2002 SRX DCS Experiences

sideshowBob

sideshowBob

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Location
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Sorry about the length of this post but I feel all the info is required to get my point across and hopefully it will help someone else.

I have been riding, racing, repairing, tuning + modifying, sleds for well over 40 years,[cars, aircraft, bikes+ boats as well, mostly all for personal hobbies + my first orginized race I entered was in 1965 on my Dad's Snow Cruiiser!] The more I learn the more I realize how little I know!

I have read every DCS post in this forum with interest and to gain insight into dealing with this issue on my own sled.

My SRX has had DCS issues since aquiring my Like New , Low Mileage , 2002 SRX a few years back.

Any time I did a long pull or drag race I would get the DCS flash and subsequent performance loss, the sled was like this when it was completely stock. This sled also was what I would call "slow" for what it was.

Porting, reeds, Aaen pipes, heads, clutching, boost bottle,airbox mods, cold air kit ect ect, just added to the problem.

To counter act the problem, I tried numerous things including the following[even when it was stock]:
-checked/cleaned power valves
-checked motor mounts
-I always ran premium fuel blended with 100 LL av gas
-jetted the sled "pig rich"
-tried different head configurations[I have 3 sets of Yamaha heads plus Peak heads with numerous different inserts]
-checked crankshaft phaze/indexing
-ect ect

I had only limited success with every attempt I made to keep the DCS out, but any time the sled would start to make power it would flash the DCS!!!.
Finally I wired in a selector switch with one end to a vibration insulated "dummy" DCS sensor with the other position to the stock mounted DCS sensor and selected between them depending on what I was doing, racing or just riding.

This past summer I removed and installed an engine I had totally rebuilt and included all of the following:
-NEW indexed Viper crankshaft
-ported cylinders
-ported cases
-swain tech coated Stock pistons, new rings, pins + bearings
-NEW stator
-power valves with stainless ends by YA*MA*HEAD
-elliminated boost bottle[as per Valins info]
-got rid of the VForce IIIs + installed Boyeson Rage cages
-added reed spacers
-ect ect

I now have the sled broken in with at least 300 miles on it and have ZERO DCS issues!!!!
LOL ! Yes it is working!
I have jetted the sled down from 157.5s[vents out of box] to 155s[vents in the box] and been running in temps as cold as at -30C/-24F and even when doing a long wide open lake crossing I have not had a single DCS flash!!! All on 91 octane Shell VPower fuel!

The sled has NEVER run so strong, it now pulls like a freight train and Yesterday, on the GPS, ran 107mph/173kph on the hard pack, this is with a high venture windshield, 3" bar rise, hand gaurds, 144"x 1 1/4" ripsaw, boss high rise flat top seat, long travel suspension![obviously not set up for speed!] Its running so well I removed the"Dummy" DCS sensor.

Now to my point! lol ! finally!

I feel due to the age of these sleds the DCS is starting to give problems that are a result of either mechanical problems +/or mechanical wear.

In regards to my 2002 SRX, when I installed the rebuilt engine I also ,fortunately, corrected the DCS issue that this sled was basically suffering from since it was new:
-poor stator output[my hand warmers are operating WAY!!! better since the new stator]
-crankshaft issues...this is what I think was the real problem with this sled. I believe the crank was either out of balance +/or phaze[even though it looked good on a degree wheel] or some other bearing issues that disturbed the engine harmonics.

JM.02c


Hope this helps!
 
Last edited:

2002 Srx Dcs

Curious... any input as to why you switched to a "VIPER" crank rather than rebuilding/trueing/welding your SRX crank??? I'm not positive but I believe the 2 cranks are different in design... Viper=pork chop design=lighter/quicker revving??? Just this past weekend, riding my '02 SRX was the FIRST time I've seen the DCS active over a complete,long,wide open run... I'm thinking this was due to suspect (old) gas as I had to fill up at remote gas station.GREAT POST!
 
northern srx said:
Curious... any input as to why you switched to a "VIPER" crank rather than rebuilding/trueing/welding your SRX crank??? I'm not positive but I believe the 2 cranks are different in design... Viper=pork chop design=lighter/quicker revving??? Just this past weekend, riding my '02 SRX was the FIRST time I've seen the DCS active over a complete,long,wide open run... I'm thinking this was due to suspect (old) gas as I had to fill up at remote gas station.GREAT POST!
Click to expand...

