Author Topic: 80cc big bore  (Read 2946 times)

Scuzz

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80cc big bore
« on: December 24, 2011, 06:16:38 PM »
OK, I've installed an 80cc big bore kit in my 2006 agility. The bike would start but cut out, but now it wont start at all. I have installed a #94 jet in the carb etc. Would I need a larger pilot jet? Could it be the exhaust? Any help would be appreciated.
« Last Edit: December 24, 2011, 06:20:55 PM by Scuzz »

Scuzz

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Re: 80cc big bore
« Reply #1 on: December 24, 2011, 06:33:35 PM »
I've also checked the spark plug

blue

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Re: 80cc big bore
« Reply #2 on: December 24, 2011, 09:27:59 PM »
the best thing would of been to leave it as a 50. I would of loved to do that too but everyone I know that has. Had problems later. Happy I did now. I have a agilty also its a 07 and running good yet. good luck. sorry to sound rude but just saying it as I see it.

Scuzz

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Re: 80cc big bore
« Reply #3 on: December 24, 2011, 09:48:03 PM »
Maybe you're right but it doesn't help my situation, thanks anyway.

sidthesloth

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Re: 80cc big bore
« Reply #4 on: December 24, 2011, 10:10:27 PM »
Do you have spark? Are the valve clearances correct? Is the valve timing correct?
ZX50, 47mm cyl. kit, TZR50 CDI. Michelin Pilot Sport tyres,
Next performance mod; pumping the tyres up.

sidthesloth

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Re: 80cc big bore
« Reply #5 on: December 24, 2011, 10:16:59 PM »
Blue, I have two sym vs scooters, a 125 and a 150, the only difference is the cylinder/piston. the only difference in the tramsmissions is the roller weights, 10 v 14 grams and the drive boss is 1mm shorter on the 150.
ZX50, 47mm cyl. kit, TZR50 CDI. Michelin Pilot Sport tyres,
Next performance mod; pumping the tyres up.

Scuzz

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Re: 80cc big bore
« Reply #6 on: December 24, 2011, 10:17:59 PM »
OK I haven't checked the valve clearances, but there is a spark and the timings are correct. Cheers

sidthesloth

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Re: 80cc big bore
« Reply #7 on: December 24, 2011, 10:21:21 PM »
If you haven't done so already, it won't hurt to recheck the valve timing, for peace of mgpgnd if nothing else. Is fuel getting through to carb and cylinder ok?
ZX50, 47mm cyl. kit, TZR50 CDI. Michelin Pilot Sport tyres,
Next performance mod; pumping the tyres up.

Scuzz

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Re: 80cc big bore
« Reply #8 on: December 24, 2011, 10:25:10 PM »
Yeah I think the fuel is getting through OK

sidthesloth

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Re: 80cc big bore
« Reply #9 on: December 24, 2011, 10:36:39 PM »
Is your spark plug wet with fuel?
ZX50, 47mm cyl. kit, TZR50 CDI. Michelin Pilot Sport tyres,
Next performance mod; pumping the tyres up.

Scuzz

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Re: 80cc big bore
« Reply #10 on: December 24, 2011, 10:42:50 PM »
Yup

sidthesloth

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Re: 80cc big bore
« Reply #11 on: December 24, 2011, 10:53:06 PM »
How is your compression, if that is ok then it is back to valve adjustment/timing.
ZX50, 47mm cyl. kit, TZR50 CDI. Michelin Pilot Sport tyres,
Next performance mod; pumping the tyres up.

Scuzz

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Re: 80cc big bore
« Reply #12 on: December 24, 2011, 10:58:52 PM »
I haven't got the right device to check compression. Are you sure it's nothing to do with the jets?

sidthesloth

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Re: 80cc big bore
« Reply #13 on: December 24, 2011, 11:07:31 PM »
It should run if you have fuel, ignition and compression. If not enough fuel it would run rough, but should still run.
ZX50, 47mm cyl. kit, TZR50 CDI. Michelin Pilot Sport tyres,
Next performance mod; pumping the tyres up.

REDKYMCO

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Re: 80cc big bore
« Reply #14 on: December 24, 2011, 11:20:16 PM »
I have never really looked into the idea of fitting a big bore kit but i would have thought as you are fitting a bigger cylinder then you would also need a larger carburetor to allow for the extra air the scoot needs to breath in and larger exhaust for the higher volume of output, otherwise i would have thought you would be choking the engine......
IF IT IS NOT BROKE DONT FIX IT:)

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