Gas in Oil

[Buffalony]

So I had this problem come up in another thread and another member is having the same issue.
http://www.ninjette.org/forums/showthread.php?t=77854


I'm trying to narrow down the source of the gasoline.

I've come up with a few possibilities, but had some questions about something interesting I've just come across in the service manual.

Back ground.

Not too long ago I posted a question up about my air filter smelling like gas.
http://www.ninjette.org/forums/showthread.php?t=60805

All was good and left it alone.
Today I pulled the filter and noticed it had quite a bit of oil on it this time.
later I was going through the service manual and noticed on page 99 Section 3-25, that there is an oil drain plug at the bottom of the air box, left side of bike! Never knew of this one

I did know that there is a crank case ventilation tube that connects to the bottom of the airbox from the top of the crankcase so crankcase vapors can be burned of in combustion.

My question comes from not being able to see how these tubes are positioned with respect to each other.
I'm wondering if because my oil drain in the bottom of the air box is likely full, is it possible for any fuel introduced into the airbox for whatever reason could be floating on top of that oil and down through the crankcase vent tube into the case contaminating my oil?

A reply from anyone who knows the inside and bottom of these boxes would be greatly appreciated. TIA

[whatitstrue]

Originally Posted by Buffalony

I'm wondering if because my oil drain in the bottom of the air box is likely full, is it possible for any fuel introduced into the airbox for whatever reason could be floating on top of that oil and down through the crankcase vent tube into the case contaminating my oil?

A reply from anyone who knows the inside and bottom of these boxes would be greatly appreciated. TIA

First There shouldnt be fuel in your air box for any reason.

As to your Question... is it possible? Well most thing are possible, but having said that...Short answer no.

[whatitstrue]

Id also add that the blow bye can and will vent back into the case but you would need a large amount of gas flowing back in there to cause any desernable issues.

Why do you think there is fuel in your air box? fuel evaporates fairly Quickly youd have to be dupming some large amounts in there. The bigger issue would be how is fuel getting in there and why its not evaporating or being sucked back in to the carb if it was???

[venmichaels]

i def have gas in my crank case it smells very strong.. im really dissappointed and i have no money to repair it..

[DaBlue1]

Originally Posted by venmichaels

i def have gas in my crank case it smells very strong.. im really dissappointed and i have no money to repair it..

You may have to a least, change the oil yourself.

[Buffalony]

Originally Posted by whatitstrue

Why do you think there is fuel in your air box? fuel evaporates fairly Quickly youd have to be dupming some large amounts in there. The bigger issue would be how is fuel getting in there and why its not evaporating or being sucked back in to the carb if it was???

I had a problem with fuel in it back at the end of last year. There was definitly fuel in it. When I pulled the filter then, it was soaked in gasoline.

Yesterday when I checked the air filter, the bottom left of it was soaked with oil, but i dont think it smelled of gas.

The air box oil drain cap is higher than the crankcase vent tube. I don't know how or if they are seperated inside the housing. I'm asking if someone who knows the inside of this box can tell me if it is a possibility for the space connected to the drain cap to overfill and spill back into the crankcase?

I just went out with a flashlight to triplecheck this before i posted. The flashlight just showed me that I can see into the cap and it does infact have oil in it. Yesterday I thought it was just a black cap.

So far i'm thinking I might have a float problem. Sucks Ill have to change the oil. I just did a change 600mi ago!

[DaBlue1]

The air filter itself is lightly saturated in oil. Over time the oil in the foam will migrate down and to the left. So from time to time you need to inspect, clean and re-oil the filter. The oil in the filter asks as a sticky medium for small particles.

If you've ever heard a poof or pop at start up but it did not sound like it came from the exhaust, it was probably a carb spit back. That's where the gas will actually spit gas into the airbox instead of the piston chamber. So it is possible for gas to get on the filter.

[whatitstrue]

Originally Posted by Buffalony

I had a problem with fuel in it back at the end of last year. There was definitly fuel in it. When I pulled the filter then, it was soaked in gasoline.

