srx 700 missing around 7k rpm

Found my problem with 700 sxr cutting out at high rpm's.

Check this out. Pull carbs, pull float and needle and check screen under the needle valve. Small fuel screen bowl type attached to bottom side of needle valve. Mine were all plugged from summer skum build up. This will not allow full fuel flow needed at high RPM or when motor needs it at grunt time.

Thanks for everyone's assistance.
 

Kool...

Kapsuta...sounds like your flooding out during cruise, Id go over those carbs with a fine tooth comb. As I said in earlier post make sure plug boots are good. My SRX600 had rub through under engine, seems they all do.
Try switchin coils if thats what you think, 'talk to the parts' so to say. Two strokes carbs need to be spot on.
 
Adam700sxr said:
Found my problem with 700 sxr cutting out at high rpm's.

Check this out. Pull carbs, pull float and needle and check screen under the needle valve. Small fuel screen bowl type attached to bottom side of needle valve. Mine were all plugged from summer skum build up. This will not allow full fuel flow needed at high RPM or when motor needs it at grunt time.

Thanks for everyone's assistance.
Click to expand...

I'm starting to think that this is my problem.

I was riding today, and missing past 7ish rpm like usual. As the day went on it started missing more and more, at times even below 7k. I was going though a feild and could feel it missing and backfiring pretty bad, and this is when an exhaust pipe blew off - the pto...i put the pipe back on and was on my way. Later, I checked the plugs after doing a 100 yard wot run and killing the engine at about 7k. The mag and center looked fine, but the pto was black as can be and wet. I havent done a comp test yet, but I think the problem was involved with fuel delivery.
 
Hey, i was having the exact same problem with my 98 vmax 700, and iv tried everything also so i started going over the whole wiring harness and like someone else mentioned the ignition wire runs under the motor and i pulled that wire through and mice had chewed down to bare wire so they were probably jumping so i fixed them all up but im not sure if my problems solved because i have no snow but i would check that if you havent all ready since my coils have been fried also . .
 
have you checked to see if you have the proper throttle cable freeplay, i lowered my idle last year to help with idle hang and i ended up with a similar problem because it took out the throttle freeplay, reset the freeplay and problem gone, worth a look
 
Sounds like you have gone through most of the things I would check out... if the plugs are wet after WOT runs then it would lead me to think spark issue... did you try swapping coils around? check the wiring going to the coils... I see you are from Lancaster, what state? I live pretty close to Lancaster NY and could give you a hand diagnosing it.
 
WNYViper said:
Sounds like you have gone through most of the things I would check out... if the plugs are wet after WOT runs then it would lead me to think spark issue... did you try swapping coils around? check the wiring going to the coils... I see you are from Lancaster, what state? I live pretty close to Lancaster NY and could give you a hand diagnosing it.
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Lancaster NY, thats awesome! I didnt try swapping the coils around. I bought a new (used) coil that im gonna change out. I wont really be able to test until there's snow on the ground because like I said it only does it after it warms up for a while, and at high rpm's. But like you said, it either has to be too much gas coming in, or not enough spark. If you're experienced with these I'd love to drive to you and let you look the thing over if I can't get to the bottom of this problem.

(I've built a few 2 stoke engines for my jetskis, but someone with knowledge in sleds would be great)
 
check your reed petals. It could behave like a misfiring problem. My Dad's Viper Venture had that happen. 3 petals were broken. He also had the stator go the year before.
 
mod-it said:
Have you been through the notorious wiring harness that likes to rub through?
Click to expand...

BUMP: still having this problem, I chased it all last winter, and never figured it out.

Is there a normal area for rub through to occur. I looked over the harness and didnt really see anything.
 
Go out and start it up when/where it is nice and dark. Fill a trigger spray bottle w/ water. Bring the RPMs up to where it's missing and start to mist the engine. Shorts will jump from the wires to.....steering column,frame head or whatever easily and make it easy to see.Arcing and sparking. No ya won't get zapped. Done it dozens of times on cars/trucks. Make sure it's DARK though. This should confirm or rule out a short.
 
A couple of bucks said:
Go out and start it up when/where it is nice and dark. Fill a trigger spray bottle w/ water. Bring the RPMs up to where it's missing and start to mist the engine. Shorts will jump from the wires to.....steering column,frame head or whatever easily and make it easy to see.Arcing and sparking. No ya won't get zapped. Done it dozens of times on cars/trucks. Make sure it's DARK though. This should confirm or rule out a short.
Click to expand...

It only seems to miss under load at about 7,000 rpm. I am starting to wonder if it is the stator. If I hold it wide open for an extended period while its misfiring it will sometimes backfire. This leads me to believe I am not burning the gas coming into the cylinder, meaning either the carb is sticking and allowing too much gas to flow in at WOT, or I am losing spark at high rpm's.

I will check near the steering colum for rub through. It runs GREAT until higher rpms.
 
Disconnect any unneed voltage load sources. Lights, grip warmers, etc. Try it and see if the problem is still there. I have seen a similar problem caused by the stator. Sled ran fine without the added load..
 
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