Smoking jota

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GT

GT

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Hi, I have posted on this topic before, when my series 2 180 was missing and fouling plugs etc. Now i have sorted carburation and she starts and runs fine, idles fine etc. however, it still smokes after idling - lots, clears pretty much as you pull away. The longer you idle, the more white smoke she kicks out, then after a few hundred yards it disappears (to the eye anyway). Oil consumption is 550 miles to the pint. Engine sounds ok, no bad sounds. I have tightened exhaust manifolds.

I can see from history file that it had only travelled 500 miles from 2003 to 2011, but at 35,350 miles ( in 1998 - it is now at 39,500) it had a top end overhaul, rings, valves, guides. A note on the invoice says that Inlet valve axis are not true to seats, new guides did not solve the problem, but that the bike ran ok. Might this be a clue?

I think the next step is to drop oil into the bores to see if it points me to rings or guides. How much oil should i drop in and how do I clear it out after test?

Any ideas.

Regards
Glenn
 
The smoke at tickover sounds like valve guides, bit bewildered by the note on your invoice, reads like bulshit to me. If the guide bore is not concentric with the seat the valve will not seal.
  Would try a leakdown test rather than dropping oil down the bores, at 550 miles to a pint of oil I would suggest some engine work is not too far over the horizion.


  Keith.
 
note on the invoice is bullshit, love to know who did your head work
let me get this right, they changed the guides but then never cut the seats true to the guide axis ?
sounds like a fine head job indeed  :o

I'm with Keith on this one, you need to do a leak down test and find out what you really have


Good luck
Red
 
I have similar smoke symptoms

I took the compression with a spoon of oil into the cylinders. For me the problem was the head gasket

Everything is rectified, and all joints of the engine top changed, but the bike still smokes.

I think these are my segments that are glued (glued ?  is it the good word ?)

Xavier
 
Glenn,

Agree with Keith and Red, comment on guides not being true to the seats is utter bullshit!  If that is really so, the leakdown test will only reveal leaky valves.  Hopefully they do seal decently and you find a fault someplace else.

Oil consumption may stem from worn guides or pistons/bores/rings.  Fitting new rings in a worn bore on old pistons can only be considered a stop-gap measure at best, especially at the stated mileage.  Stock triple pistons are usually well past their best by 60K-65K km, approx 35-40k miles.  The top ring groove is by then worn to the extent where the piston and top ring effectively work as an oil pump...

With a head job done like that, the remainder won't be much better, expect the worst... :o

piet
 
VanguardontheLav said:
Being ignorant, I always understood that oil smoke would be blue... And smell of oil/burnt oil...

What have I missed? Does oil now burn white?

--
Dick
Click to expand...

Traditionally, you might have been taught oil smoke was blue and white smoke (steam) is white, but oil smoke can also be white when burnt and its obvious because it stinks. Probably temperature, type of oil and the amount its burnt that makes the difference. Whether its come down the inlet valve and passed through the combution chamber or just passed into the exhaust port will make a difference too.

Smoke upon opening the throttle after idling is almost certainly running down through the valve guides but as always its wrong to make assumptions and the right diagnosis has been well documented above.

Rob
 
My bitza used to smoke when hot after a few seconds of idling. Cleared up straight away when I pulled away.

The smoke was a gray/white. Once I put the DMC2 on it, it stopped! It did it with both the original ignition and a Todd/Boyer setup I ran too.

Not sure why - perhaps the mixture was very rich just to get it to idle with the older ignitions?
 
If the fuel mixture is over rich...The bores may be being washed off with fuel ..Dis can cause de cilinder to glaze.and da compression to be very low..It will also cause da oil to be burned up alot. Check da plugs for da sooty stuff...set the mixture correctly...If still smoking have the cylinders glaze busted.

I had this issue on my boxer...I knew I had good bores...but one side smoking like a Pitts aerobatic aeroplane. After much hassle with a gallon of oil burned over a 1200 mile trip to Ireland.I did a compression check and found left cylinder something like 25% down on right..sooo.I took the bike to Cylinder rebores in Nuneaton..and I explained the problem to the engineer there while I started the bike up for him to see the smoke..There I was hypothesizing about valve guides and rings and all sorts of technical stuff ..when the engineer said...I can smell petrol..shes running rich. So I asked will that cause her to burn oil tho ?..Oh yes it will he said..and I said but will it cause a compression drop tho..Oh yes it will he said..further more it will cause your cylinders to glaze over. Go home and check your mixture settings..

I went home and found idle mixture on the offending cylinder was a whole turn out on the rich side...Hmm I set back to factory basic setting.

The smoking stopped completely ..immediately.

lesson learned

joe
 
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