Supersprox vs Dirt Tricks Ironman Sprocket Weight

Being a lightweight myself I like to keep my bikes light. The rear sprocket on a motorcycle is often a heavy steel part. You can get aluminum sprockets, but they often wear out very quickly. So the sprocket manufacturers have been coming up with cool ideas like making sprockets with aluminum centers and steel teeth or making sprockets of super strong spider webbed steel. I was curious which approach might be lighter.
So I weighed one of each! These are both 48 tooth sprockets for a KTM.

Supersprox 48T: 25.1 oz

Dirt Tricks Ironman 48T: 19.6 oz

Supposedly the Dirt Tricks Ironman sprocket approaches the weight of an aluminum one... but I don't have one handy to weigh.

While I was at it I weighed a pair of front sprockets. I had a OEM KTM sprocket and a Dirt Tricks one. Both are 13 tooth.

KTM 13T: 4.5 oz

Dirt Tricks Ironman 13T: 4.3 oz


I put the Ironman products on my bike.

I also heard rumors that it was a good idea to grease the splines where the front sprocket mounts. Supposedly the hammering away of the drive train wears down the splines and proper grease can help prevent this. Google around advrider.com and you will find lots of threads on that. At any rate, normal grease won't do, you want high a high pressure moly grease. Apparently most people use Honda Moly 60 Paste. It's cheap enough. Another recommended fix is the dirt sticks washer on the front sprocket. Its harder and and supposedly holds the sprocket in place better.
Here you can see I've applied the Moly 60 paste to the sprocket. I was careful to use as little as possible. I also put it on the sprocket, not the shaft, hoping that any excess would be pushed to the outside of the sprocket where it could easily be wiped off.

Here's a shot of the installed sprocket. I cleaned the threads with a tap and used new loctite. Note I have marked it so I can see if it ever decides to come loose.

I should also note that I have seen the WASHER turn , while the bolt remains tight. I called dirt tricks, and they said that happens sometimes... I'm not sure what to think of that. But as long as the bolt stays tight I figure things are good.

You have to remove the chain to make it easy to put the new sprockets on, so now's a good time to upgrade the chain guide. I went with TM Designworks RCG-KT3 in black. Its a nice heavy duty piece. Note mounting it requires you throw away the top chain guide. E-Ticket also installed a trick metal plate to protect the mounts:
http://ktmtalk.com/index.php?showtopic=440785&st=490
That's probably a good idea but as my riding isn't too rocky, and this guide does provide a little protection on it's own I decided to pass on that. Here's mine:

KTM Gas Cap Fix : KTM 350 EXC-F

New KTMs come with a fuel tank cap that often won't come off. It's really amazing KTM ships such a great bike with this common problem.
The problem is the button on top of the gas cap doesn't let you remove the cap sometimes. I'd heard this was often a problem, and when I picked up my new bike at the dealer yesterday I tried to remove the cap... and sure enough it didn't come off easily.

First, here are some tips if you get the cap stuck on:

• -There are three prongs that need to lift UP to release the cap. So you aren't helping if you are pushing down on the cap when you try to remove it. You need to pull UP on the cap at the same time as pushing DOWN on the button. If the cap is really stuck get someone else to push the button while you LIFT and turn the cap
• - Also, if you only push on the tab, that might only release the prong on that side of the cap, and if any of the three prongs stay down the cap won't release. Try removing the vent hose and push down on the center where the hose was. Don't use a using a tool to push as it is unlikely to help and will mar the cap. Just push firmly and make sure the button goes down all around, not just the tab on one side.

Summary: Remove the hose. Push down on the center where the hose is attached and watch to see the button is depressed on all sides. Pull UP on the cap while pushing down on the button. Turn the cap counterclockwise to open. Rotating back and forth (clockwise & counterclockwise) may help release the prongs if they are stuck.

Now the fixes:

1. Some people advocate loosening the screws on the bottom of the cap (this was shown in a Tech Tip in Dirt Rider magazine). This might help... but looking how the cap is built I wouldn't recommend it as a particularly effective solution.
2. Some guys have removed the orange three pronged widget from the cap and discarded it. Or just cut the prongs off. This results in a cap that doesn't lock on and makes the button non-functional. It may be unlikely that the cap will come loose in a fall, but I really don't like this solution.
3. Some guys trim the corner that the prong catches on in the tank. This could be a bit scary, as you don't want to drop any bits into the tank or accidentally cut your tank too much. However, it is a really good idea to inspect that corner to make sure a deformation or bit of scarf isn't holding up the release of the prongs.
4. My choice was to modify the prongs on the cap. This should work the same as modifying the tank, and if something goes wrong you have only hurt the gas cap. (Worse case is you just end up with fix #2.) I did the mod by removing the orange widget from the cap, trimming it, and then re-assembling the cap.

Here are some pics of the modified prongs. I did this carefully by removing the widget and shaving it with a sharp exacto knife. This cut corner makes a "ramp" that helps the prong get over the corner it catches on. Done carefully, the cap still latches but the button more easily releases the prongs so the cap can be opened.

Rumor has it KTM has changed the caps for 2014... we will see!

Pine Sol to Clean Carburetors

I have a bunch of carburetor parts to clean and recently read that Pine-Sol did a great job. So I tested it. Looking at the ingredients, I see this stuff is 1.75% glycolic acid. It did go right through my nitrile gloves and I had to switch to some heavy duty ones. And I did wear my safety glasses.
These parts have been soaked about 30 minutes, lightly scrubbed with a toothbrush and wiped off and then soaked for another 30 minutes. Then another light going over with a toothbrush and rinse with cold water. The part on the left is before cleaning, on the right is after.

Wow! Pretty good.