Gas smell in oil

https://youtube.com/shorts/T3HphE3BFBo?feature=share

 

Well I guess that wasn't the problem. Checked the oil level, and it's more than full and I know I left a little space in the window to check. Draining the gas from the tank and try to figure this out again.

 

Do the needle valve seats have copper washers? Do these need to be replaced or the old ones annealed and could this be causing the fuel to get into the crankcase? I am no carburettor expert lol but l wonder if this can be a cause. No this won't be it just read back, you got parts from Len.

 

Brand new ones from Len, so that's not the issue I'm sure. I only use his parts now!
I just took the carbs off, and #2 exhaust boot was full of gas. All the intake boots have a little gas on the inside of them.

 

Is there anything on number 2 that looks different to the other three carburettors with the float bowls off. Are the needle clips fitted property. Not nit picking your work just trying to figure out what is the cause of this.

 

the only way that can happen is if the petcock isn't doing it's job
if you take the valve seat out, your back to float levels again

 

I just changed the petcock with parts from Len, unless I put it back together wrong. I'll take it off and take pictures.

 

@Glen F. at this point Im affraid you may have washed too much fuel into cam/crank bearings, I would drain all oil(and filter) refill oil and crank engine over without carbs or petcockvacume hose to ensure longevity of the bottom end.

Fuel thins the oil, and enables the crank and bearings to galge into each other causing striations and minute soft bearing fragments, that in turn galges even more resulting in bearing failure. and ultimately to a snapped rod/engine failure.

I only say this as your entire thread and testing has repeatedly dumped fuel into case. And just draining it does not replace the thined oil already in the oil passages of the crank/cam.
the vent tube and petcock is only for hard accelleration ensuring the carb bowls do not run dry/low.
for all your testing with your carb issues at idle and not in gear testing you do not need them.
a worn out petcock diaphram will either allow full flow, or hardly none at all without the vacume pulses to operate it. this is why 90% of people use a seperate fuel tank supply as to bypass this. again its not needed for light sharp accelerations/and idle/syncing testing.

 

It's a newly rebuilt petcock.
I will be changing the oil again, and turning the engine over without the carbs in as you say. I'll probably drain again and change after that. Changing the oil goes without saying.
Getting to be a pro at taking these carbs off and oil changes. LOL
I did put about 50 km last night, and when I got back there was no change to the oil level. Whatever happened, happened over night.

 

yes more you cycle and drain the safer you will be..

 

Will I have to fill it right up, or will half full do?

 

half will do if you "hand " rotate it, but if your starting it, it should be atleast 75% full.
once or twice should do the job as long as its new oil your cycling thorough.

Aditional info:
fuel in engines that share oil with a wet clutch, the gas can break down the clutch plate material and or make it soft, when operated in that condition will just shear the material right off the plate and mix into oil flowing around entire engine.

 

Now to figure out how to stop this from happening again.

 

its either your carbs, causing it, a leaking petcock pump, or terrible piston ring gaps.

take your pick, but if it ran strong before, Id suspect the first two.

 

are you 100% sure the float needles are seating (Air) tight?

 

Glad you don't think it's the rings! The bike has sat since the end of 94. When I rebuilt the petcock, I followed the video instructions from xj forever on you tube. I did everything as instructed. Carbs held fuel overnight before with no leaks.

 

How would I check that? I did leave fuel running to the carbs overnight with no leaks before I reinstalled them.

 

I think I already mentioned this little test. but here goes.

when you have the carbs off the bike and bowls off.... put a clean hose on the fuel "t" in between #2 and #3.
with carb rack drained, clean of fuel, and upside down (Floats on top side) blow into the clean hose you put on the T, then lift each carbs float up, you should hear the air escape.

Then drop it and let it fall under its own weight and the pressure in your mouth build up again if its not leaking, if it is leaking feel around the seat/needle for the air. do this for all 4 carbs. the weight, seat opening and close pivot point of the float is too heavy for the amount of pressure your mouth can produce. after flipping each float a few times, and as long as the parts are good no air will escape.

The mouth pressure you feel is the first indication that, that needle is seating securly. the wisping air sound is the tell tell your "not" seating securly. if correctly seating with all 4 floats own weight, you should be able to hold some pressure in your mouth. I do this for all carbs I rebuild weather a single carb, or 4. on cars, truck, bikes etc...

 

Great idea. Never heard of that one.

 

@Franz, My father was the lead rebuilder at a carb only rebuild shop here in Indianapolis for 40yrs
(Carburetor Exchange). As a kid in the summers I would work in there with him and see a 30ft long bench with carbs layed out end to end, all with new/cleaned parts ready for assembly. each day that was his job, and periodocally the service shop would call him over across the parking lot to help them adjust them out. Local hot rodders would come by the house and buy specialty builds from him. it was basically free education for me... well until fuel injection took over lol.

on my mothers side, my aunts husband worked there with him for 15yrs as well, then opened his own shop.
his son, my cousin, runs a pro shop out of the same building now. so engines,mechanicals, and especially carbs was just in my DNA from birth.


