matt_gsxr
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| posted on 8/5/09 at 11:31 AM |
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Overfilling with oil and HC's
Hi there chaps,
I am still struggling with SVA emissions. The HC's are mental (6-7k ppm, 1.2k is a pass) but my CO isn't too bad (i.e. 4%, 3.5% is a
pass).
Now I know these figures are awful (part of the problem relates to running very rich at wider throttle openings, and filling the exhaust with HC when
purging!). So I think I need to drop the needles on the mains (quite a lot of dropping needed). Also this may be leading to choked up plugs which
may be causing some problems, but 7000 is a lot more than 1200.
I am quite a healthy overfilling of the oil, and I wondered whether this was a recognised source of elevated HC's. Obviously I may have leaking
valve stems, or bore wear, but I am trying to think of things that are locost!!! I will get a compression tester tonight to investigate my biggest
worry. Colortune gives a reasonable blue.
Any thoughts appreciated,
Matt
p.s. any recommendations of a "specialist" around Oxford with equipment and experience for bike carbs?
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Guinness
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| posted on 8/5/09 at 11:45 AM |
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I had a similar fail at my SVA with very high unburnt hydrocarbons in the mix.
I think it was unburnt fuel in the exhaust packing. My logic went that in all of my attempts at starting it during the build there was un-burnt fuel
entering the can. On the few occasions that I ran the car up to temp, I don't think the can ever got hot enough to evapourate all the fuel
out.
Between my fail and my re-test we fiddled around with the carbs, but also went on a few decent drives (to carb specialists!) which IMHO helped!
Mike
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matt_gsxr
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| posted on 8/5/09 at 11:49 AM |
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very interesting, and quite possible.
I was a bit down when I read the numbers on the machine this morning. This has really cheered me up, thank-you, even if it doesn't turn out to
be my solution I am feeling better with the world.
Matt
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pewe
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| posted on 8/5/09 at 11:57 AM |
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Also worth checking the timing. If too far advanced or retarded you won't achieve decent numbers.
BOL.
Cheers, Pewe 
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matt_gsxr
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| posted on 8/5/09 at 12:02 PM |
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yeah I was going to check the timing tonight. On the GSXR1100 timing isn't adjustable, but I have seen instructions on how to advance it by
"stretching" holes and such.
This engine is 15years old, so I am sure it has some stories, so its worth a look.
Advancing the timing can increase the HC's if I remember correctly (7000 is a very big number though), so I will take a good look.
Thanks,
Matt
[Edited on 8/5/09 by matt_gsxr]
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SteveWalker
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| posted on 8/5/09 at 12:41 PM |
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I went to a show a few years back and knew I was low on oil, I topped up, but overdid it and had neither the time or facilities to drain some out. The
car was fine unless I accelerated hard and then I got large bursts of blue smoke which was most definitely HC rich!
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bassett
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| posted on 8/5/09 at 12:47 PM |
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Its been recommended to myself to make sure the oil is spot on and doing a change to remove any fuel in the oil as my emissions are 2-3x what they
should be. New plugs cant hurt unless you already have them if not give the current ones a good clean to promote a cleaner burn.
[Edited on 8/5/09 by bassett]
My MNR Blog Updated Jan 2010 - Track Day Prep Begins!
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DRC INDY 7
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| posted on 8/5/09 at 12:56 PM |
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Just changed the oil on mine today cause it looked a bit black with 900 miles on the clock i last changed it aug 2008 with 192 miles on
that can make a big difference to co/hc levels
https://www.facebook.com/groups/462610273778799/
Puddle Dodgers Club
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matt_gsxr
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| posted on 8/5/09 at 01:25 PM |
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thanks for those good tips.
I think the core of my problem is that my carbs came from some sidecar racers, so it appears that they are set a lot on the rich side of things.
I wouldn't have thought that the engine has run sufficiently for the oil to be polluted. I haven't gone anywhere and have only ever used
maybe 3gallons for SVA and set-up (obviously insufficient set-up). I guess the additional fuel comes into the carbs fromt he oil via the camshaft
breather, in which case I can just vent that into a bottle. I will give it a sniff and see what is coming out of it!
I have mostly been tuning the mixture with the airbox off (too difficult otherwise) so this is something that could affect things.
As part of my multitude of remedials I will lower the oil level a bit (can't do any harm). The plugs are pretty new and I regularly scrub them.
I will check the ignition timing (the valves are either right, or broken, so I will hope for the best there). Once I have sorted my large throttle
opening fueling I will go for a blast to a local garage to investigate emissions (whilst sorting my exhaust).
If all that doesn't work then I'll have to put my hand in my pocket and get an expert.
Thanks for these tips.