Yesterday when I checked the air filter, the bottom left of it was soaked with oil, but i dont think it smelled of gas.

The air box oil drain cap is higher than the crankcase vent tube. I don't know how or if they are seperated inside the housing. I'm asking if someone who knows the inside of this box can tell me if it is a possibility for the space connected to the drain cap to overfill and spill back into the crankcase?

I just went out with a flashlight to triplecheck this before i posted. The flashlight just showed me that I can see into the cap and it does infact have oil in it. Yesterday I thought it was just a black cap.

So far i'm thinking I might have a float problem. Sucks Ill have to change the oil. I just did a change 600mi ago!

yes fluids can drip back down in to the crank case through the vent from the air box. the oil your seeing in there is either from the filter or blow bye from the crankcase vent. its no big deal.

And I hear what your saying, but the fuel is not flowing from your air box in to the crank case. There is no way the fuel could get in there to drain down.


Definently on the right track checking your floats.

Good luck and let us know!

Originally Posted by DaBlue1

The air filter itself is lightly saturated in oil. Over time the oil in the foam will migrate down and to the left. So from time to time you need to inspect, clean and re-oil the filter. The oil in the filter asks as a sticky medium for small particles.

If you've ever heard a poof or pop at start up but it did not sound like it came from the exhaust, it was probably a carb spit back. That's where the gas will actually spit gas into the airbox instead of the piston chamber. So it is possible for gas to get on the filter.

Also known as a carb fart. it can happen on light acceleration. Ussualy caused by a lean condition.

[venmichaels]

im about to change my oil... Is there a definite way to spot gas in the oil that i drain out besides just smelling it??

[kkim]

not that I know of, other than sending it off to be analyzed.

[DaBlue1]

Originally Posted by venmichaels

im about to change my oil... Is there a definite way to spot gas in the oil that i drain out besides just smelling it??

In your other post, you stated that you did not use the clutch on start up, correct? So I'm assuming that start ups were a little slow and sluggish, engine idle slow, compression low and engine temp low....I'm i right so far?
to compensate you probably twist the throttle to bring the engine speed up until it is warm enough to idle properly by itself. I think most people here would think you have a typical flooding problem.

Basically you are putting too much gas into a cold engine and it is not all being burnt, but that is a small amount. I'm willing to bet that if you change your starting procedure, ride the bike normally, let the bike cool all the way down then recheck the oil to see if it smells like gas, it will probably smell more like used oil should. If the mechanic that looked at you bike did not notice a strong overwhelming odor of gas at the time he looked at, he probably could not smell it. When gas fumes are overwhelming enough to make you lightheaded it is usually very fresh, meaning like just poured. If that was the case I'm pretty sure anyone within 3-5 feet would smell you too and it would be visibly noticeable.

Here is a test you can do; once you drain the oil smell it then smell some fresh gas, put both aside. Don't put oil back in the bike right away, flush out as much old oil as possible and remove the filter as well, let it sit for a while to see if gas may possibly be leaking past your petcock, carb floats and into the crank case. Also remove the airfilter, clean the filter and dry out the airbox. If the carb is going to leak that much gas in to the crankcase it will leak just as much into the air box as well. Visible leakage will be noticeable and the smell of gas will be strong as well in both the airbox and any remaining residual oil in the crankcase. Note the amount oil oil that comes out of the crankcase. If you have more than 1.7 qts of you come out, it was too full, and if there is a large amount of fuel in the oil it will be very noticeable by smell.

[Buffalony]

thanks Rich. I'll be pulling the carbs this week to check those floats.

[whatitstrue]

Blue while agree most likely his issue may be as simple as poor start up procedures.

If it is beyond that then yes the 2 things buffalony should start with would be the floats and petcock.

Not that it matters, but I still have to disagree about the fuel making it to the airbox... Say hes getting exsesive fuel via the floats or faulty petcock theres only 2 places it can go. Out the carb overflow or thru the intake ports and into the cylinders. As theres a lip on the air box which is higher than the intake.

