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mcman56

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Everything posted by mcman56
 
 
  1. I made a bolt on plug for the engine side. It was over kill but I also added a 75 psi pressure relief valve. On the muffler end, I used an automotive rubber expanding freeze plug. To keep it from getting pushed out, I trapped the pipe in sort of a wood sandwich. (This was one of those activities that took on its own life.) Mapp gas heated it red hot and a small hammer was used to tap around the dent. It took some time but came out. The result looks a little lumpy but I'm not a great freehand craftsman. The pressure was right at 75 psi because the valve popped a few times. Next time I would try more pressure. before http://i103.photobucket.com/albums/m137/mc...er/DSC00391.jpg after http://i103.photobucket.com/albums/m137/mc...er/DSC00402.jpg http://i103.photobucket.com/albums/m137/mc...er/DSC00397.jpg set up http://i103.photobucket.com/albums/m137/mc...er/DSC00393.jpg http://i103.photobucket.com/albums/m137/mc...er/DSC00394.jpg http://i103.photobucket.com/albums/m137/mc...er/DSC00396.jpg
  2. Looking at the specs, timing for 2000 & 2001 2.9s is 2.7 mm. For 2003 it is close at 3.0 but the 2002 spec is 3.8. Why the difference? (The 2.5 specs show a similar pattern.)
  3. I have a friend with a couple of 280s. He would like something easier to start and does not need the power of the 280. It sounds like quite a few people converted 125s to a bigger bore so I figured that there should be some used 125 top ends for sale. If the 280 rod uses a bigger wrist (gudgen?) pin, it could likely be spaced down with a collar. That would even help the ballance. Machining and spacers could likely get a good mechanical fit but the port timing would be in question. I have some basic expereince with that but would have to get parts to measure the existing timing and calculate what the longer stroke would do.
  4. Can a 125 pro top end be put on a 280 lower end? Would a stroker plate and/ or cylinder-case spacer be needed? This would produce a true 200.
  5. MAX1956BIKES How much air pressure did you put in the pipes?
  6. I have a nice dent in the lowest part of my 2.9 header pipe. Pics are below. This has to be a pretty common dent area. Does anyone have experience fixing something like this? Searching the internet, I find two fix methods. Some great results are shown for freezing water in 4 stroke header pipes. However, this pipe section is somewhat oval and there is a seam that could get pulled apart. Then there is the pressurize with air and heat method. It sounds feasible and more controllable than freezing water but may have risks with names like bomb and cannon. http://i103.photobucket.com/albums/m137/mc...rco_pipe009.jpg http://i103.photobucket.com/albums/m137/mc...rco_pipe008.jpg http://i103.photobucket.com/albums/m137/mc...rco_pipe007.jpg http://i103.photobucket.com/albums/m137/mc...rco_pipe006.jpg
  7. I don't have the skill to do that kind of welding. (someday I need to take a class) What do you think a shop would charge? I ordered some parts at RYP this week and inquired about muffler prices. The guesstimate was around $270. (I did not ask to check the actual.) Delivered, that has to be close to $300. Another option is what patoche did. Not as pretty as welded but looks like something the average person could do. It may be worth a try before throwing the existing one in the trash. http://ppat61.free.fr/Sherco/
  8. Thanks....the pictures are not bad but now I'm a little confused. I see two punched sheet metal plates with holes for rivets or screws and one cover plate. How does all of this go together? Do you weld the punched plates to the muffler....one in front of the central barrier and one behind? Are there actually two cover plates...one front and one back? Or?
  9. When looking through these posts there are two people that mention a riveted assembly. "Chris" has a link to pictures on trialstalk but the link is dead. The "French Guy" has a link to a French site but I don't see anything there.
  10. I'm considering a muffler repack on a 2.9 and did a search for old posts. There are some pictures for the cutting and welding but I also see some references to using rivets for reassembly. This would really ease future repacks but all of the links to pictures are dead. Does anyone have pictures or links to pictures for reassembly with rivets?
  11. "Deep cervical work using a BP cuff or biofeedback device" I assume this is a relaxation exercise. What type of "BP cuff" is needed? Do you need a continuous readout or just sample every couple of minutes? Would the inexpensive wrist type work?
  12. A weightlifting coach once told me that there was an old lumberjack trick for toughening up hands.......urinate on them. Supposedly, the acid in the urine would have some toughening effect on skin. I considered but never tried this "therapy". The hook grip combined with quick movements and deep knurling could really tear up hands.
  13. Do you recommend olympic style squats...where calf touches thigh at the bottom? Would overhead (snatch postition) squats have the same effect? What about deadlifts? Should they be powerlifter style?
  14. billycraig...could you be more specific on your trials training? What kind of reps and sets do you do?
  15. Back to Drilling Discs.......Do the drilled holes help prevent or minimize brake squeel?
  16. There are a whole bunch in the 7/8" size. http://www.renthal.com/application_result.asp?type=33 Measurement wise they look like the 6.0" 768-02 but I'm short and they do not seem tall so that probably is not it.
  17. I am looking to upgrade an 02 Sherco to fat bars and would like to have the height, rise, sweep, etc of what is on there now. (I realize I could measure this but figure it would not be real accurate.) The bars are stamped 60 507176 but when I go to the Renthal site these are not listed. Am I missing something?
  18. The TLR200 Reflex carb is the same as the TL125 and I believe most if not all Honda 125 carb bodies are the same. I have even seen what looks like China made coppies on the internet. They were being marketed as a modification for bikes like the XR100. These have the same oval bore and were speced as 22mm. When looking at the engine side of the carb, the bore is offset to the bottom.
  19. Boysen power reeds can also help make it more user friendly. My 1997 270 had a little "hit" or step in the powerband just a bit up off of idle. The Boysens smoothed it right out.
  20. If you can not find a head spacer, you could have one made. I had to make one for a 1997 Beta. If interested, I could provide details on what needs to be done. A weight could also be made.
  21. My 2.9 has mainained the cleanest airbox of any dirt bike I have had. However, I recently notice a very fine dusting of very fine dust in the box. I'm in CA and have been riding in extremely dry dusty conditions but have not noticed this before. Is this normal or to be expected? There are no tracks or signs of an air leak. I cleaned the box and leak checked by filling with water. The filter is good and I use that super sticky Belray oil. The carb was almost perfectly clean. I recently replaced the box and may be looking at it a little more closely than before.....stimulating a little paranoia maybe???
  22. mcman56

