The oil is commonly recommended to be 20w-50.
Some people like to use 10w-40 in the winter, if it's cold.
Synthetic oil should not be used until after the break-in period is completed, if you want to start using it.
The oil is changed by removing the all the drain plugs on the bottom of the engine.
The reason that I say "all" is because the number of drain plugs down there has varied over the years, and some have more plugs than others.
There is normally one for the front oil gallery, with a screen piece inside, a similar one for the rear oil gallery with a screen, and sometimes there is one on the oil tank, and sometimes there is one in the sump floor.
If you remove the ones under both oil galleries, you'll get a full drain of the engine cases.
Here's how to tell the oil gallery plugs. There are some semi-tubular "humps" in the engine casting which are vertical. These are located right by the oil pump cover locations on the timing cover, because these oil galleries feed the feed pump and the scavenge pump.
So, look down under the bottom of the engine below where each oil pump cover is, and there should be a plug down there that corresponds to each oil gallery.
When you remove those plugs, there will(should) be screens inside that are attached to the plugs. These are grit screens that stop huge boulders from entering the oil pumps. Try not to mix them up. They should be returned to the holes that they came out of.
After you drain the oil, you may CAREFULLY screw the drain plugs back in.
This is soft ALLOY. It is very easy to strip these drain plug threads, and then you have a problem. So, all they need to be is tight enough to seal, and not vibrate out. About 7 foot-pounds is all they need.
If one ever gets drippy, do not crank the plug in harder.
Just get a new crush washer and install the plug at normal tightness, and it will stop the leak.
Now, at this point, the only part that hasn't been drained is the timing chest.
This doesn't have a real drain on it.
You can either remove the whole timing cover to get the oil out, or you can pull the quill bolt and get some of it out, or you can just leave that old oil in there and not worry about it. It will get mixed around with the new oil anyway, and if you change often enough, it won't be a problem.
Personally, I leave the old oil in the timing chest, because it's not worth it to me to risk pulling off the timing chest or quill, and risking damage to anything in the process,when I don't really have to do it. I simply change my oil often enough to overcome that issue.
To replace the filter, just unscrew that nut on the filter housing to take the cover off of it. The filter is a cylinder shaped cartridge inside that slides right out. It's messy.
Clean out the filter chamber as best you can to remove sludge and deposits.
Soak the new filter cartridge in new oil for about an hour before installing, and get it good and soaked with oil when you put it in. That will fill the filter chamber pretty good with oil, so that you don't have to wait 5 minutes for the oil to fill up the chamber with the pumps, while starving the crankshaft of oil.
Put the cover back on.
After you do whatever draining you are going to do, and have changed the filter, and replaced all plugs and covers, then fill the oil tank to about 3/4 full on the dipstick.
At this point you could start the engine, or you could put the bike in top gear, open the decompresor, and walk the bike around the driveway or street for a few hundred yards. This will move the oil around in the engine oilways, and it's not too hard to push the bike in gear with the decomp open. That primes and fills all the oilways,so that oil is all around where you need it when you start it up.
You don't "have" to do that, but it will help the engine life if you do, because most engine wear comes from cold starts, and especially after oil changes when there wouldn't be any oil available to the critical parts for up to a couple of minutes after you start it up.
After you run it enough to be sure that it's circulated all around the engine well, check the oil, and is probably a bit low. Top it up to halfway on the dipstick, or maybe even back up to 3/4 full. It doesn't need to go all the way up to full.
Then you're good to go.
The gearbox on a 4-speed doesn't get its oil changed. It's grease.
The proper topping-up method is to remove the level plug from the front end of the gearbox, which is about halfway up the gearbox on the front. If anything drips out, it's full. If nothing drips out, it needs topping up.
The topping up plug is on top of the gearbox near the top of the cover plate.
Take that out, and use 50w engine oil to top it up until oil begins to run out of the level plug. Then it's full.
Replace plugs.
On a 5-speed, it's similar, except it has gear oil of about 90wt or thereabouts to be used in it. You can change that too, if you have a 5 speed, but I think you have a 4 speed, so I focused on that.
The primary oil is generally 20w-50 too.
There's no drain.
You just take out the main nut that holds on the primary cover, and it all drains out all over the place. It's good to have a large pan under it that is bigger in area than the whole primary case, because it comes out everywhere.
Then clean it up, check your primary chain adjuster, and put the cover back on.
Fill it up via the filling plug with about 420ml of 20w-50 engine oil, and you're done.
Don't crank the snot out of the nut that holds the primary cover on. If you get a leak, take off the cover again and make sure the gasket is on right, and put the cover back on.
If you over-torque the primary cover nut, it will distort the primary cover permanently, and it will NEVER seal the oil in.
The general pattern here that you see developing on this bike is don't over torque anything. It's all aluminum. As tight as is needed, and no more than that, is all you want.
Topic: Fluid Changes (Read 1045 times)