NC24 Smoking on Startup

[clubber122]

Hi guys

I've recently noticed my NC24 is smoking for a few seconds when i first start it after leaving it for a few days, i had the carbs off when i first bought it and rectified a few previous owner induced problems, and while i was at it i cleaned the carbs out and it ran sweet as a nut but has gradually gone back to a really rough idle fluctuating by 500RPM, im thinking the two problems could be linked, well im hoping they are, i thought maybe the carbs had sucked some crap in to the float plunger hole and it maybe isnt seating fully and letting a bit of fuel through as i can always smell petrol around the bike but cant see any leaking out, any input would be great

here is a video of the smoke it only does it for a few seconds then clears
http://youtu.be/w80mgPf7lzQ


Regards
Sean Holt

[Neosophist]

That just looks like condensation (i.e. water)

they all do it, especially after a few days as moisture collects in the pipes.. the NC24 especially due to the design of the collectorbox, mine smokes like a kettle till its warm.

As long as it stops when its warmed up its probably just water.

[clubber122]

That just looks like condensation (i.e. water)

they all do it, especially after a few days as moisture collects in the pipes.. the NC24 especially due to the design of the collectorbox, mine smokes like a kettle till its warm.

As long as it stops when its warmed up its probably just water.

yes, it does blow nice white smoke once its warmed up, this however was slightly tinted quite a bit ploom came out when i first fired it then i recorded it, its maybe slightly blue but only slightly

regards
Sean

[Neosophist]

That just looks like condensation (i.e. water)

they all do it, especially after a few days as moisture collects in the pipes.. the NC24 especially due to the design of the collectorbox, mine smokes like a kettle till its warm.

As long as it stops when its warmed up its probably just water.

yes, it does blow nice white smoke once its warmed up, this however was slightly tinted quite a bit ploom came out when i first fired it then i recorded it, its maybe slightly blue but only slightly

regards
Sean

Have you actually taken the bike for a good ride?

It needs to heat up well for the condensation to burn off. You will also get condensation burning off out the oil for a while too.

If it keeps doing it you might have a failed head gasket leaking water into the cylinder.

Check your oil for any signs of milkyness.

[clubber122]

oil isnt milky i checked the filler cap yesterday, its clear once ive been for a run!

[hunter]

This sounds like worn valve guide seals,
When you run the engine the oil pumps to the top end,
Then when left over night some of that oil finds it's way through the seals onto the valves,
Then burns off when started from cold.

[clubber122]

This sounds like worn valve guide seals,
When you run the engine the oil pumps to the top end,
Then when left over night some of that oil finds it's way through the seals onto the valves,
Then burns off when started from cold.

should they be like that?

[Neosophist]

This sounds like worn valve guide seals,
When you run the engine the oil pumps to the top end,
Then when left over night some of that oil finds it's way through the seals onto the valves,
Then burns off when started from cold.

i just posted the same thing in another thread, the picture above looks like it too

[clubber122]

This sounds like worn valve guide seals,
When you run the engine the oil pumps to the top end,
Then when left over night some of that oil finds it's way through the seals onto the valves,
Then burns off when started from cold.

i just posted the same thing in another thread, the picture above looks like it too

Whats the fix???

[Neosophist]

If its valve stem seals the only way to stop it leaking / burning oil / shitting up your valves is to replace the valve stem seals, there about 8 quid each and youll need 16 as well as new head-gaskets.

If you dont mind it burning a little bit of oil you can probably live with it for now, depending on how bad they are leaking.

Start by cleaning off the valves best you can, some high penetrating carb cleaner can be used but becareful of getting crap in the bores / washing away the oil.

If you dont know what your donig too well try and find somebody local who can give you a hand.

If time and money was no object then the ideal course of action would be to determine if it is the valve stem seals, get the head off, clean the valves off and replace the stem seals, clean and re-lap the valves into the head and re-assmebl.

Of course a lot of these bikes can cost lot more than they are worth to get tem in good running order again which is why so many are abandonded.

when riding the bike rev it up quight high then shut the thorottle off and let it slow right back down the with the throttle shut, then gas it again and have a look for smoke from the ehxuast, if the stem seals are really bad the pressure when you shut off the throttle will suck oil from the stem seals and itll burn off when you gas it.