Tillerman6

Feetupfun, OK that's exactly what I needed to know. This pic is from a Craigslist bike for sale. Apparently my bike has the kit you mentioned. I was confused by the parts manual that I have. It shows a straight brake lever similar to mine. So what I will do is try and find a bent one like the picture above on Ebay. I think it would be best to have both versions on hand.

Guys, Does anyone know if this rear brake lever is off of another model (factory bend) or is it something anyone can do with a propane torch and a vice? Notice how the pegs are in the rear position and the brake lever is still easily accessable?

Feetupfun, After I rinsed out the pipe to get the degreaser out I dried it on the BBQ. It finally started burning on the inside and there was just enough o2 getting in that the smoke would keep going for about 4 hours. I am hoping that this treatment was enough as I think most of the obstruction was in the Silencer since it has that swirling restriction built in. I will know more when I get the cylinder and piston back from the shop. The outside was probably at about 250-300 degrees and the BBQ was running about 3/4 throttle all that time, but the outer shell did not turn colors which is probably a good thing for the metal to keep it's shape. I put some Blaster spray in both ends when it cooled off so it should not rust inside and taped over the ends to keep the air out a bit.

Another little update- I am baking/burning out the TY 250 A expansion chamber on my old propane barbque grill. There is no solvent being used. The contents seem to be slowly burning out the old oil. The Purple Power treatment did not get all the old oil out, so this is step number 2. I left the lid open about 2 inches and this seems to give it just enough oxygen to continue to smolder. It smells like oily smoke. This has been running for about 4 hours, but I want to continue until the smoke stops on it's own. Overall the pipe is laying flat, but the curved large end is up, and this is acting like a chimney effect to some degree. I don't have a deadline to meet so if it takes all day tomorrow too, that will be fine.

Feetupfun, The Purple Power is not flammable, as I suspected, but the instructions say not to let the chemical dry on the metal, so I rinsed it out with water and now it's on the barbie to boil out the water.

News flash! I had some of the old oil soaked glass that was removed from the spark arrester and just to see what would happen with a propane flame directly on it I tried to burn it up. The oil part burned pretty clean, but the glass would just glow orange. I don't think you could call it "melting" per se. It did ball up a bit around the edges, but it never got hot enough to get anywhere close to a liquid. So if it is under a wire mesh it will probably stay there. So it looks like it needs something like Acetone or some other flammable solvent to get it on fire and burn out all the old oil deposits. Just enough to wet the insides and then stand back and let it burn out. Once the oil in the glass ignites it will stay lit for a while. Might need some air to keep it going?

I don't know if I have ever tried to melt any fiberglass with a propane torch before. If the clean glass that shows up for re-packing the silencer will melt with propane, then that will be the acid test. If that melts, then melting out the old stuff in the expansion chamber will seem a lot more doable. Good thing it is not Kaowool in there as that stuff will not melt at all at least not up to 2500 degrees F. Propane is about 1350F so it would not do anything to Kaowool which is used for foundry furnace insulation. I am sure that the aceytaline rig would do it, and that will go to 6500, but I don't have that setup any more.

Well I would have screwed that up for sure. I was thinking of hanging it up on a steel coat hanger with the outlet end down. So that was mistake #1. The other mistake would have been heating the outside of the pipe with the propane weed burner instead of the inside. SO YOU DON'T HEAT THE OUTSIDE AT ALL??? And if the only way to stop the rust is to fire it up on the bike, then I will have to wait for the cylinder to come back from Millenium. Could I use some fogging oil for an outboard motor? and then plug up both ends until the cylinder gets back on? Thanks again for all the suggestions. I do really appreciate your help!

Feetupfun, That's a much better picture than what I had to start with. Since the wire mesh is pretty much against the outside wall, and welded to the outside wall to boot, it sounds like more of a hassle than it is worth to open it up. If there is anything remaining inside between the wire mesh and the outside walls it sounds like it would not interfere with normal operation once it was burnt and dried out. Right now it is drying a bit from a soak in the de greaser. I did not open it up yet, so thanks for that new information. Saved me a lot of hassle. I will go hang it in a tree and let the de greaser drain as much as possible before I light up the weed burner - this is from Harbor Freight and has a large flame coming out of it if you pull the trigger. I would assume that if the pipe is hanging up you would want the fat end down.? That way maybe something will fall out more easily? Or does it make any difference?

Twinshock dude- I like that response. Kind of generic info on the fork oil quantity. My forks are "generic" and I don;t know their source or history, but they do the job. 34 MM and the front hub and wheel are off of something else, but it all works fine. I just wish I knew what it was from.

Well that sounds do able. Were you working on a TY 250 for that decoke process? If so, when you re-packed the expansion chamber you had to cut it open? So where did you cut it and how did you seal it back up? What sort of mixture did you use for the caustic soda? What was the result of all that hard work? I have 2 pictures attached to this email. they are labeled "1" and "2" and they are on opposite sides of the rear end of the expansion chamber. would you look at them and tell me if those outlined areas are where you would cut if you were doing it all over again? Thanks in advance- Newbie to expansion chamber "surgery"

copemech, You are probably right about that spark arrester being most of the problem, but I want to fix ALL of the problem. I have a mig welder and a small machine shop, so it's not like the end of the bike if some part of the process does not turn out like it should. I think the expansion chamber will have to be opened up regardless of how the engine runs just for GP if nothing else. I know it will be a PITA but at least it will not be another possibiliy for trouble down the trail. Also, I think that it was probably junk in the two pipes that was causing most of my engine problems. The piston and jug were almost at their wear limits, but the noises the cylinder was making were probably more from the clogged exhaust. I'm just trying to figure out how to make the cuts so that it can be re-sealed with fasteners. This would be the best of both worlds because it will need to be re-packed several more times before I quit riding from old age.

