Author Topic: zx50 wont start  (Read 2745 times)

LoveMyKymco

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zx50 wont start
« on: May 06, 2012, 10:29:58 PM »
It started for 3 seconds running really low idle and rough then as soon as I tried to give it any gas it died, then if I kick it over a lot in a row it will kinda fart out the pipe for a half second. I just got it for 100 bucks because it didnt run and i tore it down, cylinder walls looked fine and rings were still hard to compress back into the bore when reinstalling. Possibly the gaskets may be leaking but I doubt it. I wish I had a compression tester.
Does it sound like crap compression or flooding?
Its a
03 kymco zx50 super fever with a (whats looks to be 47mm) big bore kit, big sport expansion chamber exhaust that looks like my motorio, a Ct chrome intake with 24mm carb and 38 pilot and 112 main jet in it with a Uni pod filter. Stock CDI and orange performance coil.
Definitely gets spark as my tach will hit 1600 rpm with me kicking it like a banshee, and I see fuel flow thru the filter and it runs out the drain when I unscrew it.
Thank you for any help with this. I have another 03 kymco that I ride that Im thinking about swapping parts onto this one.
My 82 mph Killer Full MHR zx50 build (now 91 mph gps verified)
http://www.kymcoforum.com/index.php?topic=7795.0
My Fabrizi/MHR "can it cost anymore?" build
http://www.kymcoforum.com/index.php?topic=12146.0;topicseen

donut

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Re: zx50 wont start
« Reply #1 on: May 06, 2012, 11:10:06 PM »
wow , go get a $20 compression tester ....

zombie

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Re: zx50 wont start
« Reply #2 on: May 06, 2012, 11:15:57 PM »
Agreed. Do a compression test, And a vacuum test on the engine. If there is a TINY leak in the cases/seals it won't run. There is no other route to take yet. Remove the carb, and the exhaust. The case should hold 6" of vacuum for 6 minutes. Same for pressure. 6lbs for 6 minutes.
After passing that it is time to try other things.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

LoveMyKymco

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Re: zx50 wont start
« Reply #3 on: May 07, 2012, 05:05:06 PM »
Heya zombie, what do you suggest I use for the pressure tests? My friend has a radiator leak tester, would that work or is there a easier way with a might vac or something? Thanks for the advice.
My 82 mph Killer Full MHR zx50 build (now 91 mph gps verified)
http://www.kymcoforum.com/index.php?topic=7795.0
My Fabrizi/MHR "can it cost anymore?" build
http://www.kymcoforum.com/index.php?topic=12146.0;topicseen

Shaka

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Re: zx50 wont start
« Reply #4 on: May 07, 2012, 09:10:04 PM »
Typically you have to make a Leak-down tester.  Areomyst sells a real nice one also.  Here is a pic of the one I made...about the best tool to have for these 2T's!!!!


LoveMyKymco

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Re: zx50 wont start
« Reply #5 on: May 08, 2012, 04:35:58 AM »
Sweet tester, Looks efficient and neat! Thanks for the pic, it does more than a thousand words could describe.
My 82 mph Killer Full MHR zx50 build (now 91 mph gps verified)
http://www.kymcoforum.com/index.php?topic=7795.0
My Fabrizi/MHR "can it cost anymore?" build
http://www.kymcoforum.com/index.php?topic=12146.0;topicseen

LoveMyKymco

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Re: zx50 wont start
« Reply #6 on: May 09, 2012, 05:17:22 AM »
45 psi just wont let it fire I guess, haha.... Malossi MHR 72cc aluminum BBK here I come. Ill have and had the 50mm taiwan on my blue and grey zx50, malossi MHR 72cc on the grey and white zx, polini corsa 72cc on the 89 elite with AF16,lastly my favorite the 65cc malossi iron bbk for the Af05E on the OG Madmax 89 elite(its equiped with real bull and deer horns/antlers)
but damn 45 psi, how does it even get that bad.
« Last Edit: May 09, 2012, 06:22:32 AM by LoveMyKymco »
My 82 mph Killer Full MHR zx50 build (now 91 mph gps verified)
http://www.kymcoforum.com/index.php?topic=7795.0
My Fabrizi/MHR "can it cost anymore?" build
http://www.kymcoforum.com/index.php?topic=12146.0;topicseen

zombie

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Re: zx50 wont start
« Reply #7 on: May 10, 2012, 01:52:10 AM »
My guess would be a sudden failure... Snapped ring/scored Cylinder.
I melted a few pistons in my day, and the 50mm Taiwan was the latest. When I pulled the jug the Boost side skirt on the jug was cracked soo far across that when I set it on the bench the skirt just fell off. One more minute of riding, and It would have trashed my entire engine.
Stick with the good parts Bro!
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

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