aka Keith
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 posted on 6/7/15 at 06:02 PM |
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will not run on 4 cyclinders
After blowing a the head gasket on my zx9r engine BEC, I have replaced the gasket and replaced the head (easier and quicker than getting the old one
skimmed).
But now I cannot get the 4th cylinder to fire,
I am getting a spark,
I have done the shims
The compression looks the same across all the cylinders and
I have given the carb an overhaul and replaced the need float valve
But I cannot get the engine to fire up on 4 cylinders.
Anyone had anything similar, any ideas as to what to check next before I take a 4x2 to the car and do a Basil Fawlty.
Cheers
Craig
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mark chandler
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| posted on 6/7/15 at 06:19 PM |
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Are the HT leads correct? Sounds obvious but I have fallen into this simple trap
When three, is the 4th plug wet?
Swap plugs around, swap HT leads around and see if the problem follows these.
Regards Mark
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aka Keith
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| posted on 6/7/15 at 06:26 PM |
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quote:
Originally posted by mark chandler
Are the HT leads correct? Sounds obvious but I have fallen into this simple trap
When three, is the 4th plug wet?
Swap plugs around, swap HT leads around and see if the problem follows these.
Regards Mark
Mark, the plugs as you know are coil on lug efforts. all have been marked and numbered since I got the engine years ago, and 4th COP is def on 4th
cylinder.
4th plug is not wet, but I have done the float levels, the float needles and cleaned the 4th carb more times that I care to imagine.
Swapping plugs and coils over makes no difference,
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ian locostzx9rc2
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| posted on 6/7/15 at 06:51 PM |
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Try putting a little bit of fuel direct through no 4 carb .
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aka Keith
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| posted on 6/7/15 at 07:12 PM |
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quote:
Originally posted by ian locostzx9rc2
Try putting a little bit of fuel direct through no 4 carb .
How do I do that?
If it runs, then it is carb issue yes?
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ian locostzx9rc2
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| posted on 6/7/15 at 07:40 PM |
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Just pour a bit down the carb only a little if it runs then it's a carb issue
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mark chandler
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| posted on 6/7/15 at 07:42 PM |
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Get it running then dribble a cap full of fuel into the mouth of the dead carb, if it picks up then you have a blocked jet or similar.
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big-vee-twin
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| posted on 6/7/15 at 08:31 PM |
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Could use a spray can of easy start on fourth pot to give it a kick if you don't fancy pouring fuel in.
Duratec Engine is fitted, MS2 Extra V3 is assembled and tested, engine running, car now built. IVA passed 26/02/2016
http://www.triangleltd.com
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aka Keith
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| posted on 7/7/15 at 05:11 AM |
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Thanks gents, will try dribbling a little fuel in when it is running on 3 and will let you know what happens.
cheers
Craig
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40inches
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| posted on 7/7/15 at 09:22 AM |
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Doesn't No4 fire at all? Even at WOT or anything in between?
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aka Keith
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| posted on 7/7/15 at 12:48 PM |
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Thanks Gents, I poured a little petrol into the 4th carb when it was running and it fired up, so looks like I need to the give the carbs another good
going over.
what fun.
Cheers
Craig
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owelly
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| posted on 7/7/15 at 12:50 PM |
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Any air-leaks on that pot? If it's sucking air, it may be too lean to fire or not slurping any fuel at all.
http://www.ppcmag.co.uk
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aka Keith
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| posted on 7/7/15 at 12:54 PM |
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Owelly,
when you say air leaks, could you elaborate?
Cheers
Craig
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adithorp
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| posted on 7/7/15 at 01:25 PM |
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quote:
Originally posted by aka Keith
Owelly,
when you say air leaks, could you elaborate?
Cheers
Craig
Like a vac' pipe on that carb pulled off/split or the mounting rubber mis-aligned or not tight.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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aka Keith
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| posted on 7/7/15 at 01:42 PM |
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Ahhh I had checked them all, previously (ie just last week, but will check again).
Cheers
Craig
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40inches
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| posted on 7/7/15 at 02:15 PM |
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If you link the vac outlets on carbs 1&4 and 2&3 together the engine will run smoother at low revs, plus it makes it easier to balance if the
tubing is already connected 
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aka Keith
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| posted on 7/7/15 at 02:47 PM |
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quote:
Originally posted by 40inches
If you link the vac outlets on carbs 1&4 and 2&3 together the engine will run smoother at low revs, plus it makes it easier to balance if the
tubing is already connected
40inches, had that done on the car since I got it about 6 years ago. but thanks.
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aka Keith
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| posted on 7/7/15 at 05:04 PM |
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stumped yet again.....
replaced the hoses on the carb vacuum take offs, took the 4th carb to bits, soaked the pilot jet and idle screw adjuster, and main jet, blasted the
body and parts in carb cleaner and checked the float heights
put it all back together and still it will not run.
what is left?
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dave_424
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| posted on 7/7/15 at 05:33 PM |
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Open the float bowl drain on the number 4 carb to check that it's getting fuel.
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aka Keith
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| posted on 7/7/15 at 05:48 PM |
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quote:
Originally posted by dave_424
Open the float bowl drain on the number 4 carb to check that it's getting fuel.
Dave, it is getting fuel, just opened the drains, and got the same amount of fuel from all the carbs. It must be the needles ro something.
thing is, these carbs were working just fine when I blew the headgasket, I replaced the headgasket and now it will not fire on 4th.
Cheers
Craig
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dave_424
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| posted on 7/7/15 at 05:54 PM |
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Then I would have thought either a jet/fuel passage is blocked not allowing fuel out, or there is a split or leak in the carb rubber that isn't
allowing enough air velocity through the carb to draw fuel up
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aka Keith
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| posted on 7/7/15 at 06:46 PM |
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quote:
Originally posted by dave_424
Then I would have thought either a jet/fuel passage is blocked not allowing fuel out, or there is a split or leak in the carb rubber that isn't
allowing enough air velocity through the carb to draw fuel up
cheers dave, I had not thought of the carb rubber. so have just gone out to the garage and replaced the carb inlet rubber and stuck the idle screw and
jet in carb cleaner again.
Getting a bit late to annoy the neighbours with starting the car up, so will hopefully get back at it tomorrow night and give you all an update.
Cheers
Craig
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dave_424
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| posted on 7/7/15 at 07:45 PM |
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If I remember there is also an oring in the car rubber for it to seal against the head
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aka Keith
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| posted on 10/7/15 at 11:58 AM |
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So I wanted to give every one a quick update. I replaced the carb rubbers including the o ring sealers between rubber and block, then I stripped out a
working carb and stuck it in carb number 4, result, it idled on all 4.
left it overnight and started the re-assemble the car today, whipped the carbs off as I had got the idle control wrapped around some pipes, stuck
everything back on, and now she only idles on cylinders 1 & 2.
I have drained the carb bowls in 3 and 4 and there was petrol, in them.
giving up, some please give me some inspiration. loosing all faith in it at the moment.
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dave_424
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| posted on 10/7/15 at 12:06 PM |
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Don't give up now, you are on the right track. You've had it running on all 4 now so you have just got to replicate that when the car is
all assembled.
It's only going to be a small simple thing I expect and you will be back up and running
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