I had two oil leaks on the left side. ONe was the clutch shaft seal which was leaking gear box oil and another was the left crank case seal behind the magneto plate. It was leaking pre-mix Mist and this was causing the points to corrode pretty fast and lose spark. I only have part number info for the TY 250 A's in 74 and 75 but if you need those numbers I can help you out.

Terry, I am trying to figure out how and IF I want to cut open the front expansion chamber (the big one) to clean and re-pack. The Tail pipe spark arrester was pretty much full of carbon chunks, so I figure the expansion chamber in front of that will be about the same. But I noticed that you say you have cut yours in half? Was that cut down the sides or which way?

Rock hopper, A new carb would be the next thing that my bike needs. I still have the old TK on it. So if you still have the information ( I know it's an old thread) That would be much appreciated! Thanks!

What about having the expansion chamber FULL of degreaser and then using a propane torch on the outside? It would boil the degreaser right thru the steel shell. That would also keep the shell from getting too hot. I just have to be sure the degreaser is not flammable. I suppose that would be like a poor man's hot tank? I think I would move the flame around pretty quickly and try to get the whole liquid mass boiling at the same time if possible.

I could see the degreaser liquid swirling as it exited the large end of the spark arrester pipe. Makes sense now. The hard part is going to be the expansion chamber. I should be able to find some sheet metal and make a patch for the hole I will be cutting in it. Do you want to have a look at the pics I put on that expansion chamber thread and tell me which side you think I should cut open? #1 side or #2 side or just have the part hot tanked?

copemech, that soak idea is a good one. I need to make friends with one of the shops in town that has a hot tank. It could not hurt anything to try that first. The goo is sort of baked on so it takes a lot of persuasion to loosen it up. Thing is you can't see inside to see what progress you might be making, so a lot of people would go a different route on this. My own soaking "tank" is not big enough to put the whole pipe in at once unless I lay it flat and pour in another 2 gallons or so of Purple power. That stuff is working but it works better with agitation. The little insert for the Silencer tail end pipe still has goo and fiberglass stuck inside and it has been soaking now for about 20 hours. The goo slows down the action of the degreaser after it works a while, but I think there is enough fizz left to give it one more day in the tub. Wish it was a hot tub.

Feetupfun and guys, Here are the pictures I just took that look like possible areas on the expansion chamber that look like they might be in an area where they could be patched back up again without too much trouble. They are labeled "1" and "2" They are on opposite sides. Any preferences? I am getting a bit braver now.

Feetupfun, Thanks for that reply. I will be looking for the pictures on here. The more information I can gather up the better. I don't want to cut it open any further than is needed. That oil soaked tin will be hard enough to weld back shut as it is. Someone has suggested rivnuts instead of welding. Maybe that is an option if the hole is large enough. I am going thru all the pages of emails and replies and I've got up to page 70. Haven't seen it yet, but it's interesting stuff all the same. "Heating it up to a high enough temperature" That is a little scary. Have you tried a propane torch on the outside at all? or is it more likely to work by putting the whole thing in a wood based fire? Also the "kerf" of the cut off wheel will be something like 1/32 to 1/16" so probably the best way to patch that back would be a larger piece overlapping the opening a bit and either using rivnuts and high temp silicone or tack welding the lid back on. Trying to butt weld the original piece back in would be a lot harder. But in any case it could all be done on the side facing the fender, so the patch would not show.

I need to keep the spark arrestor intact. We have so many natural (lighning) caused forest fires up here in the summer, I would not ever want to take a chance starting another one. right now I'm just waiting for the new packing to show up.

Tony, Your old thread post concerning the riding position advice has me wondering. I too am not so comfortable on my pegs if I use the rear most mounting position for the pegs. and I did not know there was a difference in the frames between a "Cat" model and a regular TY 250 A. IS there an easy way to tell which frame I have? It came with removable footrest brackets that move the foot rests forward about 4 inches for trail riding while sitting on a big cushy seat (which also came on this bike)

Alan_nc, I have a bike with something similar going on. When I took it apart one of the needles in the upper needle bearing was not there. Can't find it. bought a cheap borescope and looked under the con rod and as far along under it as I could. Not on the floor either. Still looking and have the pipes off for clean out. Silencer is clean. Maybe the front pipe in the goo, but I hate to split the cases for no reason. This bike is from a previous owner and he may have put it together that way. Don't know. Tried magnets no luck. Turned bike upside down no luck. Have not tried compressed air or any liquids under the crank. Any suggestions are much appreciated

I was emailed by Millenium Technologies today. (8/22/18) They changed what they were going to do to the cylinder and instead of a bore and Nikasil they are going to re-sleeve it and hone. The price dropped about 50 bucks so far from the original estimate. I will try and call them tomorrow and see what happened to make them change the order, but I would think it was the abberation at the intake port.

Thanks Tshock250 I am getting a lot of very useful info that I should have known by now, but my bikes before this one did not use any packing in the exhaust, so it was not in my memory banks to use.