear eye protection... and keep a magnet stick handy just incase they fall into your oil PAN... but you should be cleaning that pickup screen out in that guy anyway if your not doing your oil pump...mine has a mechanical one that is pretty solid so I left that much alone...but that screen.. YUCK!

Just a FYI hope this information helps you...GOOD LUCK:-D

[80GS1000]

What method did you use to take the engine out of the frame? I'm about to do this myself and would appreciate any tips you might have. Thanks in advance.

[Burk Ferden]

Make sure that all electrical is disconnected. There is a sneaky ground wire between the swingarm and the gearbox. jack up the bottom of it, or just stack some wood underneath.
Remove the pegs, it makes it easier, remove clutch arm, rear brake, and gear shift leaver, and spark plugs. Remove the motor mount bolts. Some of the motor mount bolts go straight through, I just used a dead blow on the threaded end and a pair of vice grips wrapped in tape on the head and yanked them out. once all the bolts are free, tilt the engine forward and it should come out the right side (as if your sitting on the bike). Definitely a 2 man operation. You might have to temporarily zip tie the spark plugs and cables up to the frame to keep them from hitting the breather hose cap.

Let me know how it goes. Once again love the bike!

Justin

[catbed]

what are those springs in the top left of the box? i have an 83 850 and i dont see those. am i blind?

[Burk Ferden]

Those are the clutch springs. I took them out to replace them because the clutch was slipping so bad. Hopefully they come today.

[catbed]

whew...... thought they were from the top end.

[Burk Ferden]

HAHA. Yeah I think it would be a bit interesting if you took apart your cams and put them back together only to realize later that you were missing some stuff

[stroka]

Hi, I'm about to change the head gasket on my '82 GS650G and had a couple of questions.
The bike actually has only ~ 15,000 miles on it but it started to leak oil last fall right after I bought it. I decided to change the oil first and poured out almost 8 quarts of oil!!! But even after changing the oil it still leaks quite a bit (it feel like especially on colder days). It is second time on this forum I read something about good ventilation through the airbox. Would it be a fix for me?

If not, I was wondering if it is really necessary to remove the engine from the frame for changing the head gasket?
Do I need to change a base gasket too? I'm new to bikes and never completely took engine apart before all by myself.
What else should I look for to do while I'm doing all this?
Thanks!

[stroka]

One more picture of the leakage from '82 GS650G