Matt
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idl1975
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| posted on 8/5/09 at 02:30 PM |
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You may still be able to get specific slotted sprockets from a GSX-R tuner - some of the drag or turbo-bike specialists may still stock them for the
1100. Kosman or Holeshot?
quote:
Originally posted by matt_gsxr
yeah I was going to check the timing tonight. On the GSXR1100 timing isn't adjustable, but I have seen instructions on how to advance it by
"stretching" holes and such.
This engine is 15years old, so I am sure it has some stories, so its worth a look.
Advancing the timing can increase the HC's if I remember correctly (7000 is a very big number though), so I will take a good look.
Thanks,
Matt
[Edited on 8/5/09 by matt_gsxr]
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matt_gsxr
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| posted on 8/5/09 at 10:15 PM |
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Update
Ignition timing looks stock (i.e. it is fixed and all the parts carry suzuki numbers). I have a Dyna 2000 unit that I might fit. It gives me the
chance to change the ignition which is always fun!
Crankcase vent smells a bit when engine gets up to temperature, but not "fall over" strong, just a bit wiffy. I assume my oil isn't
contaminated with fuel. Probably change it anyway.
Oil level lowered (not too difficult that!)
Dropped the needles by a load (i.e. 3 slots) the engine runs up a bit better (subject to annoying the neighbours) but still fouls the plugs. I am
going to invest in some replacement jets (I am entering the world of jets!!). I am also going to take wine around to the neighbs before they whine at
me.
UPDATE: I order a replacement needle from Suzuki (worth its weight in gold) and it turns out that my needles are non-standard. So I have splashed out
on a Dynojet kit, which allows me to get the springs, needles and jets to a place that I have a chance of understanding. I am going to take the
weekend off from this stuff!
While I am stripping the carbs I will lower the float level which might also help.
Compression test tomorrow. Compression turned out good 160psi to 175psi across the 4 cylinders, which is well within the spec. I popped some oil in
the lowest one, and it only increased the pressure by 10psi, so rings look like they are fine (great news).
Took off the exhaust. It is a MK one and is filled with glass fibre (or somesuch). Basically it was very wiffy. The silencer with loads of fuel in
it hypothesis is looking good. I put a butane torch in one end and heated the whole thing up, and loads of nasty pongs came out. Basically these
are not going to help my HC scores.
I will get my engine running right at high throttle openings, and then get some real heat into the silencer.
Light at end of tunnel (or perhaps an oncoming train).
Matt
[Edited on 9/5/09 by matt_gsxr]
[Edited on 10/5/09 by matt_gsxr]
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matt_gsxr
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| posted on 14/6/09 at 10:20 PM |
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I don't know whether it is poor ettiquette to keep replying to ones own post, but if it is then sorry.
My saga continues.
When swapping the needles and jets for the dynojet ones it turns out that I had the biggest jets in the world installed. Well they were big. So that
might explain some of the over fueling. FYI the dynojet kit was a bit rubbish, not many bits and performance curves that don't really change
(they didn't put these instructions on their website, and I can see why). Never mind.
Subsequent to the above, I got an LC-1 (AFR sensor), and have been looking at its outputs. I am really struggling to get my AFR to 14.7 whilst
idling. Loads of folk suggest that this should be easy, but on a GSXR1100 with 40mm carbs it isn't.
I seem to be able to get around 13.5 (for SVA), but if I try and get it higher I pick up various misfires. The AFR jumps around like crazy (+/- 0.3)
as I assume the fuel isn't well mixed with the air. I don't have a sensor per cylinder (such is the shame), so this is mighty
challenging. I think Cloudy had the same problems with his GSXR1100, and scraped through the SVA in the end.
I don't know whether to accelerate my Megasquirt plans, as I am confident that the problem is all to do with the poor idle quality of these big
carbs, or whether to persevere.
Not sure what to do, but I am bored of colortuning the engine, and of plug swapping.
Any thoughts appreciated.
Matt
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bassett
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| posted on 15/6/09 at 08:15 PM |
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Sorted mine last week when it passed at sva. New oil at bang on the right level, fuel injector cleaner, tesco jungle juice, NGK iriduim plugs, new air
temp sensor(or what ever the airbox mounted one does) and the results were fantastic 0% CO2, 60 something HC and lambda good. However it is FI so
helps having the power commander helps. How bigs your cat?
Adam
My MNR Blog Updated Jan 2010 - Track Day Prep Begins!
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matt_gsxr
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| posted on 16/6/09 at 09:05 AM |
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Adam,
Well done for getting through.
In my case I have a whole set of different problems,
pre 95,
no cat.,
so 1200ppm and 3.5% are the threshold values.
