RobBrown
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| posted on 18/9/13 at 05:44 PM |
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Sorry - not the carbs spitting. I've had that too when it has been too lean
Just something that I hadn't really noticed before the engine blowing back though the carbs before anything gets started, whilst trying to turn
over. How does any fuel get into the cylinder if the engine is effectively blowing it away?
It just made me question whether the cam timing was right, once it started with the carb cleaner everything seemed to be OK, so timing must be OK.
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jacko
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| posted on 18/9/13 at 05:51 PM |
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quote:
Originally posted by RobBrown
Sorry - not the carbs spitting. I've had that too when it has been too lean
Just something that I hadn't really noticed before the engine blowing back though the carbs before anything gets started, whilst trying to turn
over. How does any fuel get into the cylinder if the engine is effectively blowing it away?
It just made me question whether the cam timing was right, once it started with the carb cleaner everything seemed to be OK, so timing must be OK.
From what you say it sounds like timing as you say, i would check all engine timing
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jacko
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| posted on 18/9/13 at 05:54 PM |
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quote:
Originally posted by jacko
quote:
Originally posted by RobBrown
Sorry - not the carbs spitting. I've had that too when it has been too lean
Just something that I hadn't really noticed before the engine blowing back though the carbs before anything gets started, whilst trying to turn
over. How does any fuel get into the cylinder if the engine is effectively blowing it away?
It just made me question whether the cam timing was right, once it started with the carb cleaner everything seemed to be OK, so timing must be OK.
From what you say it sounds like timing as you say, i would check all engine timing
Is the engine trying to stop turning over like a flat battery ? mine use to do this it was the timing advance too far on the dizzy
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RobBrown
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| posted on 18/9/13 at 06:04 PM |
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quote:
Originally posted by jacko
quote:
Originally posted by jacko
quote:
Originally posted by RobBrown
Sorry - not the carbs spitting. I've had that too when it has been too lean
Just something that I hadn't really noticed before the engine blowing back though the carbs before anything gets started, whilst trying to turn
over. How does any fuel get into the cylinder if the engine is effectively blowing it away?
It just made me question whether the cam timing was right, once it started with the carb cleaner everything seemed to be OK, so timing must be OK.
From what you say it sounds like timing as you say, i would check all engine timing
Is the engine trying to stop turning over like a flat battery ? mine use to do this it was the timing advance too far on the dizzy
No turning over freely. Fuel mixture is the problem. Adding the carb cleaner and it starts straight away, runs for a bit then stops, can get the RPM
high enough for the idle circuit not to be key and it runs.
Will try the bigger idle jets - you never know...
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sjmatthews
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| posted on 18/9/13 at 06:29 PM |
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It took me a couple of attempts to properly clear my idle jets. The holes in them are so small, and are very easily blocked again, so make sure the
fuel hoses or filter/s are not old and breaking down.
As far as i know, normally you don't need to increase idle jet sizes, so wouldn't advise drilling them just yet. My guess is
they're still blocked, or perhaps you've got leaks on the inlet manifold, drawing in too much air (test with wd40)?...
Keep us informed 
I'll be in the garage dear!
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RobBrown
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| posted on 18/9/13 at 06:44 PM |
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Don't panic, not drilling anything...
But some progress made...
New idle jets fitted, size 17.5 (which I had bought a few months ago, when I first started trying to get them running).
It now starts, but increases in RPM a little; runs for about 10-15 seconds then slowly comes back to rest.
Won't start again straight away, but after a few minutes does the same again, starts then dies
I can only get it to start with the idle mixture screw in a specific position. half a turn either way and it won't start as easily.
[Edited on 18/9/13 by RobBrown]
[Edited on 18/9/13 by RobBrown]
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jacko
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| posted on 18/9/13 at 07:28 PM |
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Are the diaphragms making a good seal
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RobBrown
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| posted on 18/9/13 at 07:40 PM |
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quote:
Originally posted by jacko
Are the diaphragms making a good seal
It's difficult to tell.
Before I cleaned the carbs I had sealed them with red grease, but since I've cleaned the carbs with cleaner I've left them on their
own.
I've tightened the manifold bolts further, got an extra half a turn out of each bolt - loathed to do anymore (might try and get some liquid
gasket, just to be sure and refit with that).
Found this which concurs with the suggestions here that it's an air leak somewhere on the inlet
useful link
Still not getting any reading out of the Carbtune for balancing, which again probably suggests an air leak, compromising the vacuum
Will re-grease the carb tops tomorrow.
Thanks for your help guys
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sjmatthews
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| posted on 20/9/13 at 04:40 PM |
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Any joy Rob?
Update please
I'll be in the garage dear!
