snowdemonsrx
New member
Hello everyone, I bought a used 02 SRX a couple years ago and last December 07 there was enough snow to ride before christmas major shock here in lower Michigan, anyway the sled wasn't running right the DCS light kept flashing, I put fresh premuim gas and new plugs in also seaform fuel system cleaner in the tank, did a plug check to check jetting and the plugs were nice and brown like normal but the sled was lacking top speed, one night the temp light started flashing so I just went back to the hotel and parked it for the night, the next morning the sled ran great no lights came on at all and I ran the hack of it 110 + mph I figured that the fuel system cleaner must of worked I rode the side of the road for a bit slow and got to a nice unplowed road and went to get back on it and it wouldn't go over 90 and started back firing so I stopped and checked the plugs I melted the far right piston!
I got home and took it a part and only the right piston and cylinder was destoryed, the other 2 were fine, So I replaced everything with OEM yahama parts to keep everything the same shock and cleaned the carbs and found that only the pilot jets were clogged not the mains, so I cleaned both mains and pilots jets twice in all carbs and but it back together and it started right up so I decide to clean the other two power valves and there both broken pulled out of the cables, but not the cylinder I just replaced, So now I have to replace the power valves and I seen on this forum how to adjust them now thank you, My question to all is before I go up riding this $850.00 repair what should I look for check out so this doesn't happen again does this happen often on SRX's to melt a piston ?
P.S the sled is all shock with 4000 miles
Thank you
I got home and took it a part and only the right piston and cylinder was destoryed, the other 2 were fine, So I replaced everything with OEM yahama parts to keep everything the same shock and cleaned the carbs and found that only the pilot jets were clogged not the mains, so I cleaned both mains and pilots jets twice in all carbs and but it back together and it started right up so I decide to clean the other two power valves and there both broken pulled out of the cables, but not the cylinder I just replaced, So now I have to replace the power valves and I seen on this forum how to adjust them now thank you, My question to all is before I go up riding this $850.00 repair what should I look for check out so this doesn't happen again does this happen often on SRX's to melt a piston ?
P.S the sled is all shock with 4000 miles
Thank you
Last edited:
valin
Active member
Does what happen often on SRX's? The valves? Yes, if you don't stay on top of things and keep them clean. They are a pain in the ***, but do work well. Take them apart and clean them every 500 miles, and they will last quite a while.
Drain your tank, get rid of that damn seafoam, and start over with fresh fuel.
Drain your tank, get rid of that damn seafoam, and start over with fresh fuel.
Burn down was most likely from the carbs not being cleaned. You need to clean them every year!
daman
New member
Are you running '01 jetting??? are you using BR9ECS plugs????
must must use good premium fuel the highest you can find.
must must use good premium fuel the highest you can find.
Well if the pilot jets were plugged as you say right theres your problem, all fuel circuits overlap, so your low speed/mid speed cruising circuit would have been lean, the pilot jet also plays about 2-3% of total fuel flow even at WOT.
If any of the circuits are clogged it will effect the next in line circuit because of the overlap, it is almost always the mid range in which an engine will burn down, because this is simply the amount of throttle most used and it also is the leanest portion of the fuel curve, its when you let off the gas after a wot run that it gets very lean, the needle drops into the main and shuts the fuel flow off instantly and the pilot and needle circuit have to provide the fuel at that instant to an engine turning high rpm still, rapid intake of air but a smaller fuel curve from the pilot/needle circuit. Clogged pilot jet, you were lean right there. Clean the carbs every year and you wont have any problems any more.
If any of the circuits are clogged it will effect the next in line circuit because of the overlap, it is almost always the mid range in which an engine will burn down, because this is simply the amount of throttle most used and it also is the leanest portion of the fuel curve, its when you let off the gas after a wot run that it gets very lean, the needle drops into the main and shuts the fuel flow off instantly and the pilot and needle circuit have to provide the fuel at that instant to an engine turning high rpm still, rapid intake of air but a smaller fuel curve from the pilot/needle circuit. Clogged pilot jet, you were lean right there. Clean the carbs every year and you wont have any problems any more.
blueblood
New member
Valin I was curious by the "damn seafoam" comment. I've herd others on the site praise it. Have you had bad experiences with it?
cacsrx1
New member
blueblood said:
I use it all the time, keeps the valves nice and clean.