I always suspected the crank on my SRX. I stumbled across the new Viper crank for a great price while ago and thought I would try it because of the lighter pork chop design, also it accomplishes the same principle as cutting vanes in the crank would[although I think the perf gains from that is imaginary]
I also aquired a set of cases + sent the new crank out to be checked for straighteness and phaze...it needed to be straightened some but the phaze was good. When I pulled the motor this summer I basically just installed a complete already assembled engine, my old engine is now sitting still assembled on the work bench.
 
Last edited:
SRXSRULE2 said:
I'll almost guarantee all your former DCS problems were from running the 100 octane fuel blend. What were you mixing it to??
Click to expand...

The sled flashed the DCS on any fuel that I used including VP Race Fuel[C12] that I had for my VMAX4 MOD sled.
When I use AV gas in my 2 strokes[only when Comp ratio requires] the 100LL/Premium pump fuel blend I use is a MAX of 3 parts premium pump fuel to 2 parts 100 LL Av Gas which works out approx 94 octane.
My DCS issues were definately mechanical +/or electrical in nature and present right from the get go.
 
Last edited:
The DCS light will flash on my Dad's 02 SRX if you run say 87 octane as well if you run 94. Quit running sunoco 94 because of it. Asked the dealer about it, he states they run to hot on 94.. stated about a stock sled. Your problem could of been mechanical, but I know the fuel caused ours. At least you fixed your problem. Its a good system, can be a pain in the @$$ at times.
 
sideshowBob said:
Sorry about the length of this post but I feel all the info is required to get my point across and hopefully it will help someone else.

I have been riding, racing, repairing, tuning + modifying, sleds for well over 40 years,[cars, aircraft, bikes+ boats as well, mostly all for personal hobbies + my first orginized race I entered was in 1965 on my Dad's Snow Cruiiser!] The more I learn the more I realize how little I know!

I have read every DCS post in this forum with interest and to gain insight into dealing with this issue on my own sled.

My SRX has had DCS issues since aquiring my Like New , Low Mileage , 2002 SRX a few years back.

Any time I did a long pull or drag race I would get the DCS flash and subsequent performance loss, the sled was like this when it was completely stock. This sled also was what I would call "slow" for what it was.

Porting, reeds, Aaen pipes, heads, clutching, boost bottle,airbox mods, cold air kit ect ect, just added to the problem.

To counter act the problem, I tried numerous things including the following[even when it was stock]:
-checked/cleaned power valves
-checked motor mounts
-I always ran premium fuel blended with 100 LL av gas
-jetted the sled "pig rich"
-tried different head configurations[I have 3 sets of Yamaha heads plus Peak heads with numerous different inserts]
-checked crankshaft phaze/indexing
-ect ect

I had only limited success with every attempt I made to keep the DCS out, but any time the sled would start to make power it would flash the DCS!!!.
Finally I wired in a selector switch with one end to a vibration insulated "dummy" DCS sensor with the other position to the stock mounted DCS sensor and selected between them depending on what I was doing, racing or just riding.

This past summer I removed and installed an engine I had totally rebuilt and included all of the following:
-NEW indexed Viper crankshaft
-ported cylinders
-ported cases
-swain tech coated Stock pistons, new rings, pins + bearings
-NEW stator
-power valves with stainless ends by YA*MA*HEAD
-elliminated boost bottle[as per Valins info]
-got rid of the VForce IIIs + installed Boyeson Rage cages
-added reed spacers
-ect ect

I now have the sled broken in with at least 300 miles on it and have ZERO DCS issues!!!!
LOL ! Yes it is working!
I have jetted the sled down from 157.5s[vents out of box] to 155s[vents in the box] and been running in temps as cold as at -30C/-24F and even when doing a long wide open lake crossing I have not had a single DCS flash!!! All on 91 octane Shell VPower fuel!

The sled has NEVER run so strong, it now pulls like a freight train and Yesterday, on the GPS, ran 107mph/173kph on the hard pack, this is with a high venture windshield, 3" bar rise, hand gaurds, 144"x 1 1/4" ripsaw, boss high rise flat top seat, long travel suspension![obviously not set up for speed!] Its running so well I removed the"Dummy" DCS sensor.

Now to my point! lol ! finally!

I feel due to the age of these sleds the DCS is starting to give problems that are a result of either mechanical problems +/or mechanical wear.

In regards to my 2002 SRX, when I installed the rebuilt engine I also ,fortunately, corrected the DCS issue that this sled was basically suffering from since it was new:
-poor stator output[my hand warmers are operating WAY!!! better since the new stator]
Click to expand...
-crankshaft issues...this is what I think was the real problem with this sled. I believe the crank was either out of balance +/or phaze[even though it looked good on a degree wheel] or some other bearing issues that disturbed the engine harmonics.

