DCS light flashing !!! "HELP"

Myself i'm not making nothing......i'm just saying on a stock sled you
should be able to make it work on fresh pump fuel and not need race gas.....
 

The TPS only adds/subtracts to the timing curve in the mid range cruising, it has no effect at idle or WOT, none. It can only affect the timing a couple degrees. Your problem most likely was the engine has begun to get blow by 3000 miles if the rings have never been changed resulting in a changed fuel mixture, your contaminating the fresh fuel charge with exh gasses, this will be evident by the black on the sides of the pistons skirt and some black on the bottom of the transfer ports, as it is inhaling exh fumes. The engine over time will lose power and not be able to pull the same amount of clutch weight, this is normal. This is the reason why I try to explain to people that rings are one of the most important componets in a 2 stroke, the piston and rings are the heart of the engine.
The clutching can determine how hard a motor is loaded but it doesnt create detonation, detonation is created by low octane, lean jetting. The engine could be loaded harder with a aggressive clutch set up but its still the octane level and jetting that determines the detonation, it just shows up more pronounced but if you could run the sled long enuff of a distance with low load clutching the light would also come on. Richer jetting will cool the piston crown more with excessive fuel and keep the light off. There is other things such as head set up, piston crown, squish clearance and so forth that can be factors in a detonation prone engine but its not needed in this discussion as we are talking about stock engines.

Daman: do you have anything constructive to add to the conversation here??or only arguing something you dont even know how it works, have owned one or even worked on one? please enlighten us. Your comments get a bit old as they are completely warrantless to thier validity.
 
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The needles simply need both shims under the clip and it solves the problem, most people dont realize but 90 % of all burn downs and problems happen on the needle, not the main jet. Do you realize your not fully into the main jet circuit until about 600feet out from a point? All carb circuits overlap each other and 90 percent of trail riding your not running constant wide open throttle further then 600 feet long unless all you do is ride roads and lakes. The conditions you ran the sled in also play a role, unless something changed is done same exact day, same temp, same everything its not a direct comparison.
 
I just went and read all 60 something post and not in 1 post did anyone touch the needles on their sled, only the mains, well.. if your not running far enuff to be only on the mains the light will go off, because your running on the lean needle settings and the rich mains, its a combo of both circuits, and the needle is more of a player then the main is, he is the one who controls how much of the mains orfice will be exposed. Like I said before, you need to be a good 600 feet long wide open throttle to be on the main jet circuit alone, otherwise the mr. lean needle is involved!

I saw this post and read it today and see there is 60 post and none can solve the problem, its not rocket science. I do these sleds all the time and I pump up the power and compression, big bores and all, and never have any problems with DCS, its a great feature. If its coming on its doing its job! Its telling you your not in tune for the conditions or the load your applying to the engine. Use it as a tool to tune your sled to go faster.

Remember one thing, lean is mean in a short race only, it takes fuel to get mph!! MPH is indictive of hp output and lean jets will not make more topend hp/mph for that matter, not for very long!! Thats why anyone can flash a big hp number on a dyno with lean jetting, but take that same short 5 second sweep run and make it 10-11 seconds long and youll see it go the other way! Or better yet the sled will not run out in the field because the jetting is too lean!! apply more load to a engine it needs more fuel not less.

If you guys would have seen some of the piston tops I ran on the asphalt with rich jetting at 80-90 degree temps youd have said "that things pig rich", and it was, with about a 1/2 inch of wash all the way around the crown with only a good 50 cent peice of carbon in the center of piston crown, rest is all bare alum looking, wet and shiny! Thats where the best MPH is! It takes fuel to run up top! by jetting the sled down to get carbon on the whole top the sled lost 4-6mph off topend, slowed the mph from 128 down to to 122-124mph. Put back the rich jets.....bam... right back up to 128mph! Just some food for thought for you when your out testing!
 