    Pampera

    Crikey!!! Well, his name is Gadget
  23. mcman56

    Pampera

    After pressing POST, I realized the equation can be made much simpler. For your calcuations G, D, and d are constants so: F2/F1= n1/ n2 or % increase in stiffness = (n1/ n2) x 100 or n2 = (n1 x 100)/ % increase in stiffness
  24. mcman56

    Pampera

    If full compression is not near coil binding the springs, one option would be to cut your existing springs shorter. Basically a shorter spring is a stiffer spring. I have done this on a TY250 mono and a TLR200 with good results. Springs can be cut with a hot saw or small grinder. If necessary, the cut end can be made flatter by heating and bending flat or even a little grinding. You will then need longer spacers to set proper sag. Put a steel washer over the cut end because it will probably not be as flat as a spring manufacturer can make. The question then becomes how much to cut. If you can stand a little engineeringish, the formula for calculating spring force is: F = (G d**4)/( 8 D**3 n) where ** is for exponent..that is d**4 = d x d xd x d G = shear modulus = 11.5 x 10**6 PSI for steel d = wire diameter of the spring D = mean coil diameter of the spring or (coil ID + Coil OD)/ 2 n = number of active coils Since the number of coils is in the denominator, you can see that more coils makes for a lower spring force. So.... calculate the rate for the existing springs. Estimate how much stiffer they should be...(10%...20%?) Then run the calculation backwards to see how many coils to cut off. Verify that they will not coil bind with that many coils and then cut away.
 
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