I think the fundamental problem is that the carbs are too big (they are standard, but they are the largest that Suzuki shipped with this engine and
the idle is pants). I have done lots of messing with mixtures and stuff and done a load of balancing. The US and California spec ones are different
and the timing on those was quite different too (their emissions are more challenging).
The AFR jumps all over the place (I have an LC-1 as the plan it to FI it in the long term), so it goes between lean misfires and too rich at the drop
of a hat.
The good thing about the LC-1 is that I can adjust things and review the logs. It seems like Iridium plugs are a good deal better (fewer misfires).
Also I should be able to connect it to a 'scope and look at the individual exhaust gas packets and hence tune each cylinder if I can trigger it
off the ignition timing.
ALternatively, I have build a megasquirt, I have got some throttle bodies, fuel rail, and all the rubber bigs to keep the air in the right places.
Also I have added the appropriate ignition trigger, and temperature sensors for water and air, so all I need to do to get megasquirt working is to
sort out the fueling, and connect up a few wire.
For fueling I have a pump and adapter plate for my tank, so even that isn't rocket science, although drilling into a perfectly good fuel tank
doesn't appeal much. The only problem is tuning the megasquirt when the car isn't road legal as although I have an LC-1 I can't
drive it anywhere to optimise the AFR, and I don't know anyone with an appropriate gsxr1100 map.
Ho, hum.
Matt
p.s. I have to remind myself that I didn't do this because I wanted it to be easy, or because I don't have a car already!
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Guinness
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| posted on 16/6/09 at 06:59 PM |
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Hi Matt
Unburnt fuel in the can!
Is there any chance you can get a smaller set of carbs off ebay? Just for the SVA test?
Mike
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matt_gsxr
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| posted on 17/6/09 at 11:02 AM |
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Mike,
Unburnt fuel is definitely a consideration, but now I have AFR (before can) I think I can eliminate it from my present readings. I think this was
certainly a problem during prior tests, and unless I burn it all of will be a problem for the next one.
I have paid up my insurance and booked an appointment with the gas tester at a local garage. Hopefully I can give it a bit of a blast on the way
which will burn off lots of nasties.
I managed to connect up megasquirt and so have nice datalogs of everything, which is interesting.
I think that I may have filled the combustion chamber with carbon, as I get nasty over-running, and this may be causing some pre-ignition that is
making setting the engine up difficult. Giving the engine a blast tomorrow may help a bit with this.
There are some smaller carbs that fit this model (38mm instead of 40mm, they even did 36mm but I haven't seen them for sale much) and I might
see what I can find. That was something that I was thinking of doing. It is a pretty cheap solution, as 2nd hand carbs are cheap as chips, and I can
always re-sell them.
Thanks for your ideas,
Matt
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matt_gsxr
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| posted on 18/6/09 at 01:12 PM |
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Great day
UPDATE: good news
Drove my car for the first time today to 'local' garage to get emissions tested. What a buzz (in every sense!).
The night before I had applied some "snake-oil decoking solution" which in addition to creating masses of smoke seemed to improve the
engines mood (less pre-ignition), and had carefully balanced the carbs. and set the idle screws to 2.25 turns (+0.25 for the front one to keep it
happy).
Fresh fuel and 10miles to garage so things warmed up reasonably.
At 1150rpm I got 1500ppm for HC, and 0.3% for CO. I suspected it might be a lean missfire (giving the HC's) but richening it up moved it the
wrong way.
So, it looks like the big carbs are at fault.
At 2000rpm, I managed to lean it off enough (probably 2turns on the idle screws, which is suzuki stock) to get the HC's down to 850ppm, CO still
low. CO2 at 6% (or so).
So, it should pass the test. I am not going to touch anything, and hope for identical weather conditions! It is all a bit sensitive.
I need to drive the thing carefully, as I think it is all a bit lean. But I will get it tested first and then sort these things out. For the time
being I don't want to adjust anything.
Matt
p.s. great first drive. Loads of power, loads of wind, loads of torque, only 1 stall (I had previously been using 2nd gear dohh!). A great day.
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matt_gsxr
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| posted on 27/6/09 at 02:40 PM |
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Passed SVA with 1049ppm and 0.4% CO as idle.
Actually it failed at the first test even at the 2000rpm idle, but passed when we ran a second test at the end.
SVA man was very helpful (after he had overheated the engine during the speedo test!)
End of saga.
Take home message:
1) drive to SVA test to clean out exhaust/engine of "spare HC's".
2) balance carbs to perfection.
3) set idle screws up as stock and then tweak at a friendly garage (AFR gauge isn't much use for this task).
4) Big (40mm) carbs are a challenge for the HC's even when the requirement is 1200ppm.
Matt
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