Topic: Where did all my oil go?

[jimbojangles]

Hey guys,

Got my 350f up and running after a 20+ year slumber. It idles great and runs pretty smooth. The weather was finally nice enough to take it for a spin and all went pretty well. However, I did notice upon my return that there is some white smoke coming from the exhaust and breather tube. It's worse when the engine is hot. It's not really bad, but it's enough to cause concern. I'm assuming I have a stuck ring or two and am burning a bit of oil. I've read the forums here and will try some sea foam and a good long ride.

My other problem is that I don't know where all my oil went. I checked the oil level and it isn't showing any on the dipstick. There aren't any leaks and I know the smoke isn't bad enough to have burnt that much oil in a 10 mile drive. This is my biggest worry. I don't want to add more oil and overfill it, but I don't want to run it low like it is. Is it possibly that all of the oil is somehow stuck in the top end somewhere?

[Trad]

Add oil until it shows on the dipstick. It's not all stuck up top. Make sure the bike is sitting level when you check.

It sounds like rings for sure if it's burning up that quickly. You valve guide seals are probably not helping either.

You can try seafoam but there is no replacement for a hone and re-ring id all is still in spec.

Hope that helps.

[ADW]

My 350F ended up blowing white "smoke" out the overflow/road tube when I first ran it after sitting for a long time when I first got it. It was/is just condensation and will burn off once you get the bike good and hot and ride it for an hour. So, since it sounds like this was your first ride after it sat for a long time I'd say don't worry about the white smoke just yet...see if it goes away as I mentioned. I'll betcha it'll be gone next time you check if you take her for a good long ride and get her up to temp. (Check your oil before you go!)

One thing regarding checking your oil: you do know that on Hondas you do NOT screw in the dipstick to check it, right? Unscrew the dipstick, wipe it off, then set it back in the hole but don't screw it in. Now pull it out and check it. (This wouldn't have any impact on your "where's my oil" issue, just wanted to mention it while we were at it). And Trad is correct that you need to make sure the bike is level when you check the oil, if it's on the sidestand it's going to be pooled up on the LH side of the case, away from the dipstick.

[jimbojangles]

Thanks for the replies. I'm going to pull plugs tonight to check for oil fouling. I really thought it was just condensation myself for a few reasons, but my vanishing oil made me think otherwise. I'll see how much oil it takes to bring it back to spec. It sat without oil in it for quite some time before I got it, maybe it was thirsty.

I'm leaning toward/really hoping it's water vapor for a couple of reasons. 1st - water was literally dripping out of the motor the first time I started it. I thought the whole thing smelled like cat piss the first few times I ran it. (Maybe that was the water boiling off.  2nd, the smoke is worse when it's hot. I figured a leaking valve seal would smoke more at start up since the oil would have time to leak down into the cylinder.

I know people say that white smoke is water and blue smoke is oil, but for a guy who is partially color blind I can't tell a bit of difference.

[Davez134]

For what it's worth, by bike had similar smoke/condensation symptoms after repeated short rides/sitting.  As others have said, a few long rides should clear that up. Does your  350 have the stopper valve in the oil pump like a 750? Could the oil have seeped down into engine? Or is this not a dry sump system? Sorry don't know a whole lot about your model.

[AintNoEasyWay]

I had a similar problem with my 750, but also had an oil/gas mixed leak out of my exhaust & from my head gasket. My issue could have been a combination of bad rings, valve stem seals, & old head gasket leak. I'm redoing the whole top end now & hope that will remedy it all.

[jimbojangles]

Hey guys. Thanks for the replies.

The 350f is a wet sump, so luckily for me I don't have to deal with an oil tank.

I only had time to check a couple of things last night, but I'm optimistic that I won't have to take the motor apart.

I was about a quart short on oil. I still don't know why this could be other than it was a bone dry motor and the level dropped once oil was circulated to the transmission and filter housing.

I checked all the plugs and there wasn't any sign of oil on them. They all looked great except for one cylinder that is running rich.

I'll go for a long ride this weekend and report back.

[strynboen]

if you are running "old oil"..it can be 50 % fuel and vater mixed up vith the oil..and vhen running the engine hot the first tine it all vauper/goes to damp.
.so thange oil before run a old bike..
vhen i bayed my cbx..it have stayed for some years...and i had to run it home on the old oil...the level vas fine ,,,but after 200 kmt it alll vas gone...and i have to afterfill,,just to get home....after a thange..i dont have vaste of oil..
so dont run a new old bike a long vay home...trail it..and thange oil and filter before testrunning

[MCRider]

I had a similar problem with my 750, but also had an oil/gas mixed leak out of my exhaust & from my head gasket. My issue could have been a combination of bad rings, valve stem seals, & old head gasket leak. I'm redoing the whole top end now & hope that will remedy it all.

If the problem was low oil level in the tank, could've been leaking down past the oil pump into the sump. So called "wet sumping". Rebuild of oil pump on our old geezers becoming common place as the rubber stopper seals are fagging out.

[jimbojangles]

It's been a while, but work has been busy.

I think I'm safe from needing a rebuild this summer. I'm no longer sending white smoke out of the exhaust anymore and have put a couple hundred miles on the bike. Oil level is also remaining consistent. I think the problem was a loose spark plug cap that was causing weak/no ignition on one of the cylinders. That was sending unburnt fuel into the exhaust. I likely had some sticky rings too.  Now the bike runs great and doesn't smoke.

I do have two concerns though:

1. I'm still getting white smoke/condensation out of the breather hose. I can't tell if it's oil or gas by smell, but it is flammable! I've read that the 350fs didn't have valve seals on the exhaust valves. Could this be the reason for this?

2. I've noticed a whining sound from the lower front end of the motor when it gets hot. This only happens at lower RPMs. Any ideas on this?

Thanks.

[strynboen]

if you have teighten the cam thain to hard.(.normaly imposibel)..its start "vining"..it vill eat the tensioner in short time..its only if you force the bolt by press it direkt..this can happend.
.normaly it are to Loose..and rattel hard by idel...