running rough

[RedexRobB]

It is possible to buy dodgy plugs, even if they are new. Was it running fine before you changed them? If you have one particular plug that getting sooty, swap it with another plug and see if the same plug soots up. If it does then your problem is the plug/coil. If not and the one you replaced it with is getting sooty instead, then its probably something you have done wrong when reassembling the carbs.

I had a similar problem with mine where it ran perfectly, but sit the engine at 5Krpm and it misfired. Checked the plugs and no 3 was black and sooty, new set of plugs sorted it.

[lewisdale]

yer i was also gunna say might be worth checking the coils, ive got a set here if u need them

[eddy]

using cr9ek plugs and no there fine but its definately fuel related im sure of it and my mates got a 400 and nicked his coils and leads and no better and it was no different with two different sets of plugs but ive had the carbs apart three times now and they are gleaming thats why im a bit lost

[lewisdale]

well if the carbs are all built properly and there are no air leaks theres not much left in the fuel system to be wrong, did you set the float heights right? did you replace the o rings around the float needle housing?

[eddy]

didnt touch the float levels i might give that a try and see what happens

[lewisdale]

try that, otherwise its gotta be electrical

[eddy]

but wer do you measure from

[lewisdale]

from the surface that the float bowl bolts down onto, then you tilt the carbs slightly untill the float is just slightly resting on the needle and then measure

[MillaMeter]

Hi,

I have the exact same problem, anything under 4k and you might aswell get off and push it. I've done exactly what you've done. Sealed the inlet manifold holders, new spark plugs TWICE! new coils (5 different coils!), new leads, carbs cleaned and checked a million times. I've even tried another set of carbs, exactly the same problem. Every time I check the plugs, cylinder 1 is black as arseholes and 3 is on its way to the same colour. I've played with the float heights and still no luck. I've tried 14mm and it runs perfect below 4000 soon as i get to the top end it's skunk. I've even tried all standerd parts and jets. I give up. Just saving me pennies now for a Dyno now.

Regards

Rich

[eddy]

tried float levels they where slightly out but not far and didnt make much difference but think i know what it is now i had to bodge my exhaust ie weld new straight bits in and attempt to straighten other bits but welded a new bit in on number two pipe and it had a tiny pinhole in so small couldnt even here it blowing so sealed that up but noticed the pipe is still a bit bent but after sealing that it runs a hell of a lot better so going to try a new set of headers and see if that works

[eddy]

problem solved new set of headers and now runs mint but only thing is its feels a bit flat just after 4k now anyone got any suggestions on how to solve this one

[RedexRobB]

problem solved new set of headers and now runs mint but only thing is its feels a bit flat just after 4k now anyone got any suggestions on how to solve this one

What headers did you buy? More then likely different to standard which will cause a difference in running overall, usually best sorted on a dyno

[eddy]

delvi somethin or other stainless ones but dont know any where round here to get dyno and plus cant afoord it would it not be an idea to maybe go one size up on the mains oh and its also got a scorpion can if that makes any difference

[RedexRobB]

Delkevic? I think they are supposed to be a copy of standard pipes, so the flat spot at 4k could just be how it would normally run, Im not sure how it should ive got a beet system on mine, but not sure what difference the end can makes. Always worth a try going up a size on the mains as they are cheap, but itll never be perfect unless you get it on a dyno.

[eddy]

im sure its running a bit lean it sounds like when you put an induction kit on a car it just seems to grunt a lot when you open the throttle also would it be worth just lifting the needles a bit to see if it does anything and if it works then go and get some new jets also any ideas on what size jets to go for