Small amounts of fuel into the cylinders is bad it causes cylinder washdown and large amounts of fuel can move past the top of the cylinders and into the crankcase (wich breaks down the oil).

The only way fuel could make it to the airbox is if it came from the crankcase vent not the carb, on start up or something.

[Buffalony]

Originally Posted by whatitstrue

Blue while agree most likely his issue may be as simple as poor start up procedures.

If it is beyond that then yes the 2 things buffalony should start with would be the floats and petcock.

Not that it matters, but I still have to disagree about the fuel making it to the airbox... Say hes getting exsesive fuel via the floats or faulty petcock theres only 2 places it can go. Out the carb overflow or thru the intake ports and into the cylinders. As theres a lip on the air box which is higher than the intake.

Small amounts of fuel into the cylinders is bad it causes cylinder washdown and large amounts of fuel can move past the top of the cylinders and into the crankcase (wich breaks down the oil).

The only way fuel could make it to the airbox is if it came from the crankcase vent not the carb, on start up or something.

Thanks Rich. I am thinking im getting extra fuel blowing by the rings. But that oil drain is full on the airbox. I'll be pulling the carbs and the tank thursday. I'll also be ripping the airbox apart to get a better look inside.

Can anyone tell me if it is safe to just remove the vent tube, install a crankcase vent filter and plug the airbox connection?


My worst fear is that my rings didnt break in right But I'll check everything before coming to that conclusion. I'll admit that I dont do anything to the bike for winterization besides put it on a trickle and start it every 3-4 weeks. I think thats likely the culprit here (fingers crossed). I have some stainless parts for the carb on order from desmosparts (2nd time ordering same parts!!). Im hoping they arrive soon. I'll update thread accordingly.

BTW. I believe the main contributor to the gas in my airbox last year WAS poor start up procedure. I would use the choke to start and forget to turn it off. I havent had to use the choke this summer at all? I will also be checking the choke adjustment while im in the vicinity.

Thanks again all. Miguel. How you doin?

[kkim]

if you're concerned about ring condition, have a compression check done.

are you seeing any oil level rise in the crankcase sight glass? if not, I don't think you're having appreciable gas in the oil to warrant worrying about it. Have you been riding the bike much? maybe all it needs is an oil change and a good hard ride?

[Buffalony]

Originally Posted by kkim

if you're concerned about ring condition, have a compression check done.

are you seeing any oil level rise in the crankcase sight glass? if not, I don't think you're having appreciable gas in the oil to warrant worrying about it. Have you been riding the bike much? maybe all it needs is an oil change and a good hard ride?

Compression is now on the list.

No. I dont think the oil is rising. good observation though. Ill have to keep an eye on it.

I've been riding alot.

just changed the oil 600 mi ago.

Does your gas smell like oil??

I pulled the tank and so far the petcock/tap is good

I drained the bowls and there was some very small aluminum shavings in them and some other small junk. I'm gonna have to do a better job winterizing this thing this year!!

I havent pulled carbs yet but I'm workin on it now. I expecting the jets to be ugly but not clogged.

I also checked both plugs and they were at the low end of the gap spectrum. I scraped them and gapped to .035" torqued and capped. The right plug had some white chalk like residue around the nut side of it. Should this worry me?

[kkim]

Originally Posted by Buffalony

Does your gas smell like oil??

dunno... haven't made a habit of smelling my oil, though when I change it, it doesn't smell overly of gasoline.

I drained the bowls and there was some very small aluminum shavings in them and some other small junk. I'm gonna have to do a better job winterizing this thing this year!!

hmmmm... that's odd. filter in the tank and in the fuel line. wonder where the aluminum is coming from? shiny aluminum or whitish corroded color?


I havent pulled carbs yet but I'm workin on it now. I expecting the jets to be ugly but not clogged.

what makes you suspect that?

I also checked both plugs and they were at the low end of the gap spectrum. I scraped them and gapped to .035" torqued and capped. The right plug had some white chalk like residue around the nut side of it. Should this worry me?

most likely just some water residue from you washing the bike. water can get down into those towers. there are 2 holes on the front side of the engine that lets the water drain. maybe one of them is plugged and allowing water to build? miles on bike?

