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Idle trouble after 1 min run time 525EXC rfs

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Ok, I've been thru the ringer with idle issues but here's where is stands. '07 525 EXC starts right up cold, use a little choke if needed, kick the choke off and it idles and revs fine. After about 1 min is dies. It will restart, but won't idle well and dies. If I get it up on the main jet it rips up the road, but close the throttle and it pukes.

I've been thru the carb several times, I am confident that between new parts and cleaning I just don't see how that's the issue particularly when is runs well on first start up.

I just rechecked valves, all spot on

New spark plug

Cleaned entire fuel system

new pilot jet, cleared all carb passages, proved all vents, new hoses are dangling

It seems to maybe be heat related?? If I start it up tomorrow I believe it will do the exact same thing again.

What could kick in after a minute?

Ignition module, throttle position sensor, do the electronics change anything after it senses warm, does it even sense warm?

...frustrated I'd appreciate all help.

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How are you venting the gas tank? Some folks have had problems with those shorty 1-way valves. Not necessarily heat related, but time related.

Good luck,

MrHix

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Stock cap with checkvalve removed and hose vented to the frame port on the right side

Also, it started suddenly - worked great then didn't...

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Stock cap with checkvalve removed and hose vented to the frame port on the right side

Also, it started suddenly - worked great then didn't...

Sounds like to me its starving for gas or air.thats why it runs for awhile than it runs out of gas or air.Try taking the gas cap all the way off when its messing up.If that dont work go thru the carb again blowing out all the lines,doesnt take much to have a blockage some where.

Edited by ktm450guy

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Spark plug cap again... matches the description 100%. Once it gets hot it just stops conducting. You should find a replacement from any automotive store or just use a spark plug cable with integrated cap without resistor.

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I did trim a 1/4 inch off the plug wire and reset the cap, test with gas cap off, No go. I did confirm today it still runs like a beast up off idle.

The passage after the pilot that splits and goes to the first hole, and also by the mixture needle is suspicious. I did blow thru all those and confirm clear, but are they fully clear? What techniques can be used to clean better? Has anyone ever taken off the torx visible in the top of the float chamber - does that offer better access to that passage? What gasket in there? The parts blow up, eve at Sudco doesn't even show that it comes apart there and no gasket appears to be available. ??

I can probably dig up an old plug cap to use as a test... but it tears up the road up off idle which tells me it's probably sparking OK.

Thanks

Edited by trooper8

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Just try it, it acts very wierd. I tried chasing a mysterious carb problem for way too long because I thought there was no way it could be spark related until I tried a new spark plug cap :bonk:

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My new best friend from Finland nailed it!

I rigged in an old plug wire from a 1994 Ford Explorer and it ran like a dream, sat there idling until the fan kicked on and kept going! Many Thanks to by TT buds! I look forward to returning the favor sometime.:bonk:

Just try it, it acts very wierd. I tried chasing a mysterious carb problem for way too long because I thought there was no way it could be spark related until I tried a new spark plug cap :smirk:

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I learned something here,i thought it would have for sure been the carb.But than again i never had the plug wire prob.Never to old to learn something new.

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The real trick was determining it was/wasn't carb. I used starting fluid to try to keep it running while it was acting up. A shot of ether would instantly kill it, not support it like it would if it was not getting fuel.

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