Ive got a bit of a misfire...

[burnard]

Hi guys,

Im having a little trouble with my engine, Ive got a video which shows the issue quite well. Was hoping someone may be able to help?
Basically the engine is an E16SE, on bike carbs with a ported head.
Im getting a fairly consistent misfire around the 4500/5000rpm mark.


http://www.youtube.com/watch?v=KwUY43orw4w

Feel free to laugh at me spinning out.
The car that over took me is running a C20XE.


Thanks,

Chris.

[dgbnova#1]

Great video sounds awsome and no one will even notice the spin lol
what's it running ignition wise as could be many things causing this mis fire and what have you done so far to rectify it

[burnard]

Its running a distributor kit from H&H ignition solutions.
Omex clubman rev limiter.

Have tried fueling, unplugging the limiter and the tacho, but still not found the issue.
Its had new plugs, new leads, new dizzy cap, new rotor arm aswell.

thanks,

Chris

[novalew]

What filter are you using on the carbs? Ive read that socks can cause problems

[tom reid]

You could check, fuel pressure, ign timing, pump location, plug gaps, plug leads, coil, air/fuel ratio.

[burnard]

Hi,

Done that tom, its had a brand new pump, with an 8mm fuel line fitted, as said, its had new leads, and ive played around loads with the fueling and it always does the same thing.

It is running a pipercross foam filter:
https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-frc1/t31/333758_10150685186915853_1995503290_o.jpg


thanks,

Chris

[meritlover]

You say you've played with the fuelling. What is the AFR doing just before it misses?

[burnard]

There is no AFR gauge on this engine, so i cant tell.
i am however, sure that it is not a fueling related issue, ive spent the best part of 2 weekends adjusting the mixture, and there is no change to the missfire.

[tom reid]

What size jets you tried?
What fuel pressure are you running?
Where is the ign timing at?
Is there a squeek, might indicate an air leak

[burnard]

tried 1.5, 1.6, 1.7, 1.8 and 2.0 mm jets.
0.8, 1.0 and 1.5mm idle air jets aswell.

Fuel pressure was arround 3psi from the origional bike pump, swapped to a facet 5psi pump.
They are zx6R mikuni carbs. 38mm ID.

ignition timing has been set at 10 and 15 deg, still no change.

No squeeks.


What are the plug gaps meant to be set at?

[tom reid]

Depending on ign system around 0.8-1mm

[burnard]

I got a chance to check tonight, and the plug gaps are correct.