Hey Folks:
After sitting in my garage since it's last ride out to Jawbone Cyn/Dove Springs/Redrock Cyn (CA) in 2000 (yes, I know that was a very long time, but life happened,,,) I got the urge to cleanup the "Blue Bomber" and get back out on the trail.
Everything mechanically on the bike is original as far as I know (I purchased in 1991), so I needed to care for some issues that had cropped up like the steering head bearings had gotten stiff and notchy.
The bike prior to be taken apart looked like my avatar above which I did not save to the camera roll, so you'll have to just squint I guess. To my knowledge, the head had never been off so tonight I took the head off and pics are shown below

















Do you 2 stroke experts see and land mines in the cylinder?? Considering it's 31 years old on the original piston & rings, it looks good to my eye ( but that's why I'm reaching out to those that are "in the know".

I'll be digging into the clutch as the plates seem to be stuck together, and those pics will be another day.

Thanks all!

PS - some of the restorations here in this forum are amazing. There are true master mechanics and craftsmen hanging out here!

Looks pretty good to me brother- I would just decarbon the top of piston and inside Cylinder head and put it back together.

Once you get it running then you can really start dialing it in by seeing and hearing issues and what next steps are needed- Possible issues will be- Air Leak- oil leaking- piston rattle etc.

Before I start any clean up or Resto work on a bike- I first make sure the bike is brought up to safety standards- new brake pads- cables etc... and then ride it. This will allow you to make notes and fix any obvious issues along the way and what will be needed if you do a tear down.

Thanks Greg.
I have two "technique" questions:
1. How do you de-carbon the head & cylinder? Is that just a matter of scraping or do you have some other process?
2. How do you de-carbon the exhaust system? The pipe and silencer look very good inside, but beings they are off the machine I might as well take care of that. I have seen some videos on this forum where fire/smoke is coming out of the pipe, but I did not see what fluid/chemical was first poured in the pipe.

New EBC grooved pads are on the way for front/rear, new Uni air filter, new chain, etc.

You seems to be a jetting master on the "Black Widow" and the white IT (maybe call that "White Lightning"??). I run a 370 main and 40 or 45 pilot jet with the clip in either 2nd or 3rd slot depending on elevation ridden. I live a 300ft, but will be riding in the Sierra Nevada mountains at 4,000 to 6,000ft, and out in the desert which would be maybe 2,000ft. I have never felt the jetting was spot on, but just don't know how to diagnose what I'm feeling on the bike with changes at the carb. It's just a rather inexact science seemingly.
Thanks for your valuable thoughts,
Brian

Looks good to me as well.All I would do is use a bottle torch on the crown to heat up the carbon till it flashes over to gray,then sand off the crust. same on the bore but a light hone after flash,fresh rings and rechampher any sharp edges around the ports.I like a bit more angle on the top and bottom of the exhaust port.Flush the barrel out with solvent and blow dry with my compressor and immediately spray some light oil into it.Reassemble with new gaskets and circlips and the wrist pin bearing while I was in there.I would also change both crank seals as well to be honest.Good luck!

looks very good to me too. I would do what G.French suggested myself,clean the carbon out and clean out the pipe would be the only thing I would vary on. get out and ride it and check for any issues. the advice given is rock solid!

to all of the above.

Could just be the lighting, but it looks to me like there could be signs of blowby in the cylinder bore? (vertical brown streaks)

Considering the age and history, I'd probably pull the cylinder and have the cylinder and the piston measured to see if they are still in spec.... but that's me.

P.S. I've never used a torch to remove carbon from a piston or head... I'd be afraid of warping something. Careful scraping is usually what I do... the rounded end of a hacksaw blade and a gentle touch works well... you don't want to scratch the aluminum

yeah,I would soak the carbon with carb cleaner to soften it and use a wooden spoon like device or another soft material,plastic scrapers also work very well.

the torch itself I use to burn out the goop in the pipe.

avoid scratching the piston crown and head,if scratched it can cause hot spots and it could lead to detonation also known as pinging.

I have found using a little dab of 2 stroke oil and some 600 grit wet/dry sand paper works great to cut the carbon and it makes a big black liquid spot- then just wipe it down.. May take a couple of passes but it will come loose.

For Jetting- I have ridden my IT 490 at sea level in California all the way up to 13,000 ft peaks in Colorado and never changed my current jetting- runs awesome.

I have mine set up with- 340 Main- 40 Pilot- 3rd clip position from top on needle and Air Screw out 1 1/2 turns.

I run a 32:1 Premix- Perfect mixture and just the right amount of smoke...

Greg, to your knowledge is the jet needle the "stock" 6F39?
It's amazing that the jetting works for both your altitudes in CO and at sea level in CA.
Biknflyfisher



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