White smoke from xj650

So I've been messing with the carbs recently and I've noticed white smoke starting to come out of the exhausts.

This persists even when at operating temperature. Is this the start of the head gasket going or could it be something such as piston rings or valve guides?

Xj650 maxim

 

If your head gasket was the cause a compression test with the throttle held fully open should confirm it assuming the rings and bores are okay which I think they will be. As the white smoke was not there before you worked on the carburettors perhaps the mixture screws are set wrongly, it won't be the rings or valve guides if the problem was not there before. What is the oil level in your engine, have you changed it? It you have too much it can get past the rings into the combustion chamber that would cause white smoke too I think.

 

I wouldn't have thought the carbs would be the cause as white smoke suggests oil and gasoline is black smoke.

I havnt got a compression tester to check that and I dont fancy paying for one for the sake of it.

Yes I changed the oil several weeks ago to the measurements that are on the side of the bike.

 

White smoke is never caused by oil.

Pull the spark plugs. I'd bet that you're running rich.

 

This is the spark plug

 

Yes plug is black and sooty K-moe is right it is running rich.

 

The first pic is the furthest left spark and this is furthest right. Left plug is dry and right plug is wet

 

Very rich.
What jets are in the carbs, and what are the idle mixture screws set at?

The wet one is wet from gasoline, correct?

 

The ones that probably left the factory. I've only had the bike several weeks so I havnt done much other than clean it up and get it to run.

Idle mixture screws are probably at 3 or more turns out. I'm going to bottom them out and start again

Yes it is gasoline

 

So I'm 2.5 turns out, idle screw isn't touching the carb and its sat at 3k revs... stumped!

 

I've just uploaded a quick video to YouTube to show the smoke... I'm now at 3 or 3.25 turns, no idle screw but its idling at 1.5k revs

 

That just looks like condensation from the bike not running long or running when its cool out. Get that bike up to proper running temps and it will most likely disappear.

It would have a very distinct smell if it had gas or oil in it.

 

Do you think? When you say it has a distinct smell, is there anything in particular I should know? I've never smelt burning oil before believe it or not!

 

That's water vapor. Place your hand over the exhaust plume and let it soak your hand for 10 seconds. If you get dry or oily soot on your hand then you have a fuel or oil issue. If just gets damp and just smells like exhaust then it's water vapor.

 

Might want to drain all of the bowls and make sure you don't have water sitting in the tank and bowls that's getting sipped up.

 

Looks like water vapour to me too guys. By the way Maximus I used to work in Keighley I liked the road from the motorway to Skipton was good on the XJ. About 40 miles it was.

 

Thanks all. I did recently clean the tank with acid cleaner and thought I got all of the water out. I also filled the tank after to brim and put some engine cleaner in with it.

Ah nice! I'm from Silsden so I know the area well. With a 40 mile commute I imagine you're not local?

 

No 200 miles I am near Glasgow it was 160 miles from Glasgow approximately then 40 to Keighley I meant.

 

And your xj happily went along for all those miles? At the rate I'm going with mine I'm losing faith and not willing to spend much more!
I bought it as a none runner, got it running and cleaned the carbs - to the best of my ability without breaking the rack.

Bench tuned the carbs and tried to tune them into the bike and this is where I'm at.

I've done other stuff like replace and sharpen up the rear brake and I've got a section of pipe on order to replace the front brake but other than that I'm stuck with the white smoke/water vapour

 

That's where the white smoke is coming from.

 

I made the journey once a month. Check all you can without spending any more money.

 

I wouldn't have thought engine cleaner would cause the white smoke

 

Yup.

IMHO "engine cleaner" and "injector cleaner" fuel additives, as a general product, are about as effective as sprinkling borax on a fire ant hill. If you want to remove carbon from the piston and valves to any extent they need to be soaked and agitated. CRC Direct Injection intake cleaner does a great job at dissolving carbon from DI build-up but it takes a while and the carbon soup left is nasty to clean up. But I digress...

 

I'll let the tank run empty and fill up again to see if the smoke stops. If it does then your theory is correct.

I actually used more than I should have, the bottle did 50-60 litres and i probably used 3/4 of this - not intentionally. It just came out way quicker than I expected and didn't have a measuring gauge on the bottle

 

The cleaners work fine as a preventative, but then most gasoline already has that stuff in it.

