oil leak
- Thread starter jrf4x4
- Start date
I've got an 04 EXC and had the same problem. Apparently this is very common on KTMs.
You cannot flip the sprocket spacer around and reuse it since it has an internal groove cut in one side for an o-ring.
Check the sprocket spacer to see if a groove has worn on the outside of the part where the shaft seal touches it. If it has a very noticable groove, replace the part.
Check the condition of the thin o-ring that is behind the sprocket spacer. This probably needs to be replaced.
Replace the shaft seal if you have not already done so. I made a puller out of a long 1/4 hex head bolt to pull mine out. I ground half the head off of the bolt so that it would fit between the output shaft and catch on the inside of the seal. I then slipped a short heavy piece of steel with a hole drilled in it over the long bolt and then threaded a nut on the very end of the bolt. Use this tool as a slide hammer to remove the seal. Removing the seal this way WILL destroy the seal so have a new seal on hand as a replacement. (Or you can use the correct tool for the job!)
If your countersprocket is an aftermarket part and it thinner than the OEM part it can cause an oil leak. The sprocket/spacer combo has to press tight up against the o-ring mentioned above to make an oil-tight seal.
You cannot flip the sprocket spacer around and reuse it since it has an internal groove cut in one side for an o-ring.
Check the sprocket spacer to see if a groove has worn on the outside of the part where the shaft seal touches it. If it has a very noticable groove, replace the part.
Check the condition of the thin o-ring that is behind the sprocket spacer. This probably needs to be replaced.
Replace the shaft seal if you have not already done so. I made a puller out of a long 1/4 hex head bolt to pull mine out. I ground half the head off of the bolt so that it would fit between the output shaft and catch on the inside of the seal. I then slipped a short heavy piece of steel with a hole drilled in it over the long bolt and then threaded a nut on the very end of the bolt. Use this tool as a slide hammer to remove the seal. Removing the seal this way WILL destroy the seal so have a new seal on hand as a replacement. (Or you can use the correct tool for the job!)
If your countersprocket is an aftermarket part and it thinner than the OEM part it can cause an oil leak. The sprocket/spacer combo has to press tight up against the o-ring mentioned above to make an oil-tight seal.
BTW, next time you rebuild the motor you should swap out the EXC head and flat head piston with a head and domed piston from the 05 SX 250. I just made this conversion and really like it. This is a common mod and wakes up the bottom end power. You can read more about this mod on www.ktmtalk.com.
This is the first KTM I have owned. I bought it several months ago and it seems to be in really good shape. I rebuilt the top end with the SX modification mainly because I wasn't sure how many hours the bike had on it. The SX conversion costs only around $100 more than a normal top end service since the only thing extra you have to buy is the head.
As far as I can tell my machine is completely stock except for the suspension which has been revalved by Bruce Suspension and slightly leaner jetting on everything except the main jet. I run Mobil 1 Synthetic 2 Stroke oil at 32:1. I also added a pair of Moose brush guards to the handlebars.
You need to spend a lot of time setting your suspension up. The KTM suspension is MUCH more finicky about setup than the japanese stuff. The correct shock spring rate and preload is CRITICAL on KTMs with the linkless suspension. Do a search for "GOLDEN RULE" on www.ktmtalk.com. Note that sag changed on the 03-04 KTMs and static should be in the 45-50mm range and rider sag should be in the 115-120mm range. If you are outside this range, you need different spring.
My KTM suspension was horrible when I got the bike. One problem I found was that the triple clamp bolts that retain the forks were too tight and were binding the fork movement.
Get a KTM manual (available on CD) for your bike. Good places to buy KTM parts are www.motosport.com and www.munnracing.com.
As far as I can tell my machine is completely stock except for the suspension which has been revalved by Bruce Suspension and slightly leaner jetting on everything except the main jet. I run Mobil 1 Synthetic 2 Stroke oil at 32:1. I also added a pair of Moose brush guards to the handlebars.
You need to spend a lot of time setting your suspension up. The KTM suspension is MUCH more finicky about setup than the japanese stuff. The correct shock spring rate and preload is CRITICAL on KTMs with the linkless suspension. Do a search for "GOLDEN RULE" on www.ktmtalk.com. Note that sag changed on the 03-04 KTMs and static should be in the 45-50mm range and rider sag should be in the 115-120mm range. If you are outside this range, you need different spring.
My KTM suspension was horrible when I got the bike. One problem I found was that the triple clamp bolts that retain the forks were too tight and were binding the fork movement.
Get a KTM manual (available on CD) for your bike. Good places to buy KTM parts are www.motosport.com and www.munnracing.com.
- Thread starter
- #8
Sounds good, i just got mine maybe 2-3 months ago. I really like it. But i tried getting on www.ktmtalk.com but i have hotmail so i couldn't register. I run Klotz super techniplate at 50:1, I have the stock manual but the guy i bought the bike from got it wet so i could use a new one.
