Gas smell in oil

Hey everyone. Back at it again. Been having a hard time starting the bike. It would backfire when I let off the starter switch. Figured I would pick up a new battery, because I read it might not be strong enough to fire the bike, and try again. I can smell gas in the oil, and I'm sure this is not good. Draining the oil as we speak. I was using an auxiliary gas tank because I have petcock issues. I had an old lawnmower tank hanging, and filling straight to the carbs. Any idea why I would have gas in the oil?

 

The float needle and seat are not sealing properly...letting fuel escape out of the bowl and making it's way through the engine and into the oil sump. Backfiring probably related is my guess.

 

I kinda figured it would be the needles. I soaked everything in carb cleaner, including the needles. Lesson learned.

 

Sometimes a few taps with a screwdriver will seal them. I've read lapping compound does them good as well...or are they rubber tipped? What kind of bike? Model?

 

They are rubber tipped. 1982 650 Maxim

 

Yup lesson learned...carb cleaner eats rubber.
5N9?..with YICS

 

It is a YICS engine. Not sure what 5N9 is though.

 

Taking off the clutch cover as well. Might as well do the whole thing?

 

The question was out of curiosity. 5N9 is a model code.

It's on the neck as part of the VIN.
If it's a short VIN (9 digits) it will be the first 3 digits...5N9010101
If it's the long VIN (17 digits) it will be digits 4-6...JYA5N9003etc

It's also on the engine...first 3 digits. I think they are always 9 digits. Should match the frame unless the engine is not original.

If it were me I wouldn't bother...unless it's leaking.

 

1982-83 XJ650 Maxim Canada: 5N9

 

Yup 5N9.

Excuse the wood chips there, from when I was putting the carbs back in.

 

Is there anything else I should be looking for?

 

Might be a stupid question, but should I change the oil filter?

 

I would, for piece of mind.

 

Carb cleaner eats rubber? Maybe, but it shouldn't because it's petroleum based. Aand the float valve tips are not rubber, they're Viton I believe. Does it eat viton?
Someone correct me if I'm wrong please.

 

Viton is a trade name (Dupont, I think)...it is a synthetic rubber. I don't know if the float needles in the XJ's are "Viton" but surely they are a synthetic rubber of some sort. http://www.xj4ever.com/catalog/c-hitachi.html

Just because it is petroleum based that doesn't mean it's safe for all chemicals...
Viton has poor resistance to acetone, esters, amines, organic acids, acetic acid, MEK, ethyl acetate, highly polar chemicals, etc. https://www.calpaclab.com/viton-chemical-compatibility-chart/

Since many carb cleaners are proprietary it's almost impossible to know what chemicals and what proportions are "in the soup".

Personally I've found that soaking rubber (synthetic or otherwise) in carb cleaner has yielded poor results.

 

Yes, I was thinking about this whilst watering the greenhouse, my use of carb cleaner is in spray can form, and it is petroleum based. The soak and wait stuff could be anything I guess.

 

I'm still going to change them, because the rubber feels a little stiff, so they might not be sealing that well.

 

If in good shape, stiff is good. That is why solid metal needles work. They should only not seal is they are worn or misshaped. Normally worn would look like a ring or groove where the tip mates. Replacing should remove all doubt though.

 

So I took the clutch cover off, cleaned whatever there was there for gas in the cover, reassembled. Everything went well, but when I pull the clutch lever, it has almost no tension. What did I do wrong, or is there something I am missing?

 

Did you index/preload the clutch lever on the rod in the cover?
Did you unhook the cable in the lever?
Did you back the adjuster off and not re-adjust it?

 

I didn't index/preload the clutch lever on the rod in the cover, because I didn't know I had to. How do I preload the clutch lever?
I did unhook at the clutch cover and it went back ok.
I did back the adjuster off but did re-adjust it.

 

https://xjbikes.com/forums/threads/clutch-adjustment-clutch-cable-replacement-procedure.2672/

 

That makes perfect sense. Lesson learned.

 

That worked!!

 

Had the bike running for a little bit last night, but it went through alot of gas. Checked the oil sight, and it is way full. Pulling the carbs one more time to check the float height once again. I'll post pictures later. Just hoping it's not the rings. Might be more than I can handle.

 

check the needle valves probally leaking and need to be replaced

 

Just replaced the needles. I'm running an auxiliary gas tank until I get my petcock parts. Just wondering if that might be part of the problem. Posting pictures soon.

 

You replaced the needles and seats?...what are the lines coming from the intake joints?

 

The lines are for a cheap vacuum set up. I replaced the needles, not the seats. Just checked the fuel levels, and they are way high. I think I found my problem.

 

Do you wet set them?...good time to confirm they are closing like they should.

 

I did wet set them after I set them with a caliper. Not sure what happened, because they were all just at the proper level. Now they are way out.

 

Have a look at your gaskets...could they be catching on the floats and bending the tangs?

 

I'll check tomorrow. Going on 2 hours sleep, if that.

 

And if all you did was replace the needles and not the whole valve assembly with matching needles, I’d bet there’s more of the problem.

dfox

 

I had a Eureka moment at 3:00 am. As hogfiddles pointed out, I just changed the needles. The hanger is probably at a different height from the original needles, causing the problem this time. I can only hope that will be all.

 

Do I need to change the seats as well, or will changing the float height be good?

 

Luckily the shop took the needles back and ordered me both the needle and seat. Turns out the new needles, when I measured, were the same size on the flat sides, but were just a bit bigger when I measured on the cross. 4.17 old, 4.26 new. Oil is drained again. And now I wait.

 

Thanks Len for the new petcock rebuild kit and the bowl screws. You're the best! One less thing to worry about!

 

Dry set all carbs. All at 17.5. One floods the carb, and the others are fine. Measured again and all at 17.5. Why is one flooding?

 

could just need a few smacks with a screwdriver handle
could be a nick on the float tang that catches the needle as it slides up and down
might need a q-tip or golf tee with some toothpaste or polishing compound spun around a few dozen times in the seat to shine it up and smooth out any roughness in there
sometimes when you start it the vibration takes care of it

 

Brand new needles and seats. I'll check the float tang tomorrow.

 

Something is still hanging up

 

I changed the seat from one that wasn't flooding to the one that is, and no change. Tomorrow is another day.

 

Took some 1000 wet dry to the tang and the float rod and that seemed to work. I'll put them back in tomorrow and see what happens. Hopefully it will be good.

 

Had the bike running. Tried to sync, but didn't seem to work. Checked the plugs and 1, 3, and 4 are wet, 2 is dry. Put the color tune on and 2 is blue and the other three stay the same no matter which way I turn the screw. Looks like I'm taking the carbs out one more time.

 

Had this on one carb one time—-/ check the bore where the Main jet is—check it super carefully.... I had one that had a crack that could not be seen when the jet was out. Had to replace that body