Bob C
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| posted on 25/10/06 at 08:52 PM |
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R1 carb engine emissions
I just failed SVA on this - there were 2 issues, one was documentary proof of engine age. Is there a link to an engine number database, or are yamaha
likely to be helpful if I write to them, or would a local bike shop be able to provide it?
Have people been able to meet the requirements by adjusting standard carbs on the day or should I invest in some "fishtank valves"?
Note I was stymied a bit by brand new test kit at oldham which they were not very good at driving....
On the + side, R1, no airbox, sausage filter sticking out the top of the bonnet, MK 421 exhaust to a cat then a stock R1 can, passed the noise test at
7500rpm no bother. I was so stunned I heard myself asking " are you sure ?"... It sounded bloody loud to me but the meter said 100dB
cheers
Bob
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smart51
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| posted on 25/10/06 at 09:02 PM |
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All R1 engines are later than 98 and so mean a cat test for SVA. You shouldn't need to prove the engine's age as if you can't, you
have to to a cat test anyway. Proof of age is only for 95 and earlier engines.
I only needed to adjust the carb mixtures to pass SVA - once I'd fitted a bigger cat. The idle mixture screws provide all the control at 2500
RPM and no load. I could adjust right through the lambda range with room to spare. This gave low CO readings too. My only difficulty was getting HC
down, which I did, just, with a big cat.
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Bob C
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| posted on 25/10/06 at 09:20 PM |
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Cheers for that - I'd like to be SURE of a pass on the retest. I saw lambda readings of 0.6 so I believe I'm way lean - the mixture
screws are air bleed yes? so screw 'em in to richen the mixture?
Bob
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smart51
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| posted on 25/10/06 at 09:38 PM |
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Be careful screwing them in at all hard as the pin on the end of 2 of mine snapped off and I had to get new ones. Frustratingly you have to wind them
in and then back out to know that they're all the same. Otherwise you could be rich on 1 cylinder and lean on the others, giving really bad
results.
I think on the R1, the idle mixture screw flows frothy fuel - air and fuel to supplement the bit that comes out of the mains. I can't remember
if you have to turn them out to make them richer or not.
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kurt
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| posted on 30/10/06 at 08:17 AM |
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Mine passed by adusting the idle mixture screws. Screwing them out will richen it. If your reading is 0.6 then you are running rich so screw them
in. I was allowed to tweek mine at the test, it doesn't take much, we're talking an eigth to a quarter of a turn at a time. Also I
blanked of the Air Induction System with a valve in the pipe which would allow me bleed air in if necessary. I guess you've blanked yours off
if your not running the standard airbox. I also used a highflow performance CAT, which I could smell before it was hot enough to pass the test.
This also resulted in melting three of the SVA man's emissions probes!
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Bob C
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| posted on 30/10/06 at 10:47 AM |
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I wonder if there was something wrong with the kit then - I was seeing HC at 28ppm and CO vestigial but lambda 0.6 - does not compute........
Thanks for the info
Bob
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smart51
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| posted on 30/10/06 at 10:51 AM |
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Take your car down to a local tyre fitting and MOT type place when they're not to busy and use their exhaust gas machine. you can set up your
levels there. I did and they didn't charge me.
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kurt
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| posted on 31/10/06 at 07:53 AM |
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I second that. I got mine set up by my local garage and got a printout of the readings so I knew it should pass. However it still didn't pass
on the SVA man's machine, but I knew it was close so I could tweak it at the test. The garage did charge me a small fee, but then the exhaust
melted their gas analyser as well.
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