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NOW YOU HAVE A GREAT TUNER EXPLAINING EXACTLY WHAT YA NEED TO KNOW ABOUT DCS. BUT GUYS, EXHAUST SPRINGS AND RIVETS. ALITTLE COMMON SENSE HERE. !!!!! DON, GOD BLESS YA. 3:16 (yammie tony)
 
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I agree with yammiman, jetting cannot be the only variable. How can you blaim on jetting when one clutch set up makes the dcs blink and the other doesn't on the same day in the same temps? (I've experienced that).
 
mrviper700 said:
The needles simply need both shims under the clip and it solves the problem, most people dont realize but 90 % of all burn downs and problems happen on the needle, not the main jet. Do you realize your not fully into the main jet circuit until about 600feet out from a point? All carb circuits overlap each other and 90 percent of trail riding your not running constant wide open throttle further then 600 feet long unless all you do is ride roads and lakes. The conditions you ran the sled in also play a role, unless something changed is done same exact day, same temp, same everything its not a direct comparison.
Click to expand...
so true - motors don't burn down when they are pinned, they burn down when you start letting off and the needle is back in the hole.
 
Norweigan: heres your answer from post below:
The clutching can determine how hard a motor is loaded but it doesnt create detonation, detonation is created by low octane, lean jetting. The engine could be loaded harder with a aggressive clutch set up but its still the octane level and jetting that determines the detonation, it just shows up more pronounced but if you could run the sled long enuff of a distance with low load clutching the light would also come on.

The clutching either reveals the lean condition or covers it up, its all about how aggressive it is and how it makes the motor work. Still comes down to the engine is lean thats why the light is going off!!

Yammiman, just because the needles are in the same posistion on a 01-02 doesnt mean you never had detonation on a 01!! Happens all the time, people burn down srxs all the time, you just never had a DCS system to alert you to it before it just bogs out and coast to a stop!

This is my last reply to this, I think its been covered more then enuff and you guys have all your answers right here. Its up to you if you use the information to your advantage or just continue to chase your tail. All I can do is give you the information and how to correct the problem, if you think its loose rivets, cdi boxs, faulty yamaha engineering and solar eclipses causing the problem then your on your own.
 
Still, the conclusion is that if not clutched like the motor/dcs likes it, it makes the dcs go off
 
REMEBER MANY 2000 SRX,s BURNED AFTER WOT RUNS ACROSS LAKES AND NO DCS TO SAVE IT OR OWNER. COULD BE WHY JETTING SPEC CHANGED IN 01 AND DCS CAME OUT IN 02. NAW!!!!! LOOSE RIVETS CAUSED PROBLEM lol!!!!! 3:16 (yammie tony)
HEY , I BET THAT WATER SKIPING MADE THAT DCS LITE UP !! WONDER IF IT WOULD STAY ON IF YA SANK!!!!
 
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mine goes off I guess because the rivets are loose on my rear flap...LOL.I jetted up to 01 specs and the light was hardly coming on.Left the pilots ar 42.5,is that still ok or should I go to 40's YAMMIEGOD3:16..My fuel screws at 1.5 turns.Noticed maybe sled is rich at idle,hesitates or bogs when pinned.That is on warm days mind you.Maybe my floats are off,seems to load up with fuel maybe.Had wrong plugs in sled to,maybe that didn't help.
 
PILOTS CONTROL IDLE. SO IF YOU THINK ITS RICH !! LOOK, AGAIN, 01 SRX SPEC,s OR UP OCTANE WHICH REQUIRES RACE FUEL. MOST WON,T DO LATTER SO JUST KEEP INCREASEING JETS SIZE ACROSS THE BOARD UNTIL LITE STAYS OFF. LET ME SUGGEST A 2002 YAMAHA TECH MANUAL. GIVES YA COMPLETE FUNCTION OF THIS SYSTEM AND SRX JETTING CHART. I DON,T KNOW WHAT TOO TELL YA. !!! 3:16 (yammie tony)
 
Your clutching affects the RPM range in which the sled operates at a certain throttle position. The DCS is sensing detonation which is only caused by 2 things and 2 things only and that's either lack of fuel (lean) or fuel that is too low on octane!
 
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