Superfour Vtec Cold Starting Issues

[craigs23]

Hi,

I wondered whether anyone can shed some light.

My 2000 Superfour (first Vtec model) takes ages to start when cold (when it's not been used for 8 hours or so). It'll eventually fire into life, albeit only on 2/3 cylinders, before it warms up, and runs as it should.

There are no issues when starting the bike again once warm.

I've fitted a new battery, coils, plugs, HT leads, air filter, aux air filter and have had the carbs balanced. The carbs are clean, but I treated the fuel to some cleaner too just in case.

Still no joy.

Some suggestions I've had are valve clearances (the bike's only done about 15k though), carb rubbers or even the dreaded head gasket.

Am I missing anything else? (Hopefully less expensive - some workshops have been put off the valve clearances due to it being a Vtec).

The odd thing is, these problems seemed to start when I did an oil change over Christmas :/

[maranci]

Hi
I suggest you take a look at the breather pipe of the petrol tank. Is it breathing as it should? remove the tank, open the filler tap and inspect the holes. They could have dust or dirt trapped inside. Try blowing with compressed air. Also did you check the proper type of spark plugs ? Regards

[dobbslc]

Hi I would also suggest checking the valves, maybe doing a cold compression test on it may show something more easily than doing the valves first.
Check the plugs or replace them if they are looking sooty, a couple of failed starts on these things can bugger them.
Test the ignition pick up resistances and check wiring / plugs for damage,
When did it start playing up? Before or after the carbs were worked on?

[craigs23]

Many thanks for the pointers.

I think the problem's attributed to the breather pipes, as the bike seems to start as it should when the fuel tank cap's open. However, I cleaned out the pipes as best I could, but the bike still has difficulty starting with the cap closed :/

At least I'm getting closer to a solution, thanks again for the help.