06-13-2013, 11:19 PM | #1 |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
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how much pressure is normal in the crankcase?
i am sooo dang close to getting this thing running, but i keep finding more and more stuff... got spark with the old harness bits, and the new cdi... throw some gasin the tank, no bang...pull the carb cleant he jets out because they were clogged shut...try again... still no bang...next on the list, check the valve clearances...intake valve was wwaaaaayyyyy too tight... i backed it off a full turn to get it to .05 tolerance...try again...still no bang, but it sounds like it may be trying (had one kick over 3 revolutions, but that was it...) as i crank it over with the e start, i notice a good bit of air coming out the crankcase vent...i am thinking i may have some serious ring issues if theres a good bit of air there?
any ideas? also, turned out that the old cdi is still good... i get spark with that too...LOL oh well... i am waiting on my new harness to show up, but i can get spark now, i wanna hear it run...i am fearing the worst though that it will need rings minimum... gotta figure out how to drop the engine out of the frame soon to see about puling the head and getting a look deeper inside this thing... moral of the story... if the seller says itjust lostspark, dont always believe him... |
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06-14-2013, 01:16 AM | #2 |
Join Date: Jul 2008
Location: Idaho
Posts: 25,054
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Please remind us; what bike are you working on?
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Spud "Never argue with an idiot. He will drag you down to his level, and beat you with experience." Mark Twain 2015 Zongshen ZS250GY-3 (RX3) 2006 Zongshen ZS200GY-2 (Sierra 200) 2005 Honda XR650L 2004 Honda CRF250X 1998 Kawasaki KDX220 Mods made to my Zongshen ZS200GY-2: http://www.chinariders.net/showthread.php?t=6894 |
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06-14-2013, 01:34 AM | #3 |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
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Oops sorry, shineray xy200, 200cc pushrod motor, seems lifan based...
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06-14-2013, 01:58 AM | #4 |
Join Date: Jul 2008
Location: Idaho
Posts: 25,054
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Thank you for the reminder.
I think it's time for a compression test. I use an inexpensive, yet effective compression tester I bought at Harbor Freight. http://www.harborfreight.com/quick-c...ter-95187.html
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Spud "Never argue with an idiot. He will drag you down to his level, and beat you with experience." Mark Twain 2015 Zongshen ZS250GY-3 (RX3) 2006 Zongshen ZS200GY-2 (Sierra 200) 2005 Honda XR650L 2004 Honda CRF250X 1998 Kawasaki KDX220 Mods made to my Zongshen ZS200GY-2: http://www.chinariders.net/showthread.php?t=6894 Last edited by SpudRider; 06-14-2013 at 01:12 PM. |
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06-14-2013, 08:46 AM | #5 |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
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I was going to do so last night, but it would appear that my HF compression tester doesnt have the appropriate adapters for the smaller spark plug hole. Mine only fits standard automotive sized plugs... Guess i gotta look for the proper adapter...
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06-14-2013, 11:10 AM | #6 | |
Join Date: Mar 2009
Location: Sardis, BC, Canada
Posts: 25,977
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Quote:
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Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer |
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06-14-2013, 11:19 AM | #7 |
Join Date: Mar 2009
Location: Sardis, BC, Canada
Posts: 25,977
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Was this what you meant, Spud? http://www.harborfreight.com/compres...kit-66216.html
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Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer |
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06-14-2013, 11:22 AM | #8 |
Join Date: Mar 2009
Location: Sardis, BC, Canada
Posts: 25,977
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BB, I've never tried to measure the pressure in the crankcase, but I would expect it to be a noticeable amount. It should inhale / exhale as the engine is turning over, but that might be interpreted as exhaling only. it would be interesting to attach a vacuum / pressure gauge on a healthy four stroke to get a baseline. Hmmm...
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Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer |
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06-14-2013, 11:34 AM | #9 | |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
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Quote:
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06-14-2013, 12:57 PM | #10 |
Join Date: Mar 2009
Location: Southeastern Washington desert
Posts: 14,761
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I don't think you can feel the vacuum on a crankcase vent although I have never tried. They just seem to gently blow.
Some oil dripping is normal too.
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06-14-2013, 12:58 PM | #11 |
Join Date: Mar 2009
Location: Southeastern Washington desert
Posts: 14,761
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A thumb makes a usable cursury compression gauge. If you push as hard as you can, choke off, throttle wide open and crank the engine it should smartly blow your thumb off no matter how hard you press. This will suggest the compression is over 100 PSI.
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06-14-2013, 01:14 PM | #12 | |
Join Date: Jul 2008
Location: Idaho
Posts: 25,054
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Quote:
http://www.harborfreight.com/quick-c...ter-95187.html
__________________
Spud "Never argue with an idiot. He will drag you down to his level, and beat you with experience." Mark Twain 2015 Zongshen ZS250GY-3 (RX3) 2006 Zongshen ZS200GY-2 (Sierra 200) 2005 Honda XR650L 2004 Honda CRF250X 1998 Kawasaki KDX220 Mods made to my Zongshen ZS200GY-2: http://www.chinariders.net/showthread.php?t=6894 |
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06-14-2013, 01:29 PM | #13 |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
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The tester i have isnt listed on thier site anymore, but it was half the cost of all the other ones....i need to find an adapter and see....LOL im sure i can fine something...
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06-15-2013, 12:46 PM | #14 |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
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got the right fittings for the compression gauge, checked compression, made a whopping 60#....well, tore into the top end, and that suckers rings (exceot for the oil rings are SHOT....top ring was cracked, both combustion rings are STUCK in the piston...oddly enough, the bore is spotless...not a single scuff or scratch.... will be good as new with a basic hone, and a new set of rings....
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06-15-2013, 02:30 PM | #15 |
Join Date: Jul 2008
Location: Idaho
Posts: 25,054
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Good work, BB. I think that's the first time I have heard of a cracked piston ring.
You can certainly get piston rings from Taobao. In fact, a new piston is probably quite inexpensive, as well.
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Spud "Never argue with an idiot. He will drag you down to his level, and beat you with experience." Mark Twain 2015 Zongshen ZS250GY-3 (RX3) 2006 Zongshen ZS200GY-2 (Sierra 200) 2005 Honda XR650L 2004 Honda CRF250X 1998 Kawasaki KDX220 Mods made to my Zongshen ZS200GY-2: http://www.chinariders.net/showthread.php?t=6894 |
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