[Buffalony]

Originally Posted by kkim

hmmmm... that's odd. filter in the tank and in the fuel line. wonder where the aluminum is coming from? shiny aluminum or whitish corroded color?

Shiny nonferrous. I just picked up a small inline filter yesterday to install before the carbs. Its not a clear one though. I think I'll check the tank filter while its off? Is there a gasket/sealant needed for reinstallation?

Originally Posted by kkim

I havent pulled carbs yet but I'm workin on it now. Im expecting the jets to be ugly but not clogged.

what makes you suspect that?

I never winterized anything for the past two winter seasons. I only start it a few times out of and average of 5mos. of storage. Also, when I drained them there was a tiny bit of junk in each. In that I spotted a very tiny ring of gunk. I think this was from a jet but I could be wrong. Might've been from the inside top of the bowl drain? But it looked too small for that.

Originally Posted by kkim

most likely just some water residue from you washing the bike. water can get down into those towers. there are 2 holes on the front side of the engine that lets the water drain. maybe one of them is plugged and allowing water to build? miles on bike?

I figured as much. I didnt know there were drains for those Cool. I'll check them. I also put a light coat of HD grease on the boot rings. ~5200miles

Looking at the oil through the sight glass, it appears to have a greenish tint to it and looks a tad milky on the top. The oil only has been in for 600miles.

[kkim]

Joe,

maybe I missed it, but are you presently having any idling/engine/running problems other than suspecting gas in your oil? how's your MPG?

[Buffalony]

Originally Posted by kkim

Joe,

maybe I missed it, but are you presently having any idling/engine/running problems other than suspecting gas in your oil? how's your MPG?

So far this year I havent had to use the choke to start from cold. I checked the cable and adjustment and all was good there. I just assumed its because of the summer heat.

Also my idling has been sorta erratic. I adjust it at a light, rev it to make sure it returns well, then the next stop it'll go too low. Example, I'll adjust to 1300-1400 rpm then ride, then next stop it might be less then 1100. Not necessarily next stop but later. Sometimes it'll be higher like 1500. Sometimes it'll dip later. It just goes back and forth from time to time. Again, probably normal for a naturally aspirated right?
EDIT: forgot to add that I checked both throttle cables and theyre good. return is good.

I havent been paying much attention to fuel consumption. Sorry. We get such great mileage with our bikes

The oil reeks of gasoline though. I have new oil left in the container and used it as a smell reference and the bike oil it is quite smelly in comparison. The oil in the case is a greeny dark brown. Its mobil1 synth.

The bike has been riding like a champ. Now, I have been riding with 325lbs of load on it. Just started with a passenger this year. Maybe this had some kind of effect, but I'll add that since the oil change 600 mi ago I have only rode maybe 50miles of that with the passenger. We did alot of riding together before the oil change. When I changed the old oil it didnt smell anything of fuel. Infact I still have it.

The other thing I did on this new oil was threw on my muffler project, made a vid and test drove it. I beat the poop out of it that night for maybe 5 minutes. I had a flame shoot from the exhaust when doing the vid if that means anything. No back firing on decel in that short five mins.
I was reving the bike oddly for the video. I wonder if that contributed in anyway.

[kkim]

it does sound like you may have some clogging going on in the idle circuit. try some seafoam in the gas... speaking of gas, you do have fresh gas in there now, right?

with regards to smelling gas in the oil... what's your jetting specs? if you had richened it up before and then put the homemade can on it, perhaps now you're too rich?

[Buffalony]

Originally Posted by kkim

it does sound like you may have some clogging going on in the idle circuit. try some seafoam in the gas... speaking of gas, you do have fresh gas in there now, right?

with regards to smelling gas in the oil... what's your jetting specs? if you had richened it up before and then put the homemade can on it, perhaps now you're too rich?

