1967 Yamaha YR1 350Presented by cyclelist |
Pictures |
 Right Side |  Left Side |  Front Wheel |  Guages |  Rear Fender |  Rear |  Left Muffler |  Muffler |  Engine Off. Everything was there, no mssing parts. |  On the bench, ready to take apart. |  Start with the right side. I did notice that the oil lines were loose on the cylinders, could have caused the problem with the bearings. |  Casing off, one clutch piece was broken off, someone had not had the propper tool last time clutch was taken off.... |  Oh yeah, had to make a tool to hold the clutch while I loosened the shaft. |  Cylinders removed, pistons look good, wrist pin bearing is worn out. |  Connecting rods seem ok, will have to check the specifications. |  Flipped the engine and loosened all of the bolts, time to split the casings. |  Engine split easily, hellow, what is the spring at end of red arrow and where did it come from? |  Crankshaft bearings were toast, should probably replace connecting rod bearings while I'm at it. |  All apart, I think everthing is shot, will need to spec it out. Did Yamaha make a rebuild kit? |  Initial press of other half, made plugs for rough alignment, the wrong way to do this... |  Pressing connecting rod lower pin in. |  Almost done the last press. |  Two sides together, now for the final alignment. |  Checking the alignment on the lathe of one half. Time for some v-blocks. |  Pressing the two pieces together |  Notice pieces of surface ground metal to stop cranks from squeezing together |  Together finally |  Crankshaft in homemade vblocks measured by dial indicators |  All the new parts ready to go back in. |  Before Bottom Casing |  Front of Top Casing with beginning polish started. |  Top casing with a lot of polishing already done. |  Checking that all bearings purchased actually fit. |  Putting on sealant |  Crankshaft, Transmission and Kickstart aligned properly after three attempts! Let the assemble continue! |  Clutch on, casing on. |  Putting the engine back on. |
Work completed, time invested, expenses, and lessons learned.
Had my brother-in-law pick up the bike today. Its in average shape. Numbers match between engine and frame.
Removed engine and split the casings. Now decisions need to be made about rebuilding the engine.
Pressed the crankshaft apart. Took a lot of force but eventually popped apart. Will need all main bearings. Connecting rod journalls looked worn. Connecting rods may also be shot. Connecting rod bearings surely shot as are the wrist pin bearings. All seals toast, may also need aluminum labrynth seal in the middle.
Looked on several sites to find parts. Tracked down a lot of obsolete engine parts on boat sites. Some on ebay.
<p>Had to make a lot of tools to get the crank back together. Vblocks, spacers, pullers.. It's back together and on reading very little wobble (within 1/1000) so I believe its ready to assemble. Spent a lot of time on this, but it was a good learning experience. Took time to make specialized tools. </p><p> Will wait for second opinion before re-installing into engine block. </p>
Started Cleaning Engine cases. Initialy Cleaned cases in parts cleaner, that got most of the grease off. Found that a dremel with a small wire brush will clean up everything the parts washer could not.
<p>Put in crank, transmission, and Kickstarter. Covered casing surfaces with silicone sealant. Assembled, checked kickstart, it was wrong... Took it apart again, then put it back together again... Seal in backwards, Apart again... Together again... </p><p> Made new shift spring. Cleaned up casing bolts. </p>
Buffed some more of right case, also assembled clutch and put cover on.
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