A stalling-dose of Seafoam will clear carbon out, but it won't clear out everything.
I use it as a pre/post winter fuel additive to help keep the carbs clean, and to remove sludge from an engine that has sat for a long time.

 

That is definitely where the smoke is coming from.

The "stalling-dose" of Seafoam I mentioned above...well the result of that is turning the exhaust gasses onto a naptha-powered fog machine (as in coal-burning London fog). You're buring it at a higher concentration than would be normal, hence the white smoke.

 

We don't get that over here. But nevertheless I'm curious about what OP calls 'engine cleaner' WTF is that? Redex or some other snake oil? If you want to treat your engine, give it an extra oil change.

 

I don't like Redex I always change my oil when recommended don't know about the other engine treatments but regular oil changes must be one of the most important ways of keeping an engine in good condition.

 

did you use seafoam? it makes white smoke

I see you do not have that .

 

I’m guessing the 3k is sucking air somewhere

 

Redex is basically the same as Seafoam.
Naptha (of various types), a few other solvents in small quantity, and stuff to make it smell nice ( I like how Seafoam smells. ).

 

It is good for removing the sludge that accumulates when prior owners don't do regular oil changes.

 

Yes l recently replaced the PCV valve pipe on my car which l have had for a long time and the PCV valve was in good condition because l changed the oil regularly.

 

Think I found the source of the vacuum leak...

 

Well, that's one anyway.
A tear in the slide won't affect idle speed. It will make it harder (or entirely prevent) for the slide to rise, causing improper fueling above 2,000 RPM.
That tear is right on the edge where the seal is made. Might not be leaking much at all.
I'd patch it up with RTV and use it. Don't seal it to the carb body or hat.

Why you should replace butterfly (throttle shaft) seals.

^that^ is one of the most common sources of a hanging idle.

 

I have a back up set of carbs so I "borrowed" one of the diaphragms from that set. I find it near enough impossible to locate new seals in the UK for a US import bike.

I'll reattach to bike (bench tune first) and see what happens. If it still hangs then that will be my next call.

I've done the starter fluid spray test on the boots and theres no vacuum leak there

 

SAE #11 Buna-N orings can be substituted for the throttle shaft seals.You will need 2 o-rings in each location, and you will need to move the throttle some to "bed-in" the o-rings so the throttle plates close snappily.

The carbs are the same as were used worldwide, so throttle shaft seals from any normally-aspirated, aircooled XJ650 or XJ750 are correct.

 

Will any of these work?

 

If I'm not mistaken the 550 and 650 carb shafts are 8mm and the carb recess is 12mm. Most of the seals I've seen are 12 x 8 x 2.

 

Sorry I couldn't answer before I'd left the bottle in the garage and couldn't remember what it was (see pic)

Since I've had in the space of about 3 weeks I've given it 3 oil changes

 

there's your problem you want gasoline injector cleaner not petrol injector cleaner

unless you let your pet troll near your bike

I use one of these to keep the trolls off of my bike




https://answers.yahoo.com/question/index?qid=1006050320523

 

In my opinion that's a waste in a carb engine like this. There's not enough flow or pressure for it to work properly. You'd be better off pouring in a little cheap grain alcohol in the tank and drink the rest.

 

Haha... but gasoline IS petrol

 

But would it cause the white smoke or steam I can see?

 

To some extent it would since ethanol pulls water into solution. 100% ethanol can kill you if you drink it so the max you'll find at the pub is 95% where the distillery mixed it with distilled water. You can always distill your own 100% (within lawful guidelines) for cleaning, though. Steam in the combustion chamber during cleaning is good. It softens the carbon, on piston and valves, over the time it's running at operating temp. Just have to be careful with the weak spark on the XJ bikes.

 

The A011 listed on the chart is a SAE #11 o-ring
You will use two of them for every one throttle shaft seal that you replace.

 

According to the spec sheet that stuff in mainly paraffin (kerosene in US) with a hint of napthalene (moth balls) - not sure I'd want to go tipping that in my tank

 

You'll make me panic! Is it recommended I drain the tank then and refill?

 

Naptha is pretty typical for fuel treatments. Kerosene is also used in both oil and fuel treatments. Nothing unusual there.

 

I wouldn't panic, the quantities in those bottles are small. But, as has been indicated, since you are no longer burning just petrol you will get side effects (white smoke).
you may get 'some' cleaning benefit on teh top end but really I can think of better ways to spend my hard-earned.