Burned oil, then stopped?

[Guest]

Check this out. Was riding home, 2am, and went over the mountain. The temp was around 25 on top for about 50mi.. No problem noticed at the time.. The next morning I find oil was way low,(below sight glass, and was full when I headed out the night before). Smoked hard when started, and still a little when hot. I was thinking I blew a valve guide in the cold, and walked away thinking of doing the top end.. It sat a week with me on the road working, and when I get back she is not smoking at all, not burning any oil, whatever it was just went away!?? Any thoughts? lol

[recycled64]

If you 'went over' the mountain, you had to come down, and if you spent a lot of time on decel, could be that the top end filled up with oil, and if it was a short (ish) ride to home from there, it probably stayed up there for a while, a week of sitting might have drained the oil back down to the crankcase. Just a thought.

[Agemax]

valve guide seals

[koolaid_kid]

If it is valve guide seals it will also smoke when first started after sitting overnight.

[Agemax]

If it is valve guide seals it will also smoke when first started after sitting overnight.

not always....

[JSP]

valve guide seals

Thought crossed my mind that if they are cracked and shrunk up when that cold, allowing to burn off, then after sitting at warmer temp its closed back up.. Right now there is no smoke on cold start, and has not needed any oil after this happened lol I guess I will start getting ready to do the top-end, if not a total rebuild... Thanks Agemax..

recycled64,, Possible, but.. Don't ya think if the top-end was full of oil, at that kind of pressure, I would have some signs of leak from the valve cover? I have no leaks on this motor. What ya think? Looks like either way I need to look at doing the top-end at least.. 30yr old motor so I'm giving thought to a total rebuild...

Koolaid,, I'm going to watch real close for a bit but so far its not smoking on cold starts, or so little it's hard to see.. Just the morning after that ride did it smoke hard. Oh, and I ride in the cold up on the mountains, quite a bit.. Coldest was Grapevine at around 15 above. lol I like to ride!

**UPDATE** I stand corrected.. She just smoked for 15sec on start, in shade at 65...

[tom203]

I've noticed 1/4 inch variation in sight glass from time to time- looks low then next day it's back at mark. Might be oil hanging around in top end, but could be oil not flowing back from secondary drive cavity for some reason at times. ignore it like I do!

Edit; my 650 at 44k burns no oil, leaks no oil, so I'd avoid top end work until you're sure (or bored)

[Steve]

Thought crossed my mind that if they are cracked and shrunk up when that cold, allowing to burn off, then after sitting at warmer temp its closed back up. ...

Once the engine gets up to full operating temperature, there is virtually no change in the temp at the seals, whether you are in 25 degree weather or 95 degrees.

Don't ya think if the top-end was full of oil, at that kind of pressure, I would have some signs of leak from the valve cover?

Does not matter how full the top end is, there is NO pressure up there. After oil squirts out from the cam bearings, it just puddles there until there is enough to spill over to the cam chain tunnel, and it just runs down.

Looks like either way I need to look at doing the top-end at least.. 30yr old motor so I'm giving thought to a total rebuild...

How many miles on the engine? Might not need a "total rebuild", just some new gaskets.

Unfortunately, the easiest way to replace the valve seals (your most-likely culprit at this time) is to remove the head. Removing the head also disturbs the cylinders, so you should replace the base gasket, too. Don't mess around with aftermarket gaskets for these, get OEM Suzuki gaskets. They cost more, but you will only have to do them ONCE.

By the way, we have no idea where you are. For our friends north of the border, 25 degrees is some nice riding weather. For those of us on this side of the border, it's downright CHILLY. Please take a moment and update your profile to show your (approximate) location. As you can tell from my location, you don't have to provide a street address, but even a hint can help a lot.

.

[JSP]

Thanks Steve! I have been told that the minor high rpm vibration I have is the mains.. That's why I am thinking about top and bottom end. Any input?

Once the engine gets up to full operating temperature, there is virtually no change in the temp at the seals, whether you are in 25 degree weather or 95 degrees.



Does not matter how full the top end is, there is NO pressure up there. After oil squirts out from the cam bearings, it just puddles there until there is enough to spill over to the cam chain tunnel, and it just runs down.



How many miles on the engine? Might not need a "total rebuild", just some new gaskets.

Unfortunately, the easiest way to replace the valve seals (your most-likely culprit at this time) is to remove the head. Removing the head also disturbs the cylinders, so you should replace the base gasket, too. Don't mess around with aftermarket gaskets for these, get OEM Suzuki gaskets. They cost more, but you will only have to do them ONCE.

By the way, we have no idea where you are. For our friends north of the border, 25 degrees is some nice riding weather. For those of us on this side of the border, it's downright CHILLY. Please take a moment and update your profile to show your (approximate) location. As you can tell from my location, you don't have to provide a street address, but even a hint can help a lot.

.

[JSP]

I've noticed 1/4 inch variation in sight glass from time to time- looks low then next day it's back at mark. Might be oil hanging around in top end, but could be oil not flowing back from secondary drive cavity for some reason at times. ignore it like I do!

Edit; my 650 at 44k burns no oil, leaks no oil, so I'd avoid top end work until you're sure (or bored)

Thanks Tom! I will be monitoring it for a bit. I'm not tearing it down next weekend

[tkent02]

Ride it. A lot.

[JSP]

Ride it. A lot.

I do when I am in town.. Have not drove my car any real distance in months. Always on the bike hehe

[bwringer]

You can replace the valve stem seals without removing the head -- use an air hold to keep the valves closed. Remove and replace the valve keepers by rigging up a lever to compress the springs, or use the special tool that you strike with a hammer. Not the most convenient, but it's possible.

[tkent02]

Someone on here did it by using a rope fed into the spark plug holes to keep the valves closed.