Cough of smoke on starting

[paulbaker1954]

Not using my 500 Four now the rainy/cold winter is with us but I do tend to start her once a week just to check all is good.

Always fires up on the button with choke out and a very light throttle opening - but I have noticed a cloud of oily smoke on starting up (particularly from Cyls 1 &2) which diminishes pretty quickly. It’s sort of an initial cough out of a bit of oil in the cylinders.
I am assuming this is down to a small drain of oil through the valves whilst standing  and is obviously slightly worse with the cold temperature (didn’t seem to happen in the summer).

My real question anyway -  is it worth pulling the head and regrinding all the valves again if this is something these bikes tend to do anyway when cold in the winter. I can live with a cough of smoke on startup in reality.

[RGP750]

No expert on this but some valves will always be open so regrinding the seats wouldn't sort it .
it will be valve guides or seals more likely.
Experts on here will know but i think the seals can be done with the engine in the frame.

[Bryanj]

Head and barrells will come off in frame, not worth doing till oil consumption is noticable

[Trigger]

There was a update on the seals, as the early ones did not have a ring clip. But as Bryan says not worth investigating.

[Johnwebley]

my own  500 smokes a little on tick over when hot,or on the sidestand,nothing on start up,so I am not bothered,

I had the head and valves out about 10k miles ago and replaced all the stem seals,but I guess they were not to good quality,

 as for starting it weekly during the winter,I personally would not,unless you can run the moter on a dyno to get it good and hot,you
will promote corrosion ,in the motor,and those very expensive exhaust pipes,
unless its stored in a damp enviroment,the motor should be ok,

[matthewmosse]

 You may find it inproves with a good long ride in any case. I had one engine that leaked from the crank seal like a bad un when I first got it, had to keep using it as it was my only wheels and after a week of regular use that leak was completely cleared up. It was either a cb500 or 550 motor, it might be significant that it was in winter that this happened. I would not worry unless it used a lot of oil over a period of use. Mine used nearly a pint in its first 80 odd miles and was looking dire, but completely stopped leaking over the next few hundered miles. Might indicate the rubber doesn't shrink with the metal when cold due to age, until softened by the heat of the engine or something along these lines.

[paulbaker1954]

Thanks for all the input

The engine was completely rebuilt last winter as part of the restoration including new valve oil seals new pistons and rings ... so maybe the aftermarket seals (they did have springs) are oozing a bit

I think I will not worry too much and just see how it all beds down, after all the engine has only done about 700 miles since the rebuild

Oil consumption is virtually zero anyway

[Ashdowner]

I had exactly the same leak as Mathewmosse. Cleared up after a couple of weeks use.