KTM 525 sx
- Thread starter mfatty
- Start date
I have a 04 EXC 525. Great engine very reliable. Not sure how the close ratio tranny works. but a lot of guy like that tranny.
E
2003 525 SX
The close ratio tranny is much better for the snowbike application. I have ridden a 2003 525sx for about 4 seasons and a friend had a 2005 540 (big bore) exc and they were pretty close, what closed the displacement gap was the close ratio. He actually swapped to the close ratio when rebuilding the engine. The 525 works great, the kick only kind of stinks, but you will have one tough right leg by spring. The major issue I had was carb ice just like every other bike on the snow. You'll be happy with the 525 until you ride a 500 2-stroke.
The close ratio tranny is much better for the snowbike application. I have ridden a 2003 525sx for about 4 seasons and a friend had a 2005 540 (big bore) exc and they were pretty close, what closed the displacement gap was the close ratio. He actually swapped to the close ratio when rebuilding the engine. The 525 works great, the kick only kind of stinks, but you will have one tough right leg by spring. The major issue I had was carb ice just like every other bike on the snow. You'll be happy with the 525 until you ride a 500 2-stroke.
is it only a 4 speed? A friend of mine had a 4 speed 520 sx and it would top out at like 40. then we geared it up and you could not get going without smoking the clutch. H ended up swapping in a 6 speed mxc tranny.
cool but just be warned we have steep and deep here and the 4 speed did not cut it. Plenty of power, but it sucks to be topped out at 40.
C
I'm building a 03 and the crank is the weak link so I've been told. It will spread and blow the cases. Welding mine soon to prevent this. Cheaper to weld the to buy all new stuff. Like I said what I've been told and researched it a lot.
R
There is a modification you can do to the 525sx to add 2 more gears. You also want to make sure you have the CDI update which fixes an overrev issue. Do some research on Google and you can find the correct KTM CDI box update number.
J
I have a 05 525 sx absolutely love it lots of rides in the snow. Mine has the six speed conversion and the tall 1st gear is great. I just run with the airbox cover off with the filter skin over the air cleaner have not had one carb ice issue. I added the trail tech stator and electric start. Those parts can be found easy to do such. The big issue i had was overheating on those bluebird spring days. Installed a fan no longer a issue. I am in mine 3k with all the mods just make sure you get a good price up front.
I love my 525exc. Motor is great.Won't rev as high as a 450 but doesn't need to. Valves need adjustment every season, of course, but tough motor.
I am one of the few that prefer the wide ratio tranny (but only on a 500cc bike because they can pull a higher gear from lower rpm. Nice not shifting as much). I use all six gears though first mostly for loading. Mainly use 2 and 3 and a bit of 4 in the deep. 5 and even 6 on the trail for long open runs.
Sx will have much better front fork spring and valving than exc. I'm doing my forks this year to fix the way too soft exc setup. Some even go stiffer than the Sx if you do lots of jumps/drops.
Had carb icing only once but that is very regional (air temp, humidity, etc)
Electric and kick is nice. You can use them at the same time. My 04 is the year ktm experimented with the smaller yuasa battery (ytx4L with 50cca). I changed to the larger battery box of the 05 ktm, but rather than going with that ytx5L with 80cca, I went with the ytz7s with 130cca. Anxious to see how that works this year since it fires the bike instantly now rather than the slow turnover of the stock size battery.
Only other gripe is floodin after a tip over. Best solution is don't tip. Second best is hold open decompression lever for a few kicks to dry it out.
I am one of the few that prefer the wide ratio tranny (but only on a 500cc bike because they can pull a higher gear from lower rpm. Nice not shifting as much). I use all six gears though first mostly for loading. Mainly use 2 and 3 and a bit of 4 in the deep. 5 and even 6 on the trail for long open runs.
Sx will have much better front fork spring and valving than exc. I'm doing my forks this year to fix the way too soft exc setup. Some even go stiffer than the Sx if you do lots of jumps/drops.
Had carb icing only once but that is very regional (air temp, humidity, etc)
Electric and kick is nice. You can use them at the same time. My 04 is the year ktm experimented with the smaller yuasa battery (ytx4L with 50cca). I changed to the larger battery box of the 05 ktm, but rather than going with that ytx5L with 80cca, I went with the ytz7s with 130cca. Anxious to see how that works this year since it fires the bike instantly now rather than the slow turnover of the stock size battery.
Only other gripe is floodin after a tip over. Best solution is don't tip. Second best is hold open decompression lever for a few kicks to dry it out.
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I have the same bike. The YTZ7S fits under the seat? I have the 5 series battery and its a tight fit.
B
As bdoe says, roughly same size and yes it is tight, just like it is with an ytx5L. Once i swapped the '04 battery box for the larger '05 battery box and installed the ytz7s, I chalked the two top corners of the battery and put on the seat so the chalk would indicate where the two made contact. Like many with the 5 series, I lightly dremeled two shallow divots in the bottom of the seat pan and mostly eliminated the contact.
From Yuasa site:
Battery Type: YTX4L-BS
Voltage: 12
Capacity: 3
Dimensions: 4.5" x 2.8125" x 3.375"
Weight: 2.9 lbs.
Metric Dimensions: 114mm x 71mm x 86mm
Metric Weight: 1.3 kg
Acid Volume: 0.18
Amps: 0.4
C.C.A.: 50
Battery Type: YTX5L-BS
Voltage: 12
Capacity: 4
Dimensions: 4.5" x 2.8125" x 4.1875"
Weight: 3.5 lbs.
Metric Dimensions: 114mm x 71mm x 106mm
Metric Weight: 1.6 kg
Acid Volume: 0.24
Amps: 0.5
C.C.A.: 80
Battery Type: YTZ7S
Voltage: 12
Capacity: 6
Dimensions: 4.4375" x 2.75" x 4.125"
Weight: 4.6 lbs.
Metric Dimensions: 113mm x 70mm x 105mm
Metric Weight: 2.1 kg
Polarity:
Acid Volume: N/A
Amps: 0.6
C.C.A.: 130
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mfatty,
Did you get the 525? If so, here is a link to the battery swap that someone wrote up. Worth the swap.
http://www.spokanister.net/ktm_Yuasa_YTZ7S.html
That write up has battery box part number, etc.
Did you get the 525? If so, here is a link to the battery swap that someone wrote up. Worth the swap.
http://www.spokanister.net/ktm_Yuasa_YTZ7S.html
That write up has battery box part number, etc.
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C
Motor
I have fun reading about these toys.
The stock 02 520 will get your appetite whetted I think.
I build the,motors every day and on a strength and power basis I would use completely different later parts in a 565 build.
In other words leave the motor alone or build a completely different fresh motor for the use.
Do run a LEAKDOWN test as the intakes fail making the engibe run hot and the ring/cylinder wears.
I have fun reading about these toys.
The stock 02 520 will get your appetite whetted I think.
I build the,motors every day and on a strength and power basis I would use completely different later parts in a 565 build.
In other words leave the motor alone or build a completely different fresh motor for the use.
Do run a LEAKDOWN test as the intakes fail making the engibe run hot and the ring/cylinder wears.