I know they are too lean from the factory. I havent touched the jets. The muffler night was my first ride test. So I really didnt expect a richer condition from just adding the muffler. I must say that there werent any dead spots when I took it for a ride that night. It just felt really good all over. Or maybe that was just because of my excitment Honestly it felt good through WOT. Which also makes me think something is going on in there.

As of right now the bike is stock. I'm about to pull off the bowl covers right now and try again to figure out how to measure the floats and clean/soak everything. I picked up some kerosene.

[kkim]

you are correct, the factory jetting is lean, so if you still have stock jetting and then added a can, that would have made it even leaner. I was hoping/thinking you had already futzed with the jetting.

[Buffalony]

Is it normal for the tips of the idle mixture screws to protrude into the carb outlet chamber in front of the butterflys? One is and one isnt

Im gonna remove the caps now.

[kkim]

no idea, but they should be set to...

Pilot Screws (turns out)- left- (2 1/2) right- (1 3/4)

[Buffalony]

Originally Posted by kkim

no idea, but they should be set to...

Pilot Screws (turns out)- left- (2 1/2) right- (1 3/4)

Thank you. was my next question.

Left as in cylinder1 sitting on the bike right?

[kkim]

Originally Posted by Buffalony

Left as in sitting on the bike ?

correct

[Buffalony]

So far I've found a tiny little piece of debris stuck on the cylinder bore of the right carb. It was position in a way that prevented the butterflys from closing all the way. It was a good size about twice the size of a period.

Also, when I went to turn in the right pilot needle in to count where the factory had them, I barely turned it and it popped up into the bore about .80"!! whats up with that? I know they have springs, but are these supposed to move around during operation? I only started turning it and it popped right up.

I really appreciate it.

[kkim]

dunno what's "normal" with the mixture screws (that is what you're talking about, right), but did you count the number of turns they were set to? also, they are tapered (I think), so sticking up may be perfectly normal.

edit... look at this pic... might be normal for it to be sticking up? this is on stock carbs...

[Buffalony]

The right was at 1 3/4 almost exactly!! it does protrude a little into the bore.

The left one: At first inspection, it was below the bore. I couldnt see the tip.
When I turned it to tighten it, to figure out how many turns it was set at......Within 1/8 of a turn it popped up into the bore.

What I believe happened is the rubber O-ring was bound up in there from installation and when i tightened it, it sat correctly causing the taper to protrude into the bore ALOT. It literally went up about 3/32nds of an inch.

I'm hoping this didnt screw up my sync too much??

Float bowls were set at spec exactly! er well...with in .010 out of .080 tolerance.

Everything looked clean except one of the two little holes on the air box side intakes had a chunk of what looked like the stuff they used for the airbox seal material. That brownie looking glue. The holes are the ones drilled on the curved surface. btw:I cleaned those hole edges while i was in there because I noticed that there was a piece of long thin burr left on one of the holes.

The rubber/plastic tip on one of the float valve cones looks like its getting some wear. doesnt look horrible though. barely noticeable.

I dont know. I'll throw it back together and change the oil again.
Will do a compression check next I guess

[Buffalony]

Got it all back together. 5 in the AM Did it clean though

I know the thread is about gas in oil. Im still on that and will update accordingly for those following.

As for the current situation. After getting it back together I started it and warmed it up. I noticed immeadiately that the idle was harder to adjust. I took it for a ride and it's a different bike. More predictable in turns and better pull through out. I will say that the idle was off and seems much more delicate to adjustment at the thumb screw. Before, when it was too high or too low, I would rev the motor and it would return quickly to idle. Now it is alot more sensitive to the correct adjustment. When the idle is low it will bog and when high it will hang. Does this sound normal?
After my ride I messed with the idle again and found what seemed like the right adjustment (It really is more sensitive now) When I got it adjusted to the correct Idle, I went out again. I noticed that my engine braking isnt as prominent as it was before I pulled the carbs. Then it was like me hitting the brakes. Now I have to use the brakes some more.

sheesh, I'd really like to take another local ninjette for a ride for reference

[kkim]

recheck your sync if you haven't done so, yet.