You might try asking GFrench... if I remember correctly, a tried and true method of sealing is installing the pipe with a generous amount of high temp silicone, letting it dry completely before starting. After starting (without muffler/spark arrestor installed) a ring of excess silicone seal will pop out the exhaust when revved up... Greg would know best and might have a recommendation. (I've never tried this method as all my current bikes have either o-rings or bolt-on flange connections with no springs or slip joint.)


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First make sure you have the Gasket that fits inside the pipe first-

3R4-14613-00-00 GASKET, EXHAUST PIPE

I use permatex Hi Temp Ultra Copper on all of my exhaust/manifold connection points.

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The real key here is to apply and nice bead on the front edge of the inside of the exhaust pipe and a bead on the front edge of the actual Manifold- let it set for about 5 minutes before you push the pipe onto the exhaust flange.

This allows the sealant to start curing a tad and will give you a nice seal. Once you push the pipe on- hook up the front springs to hold it in place and then bolt the pipe down. You want just enough sealant to form a nice ring around the pipe when together- if you apply to much you will have one big goopy mess!

I then I let it cure for a good 48 hours before I start it up and has worked great!

Nothing worse then smoke and oil coming out of this area!

Thanks Greg, that's great info!
I did indeed install the new exhaust gasket as part of the restoration thinking it would cure the problem, but I can see that something more is needed - and you have delivered in spades!! (I had this same problem the last time the IT was ridden out in the desert, and it was a real mess. But, I also believe I was running too rich at the time).
The IT and YZ are going to have some fun playin' around in Hungry Valley, that's for sure.
It's going to take a bit to get my "off road legs" back after being on the street for so long. I took my FJR1300 out for a 75 mile spin yesterday afternoon after riding the IT490 earlier (up and down the street), and talk about a paradigm shift in bike weights - I just about dropped the 650lb FJR,,,,,
Brian the biknflyfisher

Hey- This gasket sealer is exactly what I need !!!!!! My IT465 leaks - and I have not looked into the fix but here it is!!

See the gap I'm talking about?? This is with all factory/stock attachment parts,,,



The paint on the side panels has pretty much cured, with only a few paint "boo-boos". I should be able to clean this up with a bit of work. Not show worthy, but then again this is a "riding bike".



Notice the FJR1300 in the background photo-bombing the shot,,,,
biknflyfisher

Now that the Blue Bomber is back together, I rode down at Hungry Valley yesterday to see after a 15 year hiatus how the bike AND I would do,,,,,
Here's how he looks after 57 miles of dusty/gravelly/sandy roads and trails:






Observations:
1. After riding a street bike where the front wheel is always planted on the road, it's really a weird feeling having the bike drift around through corners. After a few hours, it all seemed natural again.
2. The jetting still needs work.
3. The head pipe/ manifold junction needs work, as it did spooge some crap out on the engine and frame down tube. I did not have time to do GFrench's copper-stuff treatment, I plan on doing that along with some addl work on how the exhaust is mounted to the frame under the tank.
4. Vibrates like a son-of-a-gun.
5. With an IT490, you NEVER say " I wish I had a bit more top end power,,,". Wow,,,,,
6. Oh to have modern disc brakes! I climbed a steep hill, only to have the brakes lock up and kill the engine on the way down. Many other times in the twisty bits the rear brake just locks under even moderate pressure. I had a chance to ride a guy's KTM EXC 400 who was eye-balling the IT, and what a set of beautiful brakes! He dug the ride on my IT by the way,,,
7. The 32:1 mix produces the right amount of smoke and beautiful 2 stroke smell. I did meet a guy going the other way who was running something with Castor oil in the mix - that is such a great smell! Maybe Blendzall??

So, back to working on the bike for the HV trip on the 27th and 28th.
Brian the biknflyfisher