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Post by sayneric on Jan 8, 2011 10:09:16 GMT -5
Hurricane 50, something went horribly wrong inside the little guy.
Got it torn down (engine out, topend off and piston out). Top ring was welded into the piston, top of piston banged all to hell. Big chunks of shiny stuff on the con-rod and sprinkled on the crank as well. I'm thinking a crank bearing let go (5k or so miles on the engine, 2007 stock).
You will notice I said THINK, as I cannot figure out how to get the dang stator off. Nut is loose, washer off and it WILL NOT BUDGE. Help.
Also, what aside from a possible faulty oil injector pump would nuke crank bearings? I'm going to drop in a 72cc BBK and possibly a new crank, depending on the state of the current crank. I want to eliminate possibilities before I go and trash a BBK and a new crank.
The belt was a bit out of spec, and the CVT weights were a bit flatted, but nothing that (to my thinking) would setup vibrations capable of wiping the crank.
ONE MORE QUESTION, scrappydogs is pretty much the best place to nab stuff? Prices seem good and it's well organized. Any other places to poke around for parts?
Thanks
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Post by reveeen on Jan 8, 2011 10:50:19 GMT -5
The "usual" is a special stator puller (someone will chime in with the specific one you need), I have had luck in the past striking the end of the crank with a brass punch (AT YOUR OWN RISK!).
Your engine could have sucked in a reed, and it is for this reason, some folks use carbon fiber/fiberglass reeds. It is possible that you just had a bad bearing in there (from new) that just took this chance to blow up? Or maybe a nut/bolt/screw somewhere in the intake tract got sucked in? Maybe some crud plugged up the oil feed in the bottom of the oil tank? Nylon oil pump gear broke, or pin fell out?
ALL guesses, only you, with the stuff in front of you, can tell.
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Post by 90GTVert on Jan 8, 2011 11:26:21 GMT -5
:welcome: You'll need a 27x1.0mm left handed thread flywheel puller. I'm not a fan of beating on crankshafts. 49ccscoot.proboards.com/index.cgi?board=yamajog&action=display&thread=564Scrappydog is a great fast seller. I buy plenty of stuff from them... but I prefer 2T big bore kits from other places. I'm not saying they don't work, but one of our members had one and another member did some machine work for him. They didn't seem to think the metal used was of very good quality and I don't think the coating got good reviews either. This was regarding their aluminum big bore kit. Myself and other members have used kits from AUtotech355 on eBay. They aren't the best around, but they are decent quality at good prices. cgi.ebay.com/ebaymotors/Big-Bore-kit-70cc-12mm-CPI-Keeway-Vento-Exprole-1E40QMB-_W0QQcmdZViewItemQQhashZitem4cf444aa04QQitemZ330515655172QQptZMotorcyclesQ5fPartsQ5fAccessoriesHere's some nicer stuff. www.sip-scootershop.com/EN/main/base/Results.aspx?d=(sco,ape,lam,old,px,sma,max,atv,mot)&s=143e34356af749e0a181558a859d7938&a=1&sort=0&uc=(a5b87bd523bf45a685fafde69cbc9875) Parts For Scooters is a good spot to look for replacement parts as well. www.partsforscooters.com/s.nl?partner=49CCSCOOT |
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Post by reveeen on Jan 8, 2011 15:35:36 GMT -5
I'm not a fan of beating on crankshafts.
Neither am I, if you plan on doing this once in a while a puller is the way to go, I have used a brass punch in the past when I was stuck, leaving the nut on, and only hitting it once. If you mushroom the end of the crank (which is likely very soft) you have ruined it. If you do not wish to buy a puller, load the whole engine in the trunk of a car, and pay a few bucks to get it pulled at a motorcycle shop. Cash usually works wonders in this situation.
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Post by 90GTVert on Jan 8, 2011 16:38:48 GMT -5
Also, if you plan to work on any other scooters or small engines, it may be wise to order a multi-purpose puller rather than a single thread type. They cost a bit more, but less than each puller individually. www.partsforscooters.com/202-7-Fly-Wheel-Puller |
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Post by sayneric on Jan 8, 2011 22:48:27 GMT -5
90GTVert-
That first puller you linked (27mm) lists two of my motorcycles (YZ426 and WR250) as bikes it'll work on, so I think I'll spend 14 bucks at kneedraggers for that bit of kit.
Also glad you linked the oil pump delete as well, as I am going to yank that bit and BE SURE about my fuel mixture. I ride a KTM300 2t on regular occasion and the mixing aspect has never bothered me. I do tend to worry about wee little oil pumps being held responsible for an entire engine however.
Any links to really detailed microfische (exploded engine view)? Online shop manuals? If I can get a good picture of things I can work on just about anything.
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Post by 90GTVert on Jan 8, 2011 22:57:56 GMT -5
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Post by tomcas on Jan 9, 2011 13:34:58 GMT -5
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Post by sayneric on Jan 9, 2011 14:35:53 GMT -5
Danke. Oodles of info there.
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