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RobBrown
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| posted on 20/9/13 at 07:55 PM |
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I've got it starting but it is stopping after about 10 seconds, now not increasing in RPM.
I have taken the manifold off, discovered it had a slight bow, so have used a liquid gasket, rather than the paper one.
Applied red grease to top cover\diaphragm seal
I've drilled out the a\c to about 0.5mm (or thereabouts) - all my really small drill bits have broken, so not sure which one I've
used.
smells very rich still - I've got 185 jets fitted and needle on 2nd from top setting (I know BaileyPerformance suggested 2.0mm, but I've
not got a 2mm drill bit). I had needle on top position, but spat back and struggled to start.
Still suggests an air leak somewhere but can't now imagine where?
It won't start straight away after stopping - feels more like flooding than a vacuum leak, smells very rich as I say.
Incidentally no filter fitted yet.
Any more suggestions welcome.
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sjmatthews
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| posted on 20/9/13 at 08:26 PM |
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I wouldn't worry about main jet sizes at this stage, as they play no part in starting and idling which is the job of the pilot/idle jets (of
course).
Have you checked the plugs as soon as the engine stops? Are they wet, black, dry, white? Also, are the bowls empty? Do you know what the fuel
pressure is (should be <3psi)?
To check for induction leaks, you need to get the engine running (!) and spray wd40 around suspect areas. A rise in engine speed will indicate a leak
as the wd40 is drawn in and burnt.
Is it running on 4 cylinders, or obviously misfiring?...
Apologies - for so many questions
I'll be in the garage dear!
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RobBrown
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| posted on 20/9/13 at 09:22 PM |
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wd40 seems to not make any difference, for the 10 or so seconds the engine runs.
plugs look OK - one dry the other mildly moist, but not black or sooty.
Discovered one clogged with the liquid gasket from earlier - cleaned but made no difference.
Will only start with the choke on, but left on or released off makes no difference to the fact that it dies out after a while.
A bit of a long shot, but I read, via a google search, that coil failures of this type occurred occasionally. Might try looking for a new coil
tomorrow.
Just to add - running with an R1 fuel Pump - doesn't fill the bowls on the next start up, so not a lack of fuel issue as far as I can tell - Is
it possible to have too much pressure? with an R1 pump?
[Edited on 20/9/13 by RobBrown]
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RichardK
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| posted on 21/9/13 at 08:45 AM |
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Not sure about r1 carbs but mine had 3 very small holes that are usually covered by the butterfly disc when in the closed position that connect to the
mixture screw, so blew them out when the carbs were stripped and these view fine holes were blocked and gave exactly the problem you describe but
these were keihin carbs, also used compressed air to blow through, but can't express strongly how important it is to get the float height
correct on bike carbs, sometimes you can use a thin clear tube stuck on the drain bowl and then looped back up and taped to the side of the carb and
then open the drain screw and fuel will flow up the tube and settle at the same point of where it is inside which can be checked against the service
manual specs.
Hope you get it sorted.
Cheers
Rich
Gallery updated 11/01/2011
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RobBrown
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| posted on 21/9/13 at 04:20 PM |
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quote:
Originally posted by RichardK
... sometimes you can use a thin clear tube stuck on the drain bowl and then looped back up and taped to the side of the carb and then open the drain
screw and fuel will flow up the tube and settle at the same point of where it is inside which can be checked against the service manual specs.
Used this method against the same reference point on each carb. 1 and 3 were the same level and 2 and 4 were the same level. the difference in levels
between the two sets is 3mm.
Running the 30 or so seconds with the tube connected shows that the levels do not change on each of the carbs.
I've been running with the AFR fitted all morning trying to understand what's going on. At the point at which it cuts out there is no
obvious change in the AFR reading. Tweaking with the mixture screw I can get the longest run time to about 45 seconds, but it still ultimately dies. I
was hoping to see it go lean to confirm an air leak, but nothing.
When I say it runs for 45 seconds, its running at 2.5k RPM. It's at the low RPM that it cuts out.
AFR reading the leaning out towards the end is after it has started struggling
 
AFR reading cutting out after
Later it did this before stopping:
 
cutting out
[Edited on 21/9/13 by RobBrown]
[Edited on 21/9/13 by RobBrown]
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BaileyPerformance
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| posted on 21/9/13 at 04:45 PM |
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are you sure your ignition is ok?
connect a strobe light to one of the HT leads, run the engine and watch the strobe, make sure the strobe keeps flashing as the engine dies to confirm
ignition is OK
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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RobBrown
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| posted on 21/9/13 at 05:00 PM |
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Yes, even slows as the engine slowly dies
Could it be bin settings on the MegaJolt and the advance? Only because I've noticed the sudden drop in advance between each bin.
