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New 525sx help

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I just bought a new leftover '03 525sx. After riding a late 90's RM 250 for the last several years, all I can say is - What a machine! I would like some feedback on two items. I adjusted the jetting to a 45 pilot, raised the needle one notch, airscrew at 1 3/4 out. It seems to run better than with the leaner stock jetting, but it is harder to start. Stock jetting, I could kick it 1-3 times hot or cold and it would start. Now, when cold, it starts fine. When hot, it basically will not start without the hot start and usually takes 4-8 kicks with it. I'm taking my hand off the throttle to make sure I'm not turning it. Any help? Also, any feedback on gearing for general moto use. I find myself wanting something between 1st and 2nd gear for tight corners on a motocross track. And also wouldn't mind being able to putt around on a trail with my kids on ocassion. Is 14/50 reasonable. I do not want to shorten the gears too much, but would like to get out of using 1st on most tracks. I've had a false neutral or two already. Thanks,

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Congratulations, and welcome to the Orange side :cry:

The JD jetting kit is very popular on these bikes. Really it is the needles that are the key, but they come with pretty bang on suggestions on settings. Really woke up my EXC, and I ended up with better mileage, too.

Can't really help with the gearing, as the EXC has dramatically different gears. "Putting" on a motocross geared bike with a light flywheel will be a challenge. One thing you may want to look into eventually is adding the extra two gears to make it a six speed. Not that expensive (the gears are actually already there), and it would allow you more flexibility on gearing.

Good luck and enjoy

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First try setting the fuel screw back to 1 turn out if that doesn't work put the stock pilot back in and shorten the accelerator squirt time to 1 sec. The reason your bike is hard to start is because when you installed the bigger pilot you richened the circuit to much. You in effect are trying to start the bike with the choke on. four strokes when cold like a slightly richer fuel mixture but when they are hot they like a leaner mixture to start (I.E. hot start)

Also remember on a 4 stroke the screw you are adjusting is a fuel screw NOT an air screw. When you close the screw you are leaning the mixture out and the farther out you go the richer you make the mixture - it does the opposite of a 2 stroke.

A 14:50 or 14:51 will make the bike about perfect for mx and light trail riding. I personally run a 14:51 and have never found a track where I'm running tapped in 4th.

Noregg is almost correct. You can install a 6 speed but only 2 of the 4 gears needed are in the bike. Parts cost is about $300. I've done this to all my bikes (and over 100 others). It makes the bike way more versatile.

Last the '03's have a very light crank (40 oz over previous years) which makes them a little harder to start and easier to stall because of the lower crank inertia. KTM added 28 oz to the cranks for '04 for this very reason. There are crank weights avalible.

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Thanks for the help. I will go in with the fuel screw to lean it a bit. If that doesn't work out, I'll consider going back to the 42 pilot. Not familiar with the accelerator squirt time. I'll look in the book on that one.

I haven't had a hard time with stalling it yet, but learned to use the back brake almost not at all in order to keep the back wheel rolling coming to corners. The downshifting seems to give me all the back brake I need.

I will swap to 14/50 gearing when I replace the chain and sprocket. I hope the stock chain gets better than the hourly adjustment it has needed so far. Thanks for the help

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Thanks for the help. I will go in with the fuel screw to lean it a bit. If that doesn't work out, I'll consider going back to the 42 pilot. Not familiar with the accelerator squirt time. I'll look in the book on that one.

I haven't had a hard time with stalling it yet, but learned to use the back brake almost not at all in order to keep the back wheel rolling coming to corners. The downshifting seems to give me all the back brake I need.

I will swap to 14/50 gearing when I replace the chain and sprocket. I hope the stock chain gets better than the hourly adjustment it has needed so far. Thanks for the help

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For me, I followed a KTM bulletin for hard hot-starting...

They basically recommended lowering the needle back down.

(I have the bulletin at home so that 's all I can offer)

I've had no problems since and haven't noticed any changes in power...(love this bike!)

One other thing...I put the EXC flywheel and stator in my SX/SMC (to power lights) and THAT made a HUGE difference in slow/tight rideability. (never stalls now, even with the same gearing as before)

I did lose a little of the ultra-quick revving, but, honestly don't miss it.

Still waiting to get the 6 spd installed...

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If you are going to do a lot of woods riding, consider the 13/52 combo (first is really high), once jetted right you should be able to fire that thing up first or second kick (I never have an issue with re-starting). Also a rev-loc will make that thing an ultimate off road bike especially with a bit lower gearing and that 5th and 6th in it (helps starting and kills stalling), although you may find it gets in the way on the track a bit.

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Also, I run a 45, with a more tapered needle. seems to be good all year long with a few turns on the carb screw.(hot summer and cool winter).

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Not sure the difference in fly wheel weight between my EXC and your SX, but I can lug mine down to like 5mph for a short while in 3rd.

You can either try adding a little FWW (mabye 6oz or something?)

I have the same problem with my YZ450F, that's why I got the 525EXC with 6 gears.

I guess another option for you is to talk to Travis about a 6spd kit, then gear it down some so you still have top end.

Cheers,

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BTW...I was running 14/42 gearing w/the SX flywheel + being in Supermoto trim (17" wheels)when I was stalling in the dirt section of the track. (oh and the bike was new to me as well) :cry:

Now, with the EXC flywheel (and granted) being more familiar with the bike...I'm having no problems.

(still 14/42 :cry:)

Also, following the KTM bulletin on jetting, hot-restarts are a 1 or 2 kick piece-o-cake :cry:

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