Im sure @hogfiddles in his shop and years has his own little secrets and tricks for his craft as well.

 

I tried the blow test. When I lifted the floats one at a time, I could hear air. Drop the floats one by one and nothing but pressure. There was still a bit of gas left behind, so I can hear the hissing of air. I did that 4 or 5 times for each. Len's parts are working.

 

exellent... so now you can confirm the needles are in fact sealing. heres why I mentioned the needles

fuel from petcock will stop flow at the needle valve weather you leave the valve open all night or not, the difference is a bad petcock valve can bypass the needle and seats, by flowing to the vacume tube used off #2 carb intake boot. its like an open door for fuel if the petcock diaphram is bad. but now you know which is likely your issue

 

I'll take the petcock off again and do some more polishing. I did get a new rebuild kit.

 

I don't think I can get that little bore any shinier

 

thats the pump diaphram side, you want to polish out the valve side as well...assemble valve side with a "slight film" of lube on the 4 hole seal. all over it... slight amount will disolve in a tank or two running thorough it, and should not pose a long term effect on deteriating the rubber.

 

That is where the gasket that has a metal piece on it fits in there.

 

yes, the seal is round with 3 holes. the metal is the lever, and on its mating surface will have a half moon slot in it. when you rotate the valve fuel flows from one hole thorough this half moon groove, and into the outlet hole in the seal. the 3rd hole is the reserve hole. if you dont "clock" the seal in the petcock befor you assemble it, it has ability to not shut off, or not turn on.

show me your metal your talking about?

 

That’s not necessarily excess gas. That’s a HUGE indicator of VACUUM LEAK..... not excessive gas, excessive AIR

 

@hogfiddles is correct, vacume leak, or sticking slides...

 

@hogfiddles, Im curious as to your service for rack builds.. do you place them on any bike to do any adjusting, or just set them to all their so called respective defaults?

 

I did the propane test with no increase of rpms

 

ok, yes a spring is in there as well, the metal on the diaphram is just to keep the spring from rupturing it, resulting in longer life for the seal.

then you have an internal possible cracked base, or the slides are still sticking...
answer this for me... when you look into the carbs, how much light can you see past the fly's (throttle plates)

 

I have benched synced before putting them on the bike. let the bike warm up and sync then color tune then sync again. I don't own any other bikes.

 

I didn't show the spring, but it's there.

 

I used a paper clip in the middle of the bottom of #2,and adjusted 1 then 3 and4 with another paper clip the same diameter.

 

Sorry I meant for your customers rack jobs.. but I see your answer, about not having all bikes.. therefore it would be impossible to do this for all racks you do.. thanks, was just curious.

Edit: this was a question meant for @hogfiddles

 

My dad was the mechanic, not me. 58 years young and still learning.

 

I always start out with a piece of papers thickness, and adjust up as needed to start, then start adjusting the 'Air mixture" screws.

 

I set them to initial settings. It is the responsibility of the owner to dual them in for their bike.
I do not do the wet setting, either… That is something that the owner should learn how to do… Plus, many times a rack and sent back and it stays in the bag for a fairly lengthy period of time before a Bikes is ready to run again. I am not going to introduce gasoline into a carburetor rack, and then have it sit on A shelf for a long period of time and end up with dried gas residue inside. That totally defeats the purpose of having Them thoroughly cleaned and rebuilt.

 

I had thought about using old credit cards, but the instructions from this site said to use a paper clip, so I did.
Where else could I look for a vacuum leak?

 

papers thickness is a visual of amount of light seen when holding rack up to lights. I dint put paper or anything in there. its all visual..

 

You can’t adjust 3 ( other than with the idle speed screw). 3 is the “guide”. Basically you set 3, then set 4, 2, and 1 to match. There’s a big of finess to that, but it takes me about 2 minutes to set the bench sync. The fastest I ever did it was 53 seconds. Bench syncing in NOT hard. I don’t use card stock, or paper clips. I use my eyes.

this is ONLY for bench syncing, so the bike will be in a condition to start and run so you can get it warmed up to do a running sync. RUNNING sync is when you will dial in the carbs.

 

So I should tighten them up just a bit since you are saying the light should be about paper thickness?

 

Ya but you deal with these all the time, and many more than I can imagine. All good, I'll reduce the light passage.

 

you said your propane test passed, so it would almost have to be internal in carb...

 

Thats a starting point, which is likely closed off too much, but this is my method. I would rather start out too little open, and gradually increase it as needed, than to start with too much gap and have to adjust it lower while keeping track of its position while adjusting air mixture screws and mental noting thier positions as well.

 

cylinder 1 fires first, so I (personally) set all 4 on a bench sync to a low papers thickness of visual light on throttle plates, install on bike, start and adjust 3 as needed to get to run, then I adjust cyl 1 first, then 4 and then 2. manupilating lower idle as necessary to keep rpm in range.

(PDF) specs manual says 1200rpm factory, but I run the idle of my fathers 550 at 1100 rpm idle.

 

I'm not sure where to go then. I replaced the throttle shaft seals with o rings that were recommended here. Maybe I should order new seals from Len.