JM.02c


Hope this helps!
Click to expand...

Is it possible your weak stator was the problem all along?
 
unchained said:
Is it possible your weak stator was the problem all along?
Click to expand...

I was always suspect of the stator and/or the crankshaft as the reasons my sled underperformed and had DCS issues[I also had tried a different CDI with no luck]. That is why both were changed during the rebuild.

I never new how poorly my hand grips were working until I installed the new stator! The warmers were working about as good as all of my other Yamahas and now that the stator has been changed I can hardly ever run them in the full hot position, even at -30C !

Again I have to say...this sled is now a "Rocket" compared to what it was and finally hammers our ported/piped 700SX.

The reason I bought the 2002 was for its DCS and I rode the sled the way it was for over 6000miles...I wish I would have figured it out earlier!!!

I plan on taking the original crankshaft to my "Crank Guy Les" in the summer so I will eventually find out if the crank was a problem later on, but I am really starting to think it was the stator.

If you check the stator part numbers for the 2000 - 2002 SRX...Yamaha has updated the stator to the same number as the newer Vipers...Things that make you go Hmmmm.
 
Great posts guys!

I finally got out riding the other day and barely ever see the dcs come on. I filled with Ultra 94(Sunoco) and I had slight DCS flashes on the way home but not doing a wide open run. I was doing 100km/hr down the trail at a steady cruising throttle. The theory about Ultra 94 running hotter possibly may be my issue.

WHat do u guys think??? thanks
 
sideshowBob said:
I was always suspect of the stator and/or the crankshaft as the reasons my sled underperformed and had DCS issues[I also had tried a different CDI with no luck]. That is why both were changed during the rebuild.

I never new how poorly my hand grips were working until I installed the new stator! The warmers were working about as good as all of my other Yamahas and now that the stator has been changed I can hardly ever run them in the full hot position, even at -30C !

Again I have to say...this sled is now a "Rocket" compared to what it was and finally hammers our ported/piped 700SX.

The reason I bought the 2002 was for its DCS and I rode the sled the way it was for over 6000miles...I wish I would have figured it out earlier!!!

I plan on taking the original crankshaft to my "Crank Guy Les" in the summer so I will eventually find out if the crank was a problem later on, but I am really starting to think it was the stator.

If you check the stator part numbers for the 2000 - 2002 SRX...Yamaha has updated the stator to the same number as the newer Vipers...Things that make you go Hmmmm
Click to expand...
.
Click to expand...
I agree, thats interesting.
My handwarmers are dead right now so Im on the prowl to figure it out. Left the sled at the cabin so i'll have to take the multi meter up with me and start narrowing things down when I get up back up this weekend. I was confident I would find the grips were shot or the variable resistor but now after doing searches on here I see it could be the cdi or even the stator.
 
chris189 said:
Great posts guys!

I finally got out riding the other day and barely ever see the dcs come on. I filled with Ultra 94(Sunoco) and I had slight DCS flashes on the way home but not doing a wide open run. I was doing 100km/hr down the trail at a steady cruising throttle. The theory about Ultra 94 running hotter possibly may be my issue.

WHat do u guys think??? thanks
Click to expand...
My DCS will sometimes flash when Im just cruising as well. Just a blip of the throttle and its back off. Awesome technology!
 
THIS IS A GREAT POST FOR 2002 SRX OWNERS. GREAT JOB BOB. I BOUGHT MY 2002 SRX BRAND NEW IN THE BOX IN 2004. IT WAS LEFTOVER AND CRAZY ENOUGH, JUST DID NOT SELL. MY LONG TIME DEALER RETIRED THAT YEAR SO I GRABED IT. UNLIKE YOURS, MY 2002 SRX FLEW, NEVER EVER STOPED PULLING TOP END. I WOULD HAVE SLIGHT DCS ISSUE RIGHT AT END OF LONG PULLS WITH SUNOCO ULTA 93. TALKED TO ONE OF THE BEST YAMAHA GUYS I KNOW WHO WAS AT THIS DEALERSHIP SINCE EARLY SEVENTIES, AND HE TOLD ME STEP UP OCTANE, OR RUN 01 JETTING SPEC. THAT SIMPLE. WELL I WAS ABLE TO FIND NATURAL 100 OCTANE FUEL. I ALSO TRYED 110 RACE FUEL MIXED WITH 89. DCS LITE HAS NOT BEEN ON IN 5 YEARS. 3:16 (yammie tony)
 
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