Took my 2000 srx 700 0ff the trailer to do some testing for the upcoming radar run. She started like a pos and my back is still sore from pulling it over. Got it going but noticed right away she was not running right like a cylinder was down. I let it warm up and took it for a quick rip around the pond and knew something was wrong. Pulled the plugs pto and center cylinder plugs were brown but mag cylinder was soaked with fuel. Replaced plug, and started again same result, and pipe was not getting hot like the other pipes. I checked spark and had spark on all cylinders. Not sure what was wrong I just loaded it back on the trailer. I am going to purchase a compression tester and check compression, and maybe replace coil pack as I was thinking maybe it is cutting out under load. Not really sure any suggestions would be helpful. Radar run is 2/17/18 and I would like to make it, as I only use this sled for grass drags and radar runs!!
Thanks
Derek
Thanks
Derek
A couple of bucks
VIP Member
That problem cylinder has a seal issue on the carb. It sounds like the cylinders carb was sifoning during the trip over to where you were testing. That’s why she didn’t want to start.
Just spitballing.
Just spitballing.
Mac
Member
Another thing to check out. Fuel pump. I don't have an SRX any longer. Question for the group? What cylinder does the impulse line connect too. I remember when my fuel pump failed it drowns the cylinder with fuel. No fire in that cylinder at all.
Another thing to check out. Fuel pump. I don't have an SRX any longer. Question for the group? What cylinder does the impulse line connect too. I remember when my fuel pump failed it drowns the cylinder with fuel. No fire in that cylinder at all.
Hmm
The last time I ran it at the radar runs in Rangely Me It started really hard that day as well, and didn't perform as well as I wanted it too. I wonder if the fuel pump is weak. The sled has 2060 Miles.
Mac
Member
These are diaphragm pumps that run off an impulse line connected to a nipple on the crankcase. Depending on the failure the impulse can pull fuel back and drown that cylinder. Swap the pump. I think its your turn to be lucky Derek.
---mac---
---mac---
mrviper700
VIP Lifetime Member
the fuel pump is pulsed by the center cylinder not the mag cylinder. More then likely you have a leaky needle and seat in the carb allowing excess fuel to leak into cylinder while trailering it. sometimes you can clean up the seat with twisting a drill bit in the hole gently and then using wet/dry paper clean up tip of needle.
the fuel pump is pulsed by the center cylinder not the mag cylinder. More then likely you have a leaky needle and seat in the carb allowing excess fuel to leak into cylinder while trailering it. sometimes you can clean up the seat with twisting a drill bit in the hole gently and then using wet/dry paper clean up tip of needle.
So would that cause the cylinder to continue to not run properly even after you swap the plug out?
Thanks
RXMax
Member
Yes if a bad needle and seat is over fueling that cylinder. Even with spark, too much fuel will not build heat and not run correctly.
mrviper700
VIP Lifetime Member
if its puddled gas in the case and in the pipe, its hard to get it going(running on that cylinder) as the gas is brought back into the cylinder by the pipe charge, so yes, it will still run/ not fire on the cylinder if its flooded.
I would pull the carb rack and go over them, also check to make sure the choke plunger returns all the way closed on that cylinder.
I would pull the carb rack and go over them, also check to make sure the choke plunger returns all the way closed on that cylinder.
I will do that and report back.
Thanks for the help guys
Thanks for the help guys
Got my needle and seat out and it seemed pretty good except the o ring seems pretty worn. I can imagine that woould let fuel seep by when sitting. How do I determine the size of these and where can I get new ones? Figured I would replace them for piece of mind. I really would like to give the 660 radar run another go this weekend since I got the recommended helix and secondary spring!!
Thanks guys
Thanks guys
RXMax
Member
MY local Yamaha dealer stocks them!
did you pressure check your needle valves?
did you pressure check your needle valves?
MY local Yamaha dealer stocks them!
did you pressure check your needle valves?
I did not. I would not know how to go about that!
I ordered 3 new needle and seat kits, will have by Thursday will let you know if it cures her! If I amvdoing all 3 will I still need to make carburator adjustments?
RXMax
Member
Good call! I was going to suggest that!
Put them in and make everything is to stock spec for mixture screw, needle height and float level.
Put them in and make everything is to stock spec for mixture screw, needle height and float level.
mrviper700
VIP Lifetime Member
the crappy ethanol used in gas these days breaks down the rubber carb parts over time. I have seen more and more O-rings and fuel lines, etc getting hard and brittle and need replaced. These sleds are now getting old as well.... 2000 srx is now 18yrs old...lol, so its not really a surprise these items will need changed.
I never adjusted anything on my carbs except jetting and air fuel screw. They aren't cheap $116! A few hundred more I could have got mr viper to trail port her!!
Thanks Guys
Thanks Guys
ethanol is terrible! I found some non ethanol gas stations and have been using that now that she don't see trails anymore.
captnviper
Lifetime Member
I did a little clicking around, I believe these are the ones you would need. https://www.amazon.com/gp/offer-listing/B00CQ7XN7M/ref=dp_olp_new_mbc?ie=UTF8&condition=new which is way cheaper. https://www.jetsrus.com/individual_parts/002_900_su.html Even these mikuni ones are cheaper
Thanks I appreciate you looking around. I already ordered them and did over night shipping so I would get them and be ready Saturday for the radad runs! My price included new screens as well. I will follow up Friday with the results of the new needle and seat kits.