Running at 2.5k the advance is 25,
but my bin jumps in steps of 1000RPM
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davidimurray
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| posted on 21/9/13 at 05:19 PM |
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Only just spotted this read so a few ideas based on my nightmares setting mine up.
When you say you have cleaned the jets etc have you left them overnight in carb cleaner to soak.I blew mine through numerous time w compressed air and
they kept blocking. I was amazed at how much dirt the cleaner got out.
Where are your float heigh levels relative to the jet to where the jet enters the carb. The level should be below this.
When you blip the throttle do all 4 diaphragms raise?
How close is the balance across all 4- they need to be very close.
My pinto has a bit of a missfire pop from the exhaust at anything above an AFR of 13, 12 .5 seems to be about perfect, but it is then a bit high on
co. I've heard of the same thing on other pintos
Does the engine idle on the throttle? Any miss firing or popping back through the carb?
Gallery 1 http://www.facebook.com/media/set/?set=a.116893465324.130778.601005324
Gallery 2 http://www.facebook.com/media/set/?set=a.245243755324.181913.601005324&l=a9831a9319
Gallery 3 http://www.facebook.com/media/set/?set=a.440671625324.232627.601005324&l=3f0d42c523
Gallery 4 http://www.facebook.com/media/set/?set=a.490098255324.297598.601005324&l=efb083b7df
Gallery 5 http://www.facebook.com/media/set/?set=a.10150244028550325.366987.601005324&l=583fd5cd3a
Gallery 6 http://www.facebook.com/media/set/?set=a.10150550640070325.430417.601005324&type=3&l=fe779b358c
Duratec Engine Swap https://www.facebook.com/media/set/?set=a.10152527759580325.1073741828.601005324&type=1&l=40aae5e72f " target="_blank"> https://www.facebook.com/media/set/?set=a.10152527759580325.1073741828.601005324&type=1&l=40aae5e72f
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RobBrown
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| posted on 21/9/13 at 05:43 PM |
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quote:
Originally posted by davidimurray
Only just spotted this read so a few ideas based on my nightmares setting mine up.
When you say you have cleaned the jets etc have you left them overnight in carb cleaner to soak.I blew mine through numerous time w compressed air and
they kept blocking. I was amazed at how much dirt the cleaner got out.
Where are your float heigh levels relative to the jet to where the jet enters the carb. The level should be below this.
When you blip the throttle do all 4 diaphragms raise?
How close is the balance across all 4- they need to be very close.
My pinto has a bit of a missfire pop from the exhaust at anything above an AFR of 13, 12 .5 seems to be about perfect, but it is then a bit high on
co. I've heard of the same thing on other pintos
Does the engine idle on the throttle? Any miss firing or popping back through the carb?
Thanks for your help
No - not left them in overnight. the Main jets are new, so would only be the pilot and air jet. Could try this tonight
The engine will run if the throttle is fully opened up, just won't idle if left at 10% TPS or lower - having said that is throttle adjusted
higher it won't run indefinitely.
fuel level is higher than the join between the bowl and the carb. not measured float itself yet.
I can't get my Carbtune to register at the moment, to check balance - not sure whether it's related or a duff carbtune, which has been
sitting around for a couple of years.
A few misfire pops at different times, mainly when I open the throttle.
All four sliders move when I blip the throttle.
My main issue is the cutting out after a very short amount of time.
The only significant change I've made recently is the MegaJolt, because I thought my issues were to do with the Dizzy and the timing - but that
seems to firing OK.
[Edited on 21/9/13 by RobBrown]
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jacko
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| posted on 21/9/13 at 07:00 PM |
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I know nothing about megajolt could it be that that's cutting out and not the carbs ?
If it was me i would refit the dizzy and try that again
Jacko
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RobBrown
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| posted on 21/9/13 at 07:09 PM |
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quote:
Originally posted by jacko
I know nothing about megajolt could it be that that's cutting out and not the carbs ?
If it was me i would refit the dizzy and try that again
Jacko
I really struggled with the Dizzy - I could never get it into the right position to get even the faintest hint of a start. Although it could have just
been mirroring the same issues I have now.
I've also taken out all the wiring and the original module, so not an option now that the MJ is in.
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jacko
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| posted on 21/9/13 at 07:23 PM |
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I wish you lived in hull i would have come and looked at it for you
Dose the engine stop as if the electrics have cut or if its run / running out of petrol
Jacko
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BaileyPerformance
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| posted on 21/9/13 at 07:32 PM |
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Unplug your megajolt, the EDIS will default to fixed timing of 10 degrees which is find to get it running.
