Exhaust Smoke coming out the inlet?
 

I started my engine up over the holidays to let it run for a few mins as it had been sitting for about 6 months. I noticed once it got going that around every 5-10 seconds I'm getting what looks like a puff of smoke coming out of the #3 inlet port. Any ideas what this is likely to be and how to fix it? I thought it could be a timing issue but wouldn't that mean it should be happening out of port #2 at the same time?

what engine have you got there ?

1.8 CVH with zx6r carbs

Do you still get it when the engine has reached temperature ?
Not saying it is likely to be the head gasket but for peice of mind it's always worth doing the basic checks if you are experiencing this- Leave it running for a while and check your water level before and after. Compression test all cylinders to ensure 2 and 3 are similar to 1 & 4.

I haven't got the coolant system completed yet so I can't let it run up to temp properly at the moment. It's had a new head gasket awhile back so I'm hoping that's not the problem... I'll have to get ahold of a compression testing gauge then and see what that shows. Thanks for the advice :)

fingers crossed. Heres hoping it's timing

Sounds like a worn valve not seating properly.

CVH has hydraulic lifters I believe, if its been sat it might just need to run for a while at full temp.

Did you have the head to bits when you did the head gasket, cos I do tend to agree with Phil that it does sound like poor seating valves


Arfon

Nope I only renewed the gaskets and gave it a good clean. If it is the valve causing the problem, will it need completely replaced or just adjusting the clearance sort it?

Take the head off and give it a quick clean, turn it upside down so it's head gasket side up and pour a little petrol in the combustion camber. If the valves or seats are worn the petrol will seep through to the inlet/out ports. If there is only minor pitting just use course then fine grinding paste and a valve stick. If you've taken the head off then I personally would replace the tappets and valve seals while I'm at it.

At this early stage and without cooling the only thing you can do is take off the rocker cover and rotate the engine by hand and see if the lifter is slow returning after being compressed.
A compression test will show if your valves arnt sealing
Hydraulic lifters are renowned for building pressure slowly after sitting for a long time

if the lifters were not full the valves would be less open.

it may just be a sticky valve.

TT

If the lifters are slow returning then valves would not close

They don't return.

They fill with oil and expand to fill the gap between the rocker and cam and move in the follower bore. Once full they stay full unless faulty.

TT

They have a spring in them and the fluid volume changes as the cam rotates

Why on earth would they do that, and how?

You need a constant distance between the cam and the rocker otherwise your valve timing and duration would be all over the place.

TT

I'd still say it needs running up to proper temperature for a while, and possibly and oil change if not done already.

Some reference material from a well known publisher, :D

http://www.angelfire.com/bug/joro/manualz/1737-02B.PDF

Got the official ford "Technicians Product Information and Training" here.

TT

I got Tis, it was just easier to find something online than find where I stored the ISO lol

It could be as simple as a lean burn misfire if its on bike carbs.It only has to be lean on one pot and it will spit back and pop on a pot. I would not touch the thing with the spanners untill you have run it up to temp with water in the system and checked all the obvious. All this random stuff is exactly that, of all the suggestions someone will be right just by chance.

bob

Not sure if this helps but I had an R6 a few years ago and had problems with it bogging down when pulling off, took it to a bike repair shop and they found it to be berthing back out the inlet, turned out to be worn piston rings. Might be worth considering. Joe

Thanks for all the replies on this one guys. Still haven't had a chance to do anything about it yet, mrs has been keeping me busy working on the house :( Hoping to get the coolant system sorted soon so I can try getting it up to temp and see if it still does it. The engine has more or less been sitting in the roadster now for a couple of years only being switched on briefly every couple of months.

It can't be that long can it?

TT

Ya it's amazing really how quick time goes by sometimes :eek: I'd love to finish the build off by the end of this year which would make 3 years but it's unlikely at the rate I'm going!

It does not matter how long it takes you to build it as long as you don't stop.