Quick Questions

Quick Questions

81 Seca550

1. Is it normal for oil or gas to be inside the airbox?

2. When reinstalling the carbs, what is the best way to get the damn thing back in safe and sound? Do you put the air box boots on the carbs first or do you just leave them inside the air box?

Thank you in advance!

 

1) No it isn't normal. If its gas in the airbox you probably have carb issues such as a stuck or incorrectly adjusted float. If its oil you may have too much oil in the crankcase or possibly blowby pressurizing the crankcase.


2) When I did mine, I left the boots in the airbox and was able to manoeuvre the air box and carbs to get them in. This requires loosening the screws which hold the box to the frame.

 

Depending on the amount, it could be no more then too much
oil in the motor.
Or, it could be fuel has entered the crank case and increased the total volume in the sump causing an overflow.
You can get lots of oil there if by chance (pls dont ask how I know
this lol) the side stand comes back up (bike running) with your chaps but you didn't notice it.

As for the carbs; I use armoral inside and out on the manifolds.

While your stuffing the carbs in have the rubber air boots soaking in
Very hot water. They will be real pliable and easy to put in.

 

A little oil say residue is normal sounds like you either have to much oil in the engine or your carbs filled up the crankcase with fuel, check your oil for gas smell you might want to change it. Heres how i install carbs, make sure the air box is all the way back and tighten up the bolts that hold it then i take and warm up the intake rubber with a hair dryer so they are good and soft install carbs then I warm up the air box boots and install into the air back box center first then the outside. Once all those are in I loosen the bolts holding the air box push it forward all the way and tighten the bolts and all the clamps.

 

There is normally a crankcase breather hose that pulls blow by gases from the left rear corner of the crankcase into the airbox for reburning. It's normal to get a bit of oil from this PCV. If it's more than a bit, there may be a problem with the oil separator that's behind the cover where the breather hose attaches to the crankcase.

 

Great Advice Guys! And there is only a bit of oil residue inside the box. Thanks again for the info!

 

Your airbox has a little "breather element" in the bottom drain, like cars used to have on the side of their air filters.

I ordered a new one from Yamaha and got a square of foam that in no way fit or resembled the original part.

So I went to the auto parts and bought a generic "breather element" ( the stuff that looks like white Scotchbrite) and cut out a circle to replace the gummed-up nasty original.

The airbox is an integral part of your crankcase breather system; check the little filter and make sure it's not gummed solid. Mine was.

 

bigfitz,

Do you mind taking a photo of this? I do notice that under my airbox there is a drain tube, but there nothing attached.

 

Bolted on the inside of the shifter plate are two metal compartments, and behind those compartments are two breather gaskets and an intricate series of grooves and channels. These are designed to seperate the water and air that are trapped in the oil from crankcase pressure. The oil is recovered and the air and water vapour are supposed to exit through the breather hose.

If XJ owners look behind the shifter plate they may find, like I did, that the ancient gaskets are hard and impermeable, and the chambers and channels are coated or plugged. So the engine has a very difficult time "breathing" ie relieving the pressure, and oil, water, air mixture can be forced into areas you don't normally see oil.

If, when you change the oil, you may notice white scum on the surface of the old oil. That's emulsified H2O. You should get on the (relatively) simple and cheap fix of cleaning the chambers and changing the breather gaskets.

 

NOT on the 550s. He has a 550. Those passages are part of the clutch cover on the other side of the bike, on the 550s.

NOT ALL XJs are exactly alike. Please be careful with model-specific advice; the 550/600 series are quite different from the "shafties."

sushiplease, I would be happy to get you a pic or two. I'm pretty sure my spare airbox has the little drain filter intact, so photographing it might actually be feasible.

Give me a day.