....this assumes you have installed the trigger wheel correctly as we have seen loads that are in the wrong place or badly mounted vr sensor
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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davidimurray
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| posted on 21/9/13 at 07:41 PM |
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Definitely try removing the idle and pilots and soaking in carb cleaner over night. I was amazed at the difference it made to mine. Mine are zx6r but
after blowing them through my idle screws had to be 4-5 turns out, after soaking in cleaner I now only have them 2.5 turns out. My pilots also kept
blocking and again carb cleaner sorted them out. At the same time I would also spray some carb cleaner down the carb and check that it drips down
through the idle and pilot passages.
Really stupid question, but have you confirmed the fuel pump is running constantly. It couldn't have been wired to the start postion by accident
could it? Next time it dies try opening the screws on all the float bowls and seeing if there is fuel in all of them.
I assume that you have the throttle stop adjuster fitted.May sound stupid but I have seen carbs for sale with them missing
If it runs at full throttle then I wouldn't worry about the mains yet and it would point to a problem with the idle/pilots. Popping back through
the carbs on mine was as a result of a lean miss fire and carb balance.
Are you using the throttle to start the engine?
Keep at it, took me a while to sort but now starts instantly with or without choke depending on the temp.Can even get a 20p piece balanced on the
rocker cover.
I probably have some AFR traces for starts and you're welcome to a copy of my jolt map if it helps. Mine is an 1800 but won't be far
off.
quote:
Originally posted by RobBrown
quote:
Originally posted by davidimurray
Only just spotted this read so a few ideas based on my nightmares setting mine up.
When you say you have cleaned the jets etc have you left them overnight in carb cleaner to soak.I blew mine through numerous time w compressed air and
they kept blocking. I was amazed at how much dirt the cleaner got out.
Where are your float heigh levels relative to the jet to where the jet enters the carb. The level should be below this.
When you blip the throttle do all 4 diaphragms raise?
How close is the balance across all 4- they need to be very close.
My pinto has a bit of a missfire pop from the exhaust at anything above an AFR of 13, 12 .5 seems to be about perfect, but it is then a bit high on
co. I've heard of the same thing on other pintos
Does the engine idle on the throttle? Any miss firing or popping back through the carb?
Thanks for your help
No - not left them in overnight. the Main jets are new, so would only be the pilot and air jet. Could try this tonight
The engine will run if the throttle is fully opened up, just won't idle if left at 10% TPS or lower - having said that is throttle adjusted
higher it won't run indefinitely.
fuel level is higher than the join between the bowl and the carb. not measured float itself yet.
I can't get my Carbtune to register at the moment, to check balance - not sure whether it's related or a duff carbtune, which has been
sitting around for a couple of years.
A few misfire pops at different times, mainly when I open the throttle.
All four sliders move when I blip the throttle.
My main issue is the cutting out after a very short amount of time.
The only significant change I've made recently is the MegaJolt, because I thought my issues were to do with the Dizzy and the timing - but that
seems to firing OK.
[Edited on 21/9/13 by RobBrown]
Gallery 1 http://www.facebook.com/media/set/?set=a.116893465324.130778.601005324
Gallery 2 http://www.facebook.com/media/set/?set=a.245243755324.181913.601005324&l=a9831a9319
Gallery 3 http://www.facebook.com/media/set/?set=a.440671625324.232627.601005324&l=3f0d42c523
Gallery 4 http://www.facebook.com/media/set/?set=a.490098255324.297598.601005324&l=efb083b7df
Gallery 5 http://www.facebook.com/media/set/?set=a.10150244028550325.366987.601005324&l=583fd5cd3a
Gallery 6 http://www.facebook.com/media/set/?set=a.10150550640070325.430417.601005324&type=3&l=fe779b358c
Duratec Engine Swap https://www.facebook.com/media/set/?set=a.10152527759580325.1073741828.601005324&type=1&l=40aae5e72f " target="_blank"> https://www.facebook.com/media/set/?set=a.10152527759580325.1073741828.601005324&type=1&l=40aae5e72f
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RobBrown
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| posted on 21/9/13 at 07:47 PM |
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quote:
Originally posted by BaileyPerformance
Unplug your megajolt, the EDIS will default to fixed timing of 10 degrees which is find to get it running.
....this assumes you have installed the trigger wheel correctly as we have seen loads that are in the wrong place or badly mounted vr sensor
started first time - but then cut out after about 15 or so seconds, as it has been doing all day.
Interestingly wouldn't start straight afterwards.
To me this tells me that it's nothing to do with jet sizes or needle positions for now, there's something else going on which is causing
the stopping. Either flooding, or the spark stopping.
Flooding would explain why it doesn't start straight away - wouldn't it?
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RobBrown
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| posted on 21/9/13 at 07:59 PM |
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quote:
Originally posted by jacko
Dose the engine stop as if the electrics have cut or if its run / running out of petrol
it slows as if it's running out of petrol - the float bowls remain full though as I've had a clear tube attached to each one when it runs.
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