Yamahasrx700
Member
Yamahasrx700
Member
If you buy new valves I will take the bad ones off your hands
ExpertXViper
New member
cacsrx1 said:
Your carbs too.....Stuff can be used for countless things including engine fogging and carb stabilizer, 2 things that should done at the end of every season. Burn down was diff. not caused by sea foam.
snowdemonsrx
New member
Thanks for the info, I did some checking online and here what I found
#1 Industry-leading electronic power valves for increased engine performance. The self-cleaning feature maintains optimum performance.
>>>>>How do they clean themself ? also I use the high dollar oil Amsoil intercepter both seem to fail here!
#2 The new DCS keeps this unrelenting performance in check by monitoring the combustion process and moving into a fail-safe ignition retard zone when the potential for power robbing engine detonation is present. Go ahead, let the SRX engine scream the performance note it was intended and leave the worries of bad fuel and irregular jetting to advanced Yamaha technology
>>>>>The DCS light was working and I got off the gas everytime it came on
So if it retarded the timing adding more fuel to richen the air / fuel mixture
how did it burn up ?
I don't mean to bash yamaha or anything but I don't understand the fail safe and cleaning features not working
Also can I just replace the power valves or do I need to replace the cables as well, I don't see anything wrong with the cables?
Thanks again
#1 Industry-leading electronic power valves for increased engine performance. The self-cleaning feature maintains optimum performance.
>>>>>How do they clean themself ? also I use the high dollar oil Amsoil intercepter both seem to fail here!
#2 The new DCS keeps this unrelenting performance in check by monitoring the combustion process and moving into a fail-safe ignition retard zone when the potential for power robbing engine detonation is present. Go ahead, let the SRX engine scream the performance note it was intended and leave the worries of bad fuel and irregular jetting to advanced Yamaha technology
>>>>>The DCS light was working and I got off the gas everytime it came on
So if it retarded the timing adding more fuel to richen the air / fuel mixture
how did it burn up ?
I don't mean to bash yamaha or anything but I don't understand the fail safe and cleaning features not working
Also can I just replace the power valves or do I need to replace the cables as well, I don't see anything wrong with the cables?
Thanks again
daman
New member
All Yamaha's self cleaning is every time you start the engine the sevosnowdemonsrx said:
cycls the P/V's open/closed to keep any build up scraped off.
and yes running a good full syn. will help but NOT cure pv's sticking!!!!
they still need service once or twice a season depending on milage.
DCS can only retard timing so much,it's not a miracle cure,but does help alot, you can still be detonating with the DCS activating, if on the trigger.snowdemonsrx said:
yes the valves can be replaced only, do a search some members have fixedsnowdemonsrx said:
there own instead of buying new,maybe they could help you..
Skidooslayer687
Member
i fixed one of my valves at work, only took 20 minutes or so, lot better then droppin $100 into one of them
>>>>>The DCS light was working and I got off the gas everytime it came on
So if it retarded the timing adding more fuel to richen the air / fuel mixture
how did it burn up ?
because once the timing was retarded you still had no fuel coming in with plugged up pilot jets! the dcs cant keep anything from happening its just a tool, if used right works good but it cant save the engine when the jets are plugged up and you keep riding the sled, there would have been signs the carbs were dirty, it wouldnt have idled on its own without the choke being applied, it would have stumbled upon take off till about half throttle.
Theres no reason to cry now over spilled milk, but you can avoid this whole incident next time by simply cleaning the carbs each year and running fresh fuel each year first tank out.
So if it retarded the timing adding more fuel to richen the air / fuel mixture
how did it burn up ?
because once the timing was retarded you still had no fuel coming in with plugged up pilot jets! the dcs cant keep anything from happening its just a tool, if used right works good but it cant save the engine when the jets are plugged up and you keep riding the sled, there would have been signs the carbs were dirty, it wouldnt have idled on its own without the choke being applied, it would have stumbled upon take off till about half throttle.
Theres no reason to cry now over spilled milk, but you can avoid this whole incident next time by simply cleaning the carbs each year and running fresh fuel each year first tank out.
snowdemonsrx
New member
I'm wasn't crying, I spent a lot of money fixing this and I wanted to cover all my bases so this doesn't happen again! I was only picking your brains to see if there was something I over looked in the rebuild!
Thanks
Thanks
thats merely a metaphore, I didnt mean it as you were whining. meaning damage already done hard lesson learned I am sure! Youll be fine if the carbs are clean now. 