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The rebuild is going slow due to work, but I should finish it when the warm weather - the riding season comes :)
Meanwhile, here's a pic of the sweet sweet honed cylinder. http://imageshack.com/a/img908/504/uQUjJv.jpg http://imageshack.com/a/img538/1047/IraXO2.jpg |
When I bore my cylinders I take a face mill and just kiss the top gasket surface to make them perfectly flat and square with the bore. .003" is all need usually unless a person wants to up the compression just a bit, I've taken .012" off my last one and slotted the cam sprocket holes so timing can be adjusted. Usually non of this is necessary but I'm anal about stuff like that.
I'm keeping an eye out for one of those Aprilla sidestands , most are way different than yours. |
Soooo... back to the bike, during my free time.
The engine is completely disassembled. I've bought a gasket kit, Athena. Also all the oil seals of the right dimensions. As for the engine bearings I decided to keep the existing bearings, as they are in perfect condition. As well as all the gears and stuff. Everything looks great, I'm happy. The flywheel would not require a rebuild if not for the piston pin seat... it got a bit scored and the play (of the new piston pin) in the old con rod is too big compared to a play in the new con rod. The bearing in the con rod had no play, and I would not have gone to lengths to rebuild it. Only when disassembled the crankshaft showed some wear. It took 7 tonnes on one side and 10 tonnes on the other side to press out the con rod bearing pin. I've ordered a micrometer and two micrometer holders (because one micrometer I already had). Should arrive next week. In the meantime, today, I made myself a led hammer. I'll need that later on to true the crankshaft. Probably next week. So now what still waits: rebuild the crankshaft strip off the old paint off the engine re-paint the engine re-assemble it rebuild the cylinder head and give it some porting Not much, but with little time it's not going to be done soon. But I hope I'm wrong :) http://imageshack.com/a/img540/5905/ZTHynt.jpg http://imageshack.com/a/img633/9050/AJVXC1.jpg http://imageshack.com/a/img537/1765/dgp6Vw.jpg http://imageshack.com/a/img661/2787/Oz09WZ.jpg http://imageshack.com/a/img905/6296/WEIAtM.jpg |
How are you planning to press the crank back together perfectly lined up with each other, it is critical in pretty much every aspect to be aligned, not just straight. I've seen plates with the shape of the crank hubs for the top and bottom of the press so both halves are trued when they go together. I'd love to setup for doing these, be easy to do stroker cranks then !
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I don't have any cleaver jig to help me out, and I don't have the materials at the moment to make one. So I'll need to figure it out as I go.
Even if I would have a jig, the crank would still need to be trued with the two micrometers (one might be enough though) I have ordered and a led hammer that I made from scraps yesterday (copper hammer would do just fine too, or even better). I think I'll do something like this (start watching at 3:40): https://www.youtube.com/watch?v=HxcWz4D7BmA And truing: https://www.youtube.com/watch?v=saARVyy4pdY |
http://imageshack.com/a/img538/1098/vKi8Te.jpg
Kind of surprised you didn't drop the motor. Is there enough room for me to do base gasket with motor still in frame? |
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I didn't have much room on the shelves at the moment, and I didn't want the engine laying on the floor, so I left it in the frame. Until now, and now it's completely disassembled, I wonder how I'll put it all back together :rofl: easily, maybe... Mezo, I would gladly make something like that on my lathe, but I don't have a piece of metal big enough for that, haha! So an engineer's square will do for now, probably... |
Crank halfway done...
Today I have reassembled the crank back together. Turned out quite well, looks pretty close to being true, but I'll check that next day with a micrometer, after I make a jig to hold up the crank while I'm turning it and measuring. Firstly I pressed the pin into the right side crank half, where the oil feed is. After careful measuring I calculated that I need a 0.5mm washer to stop the pin from going too far, so that the oil feed passages are directly on top of each other. Then came the bearing and the con rod. The engineer's square got me a bit off at the first try, when I pressed the second half on (not fully on though). After the second try I got it spot on (I think :innocent: ). Big end side clearance is 0.35-0.65mm so I made it 0.5mm, the golden middle. But the crank is not 75mm wide, but 73.95mm wide, but the width is consistent over all perimeter. I think the big end side clearance is more important that the overall width... So that's it for now, truing to come. I don't know how my led hammer will perform, as it needed 15+ tonnes to press it all back together :rolleyes2: To be continued... http://imageshack.com/a/img538/3471/SRQOEM.jpg http://imageshack.com/a/img673/3513/EtloC4.jpg http://imageshack.com/a/img540/1487/SnAEaV.jpg http://imageshack.com/a/img912/1025/59h8J6.jpg http://imageshack.com/a/img540/3563/ljvsek.jpg http://imageshack.com/a/img537/9471/QgUUWr.jpg |
I'd say the clearance between the rod and crank halves is the key measurement like you said. I like to put things on the tight side of tolerances, keeps stuff quiet. The thrust on the side bearings can be adjusted with shims but to an extent. Total length between bearing shoulders must be held also to keep the crank from moving side to side.
Be fussy about things now, it'll pay off down the road with a smooth motor. How heavy is that lead hammer? might take a bit of pounding to get it to move. I like that jig Mezo posted , it should help keep those 2 halves lined up . As long as the hammer can get them to move and get into spec. :thumbup1: |
Done! Done! Done!
After making a simple jig to hold up the crank, I trued it with a micrometer. At the beginning it was 0.15mm off center at the shafts. So I got it pretty close with an engineer's square. With a bit of hammering I got it to 0.01mm at the right side and 0.02mm at the left side. Since around 0.04mm is okay (as far as I know), I got it better than required, and I'm happy about finishing the task I was dreading the most bier My led hammer is a bit over 2kg in weight. Took quite a bit of beating... It looks like the crank isn't moving, but it actually is. My crank didn't have any shims at the big end bearing, also the con rod kit didn't include any shims, so I made it as it was. Now I need some paint stripper, some paint, stainless bolts for all the engine, do the cylinder head and it can be reassembled. http://imageshack.com/a/img537/1668/wuGBba.jpg http://imageshack.com/a/img540/8193/TVhEts.jpg http://imageshack.com/a/img901/2738/Z0rTLk.jpg http://imageshack.com/a/img540/5857/eDB3Jf.jpg |
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Hello, where did you get the jets? What kinds did you end up with? Did you find all the correct parts you needed? I have ordered the carbs, and i will order the intake manifoilds as well. What kind of cables did u end up using? Looking forward to a reply. Fingers crossed:scooter::scooter: Ended up ordering these carbs: https://www.ebay.com/itm/392631109475 Any 1 know what kind of jets is used? Where i can order correct for the xtz 660? |
Zergamn = Belsm?
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I think not, Blesm just messed the quote up, fixed now. |
BTW - a tip on truing cranks - you can put it in a vise, kinda crossways a bit, using soft alloy jaws of course, and squeeze to align the wheels. Used to do two stroke cranks all the time that way. Then squeeze the faces or put a chisel in between to align the other direction. Rarely used a hammer except on the chisel.
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