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 Post subject: 1979 yz400
PostPosted: Sun May 02, 2010 3:13 pm 
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Joined: Sat May 01, 2010 7:32 pm
Posts: 4
I have a 1979 yz400 that i just rebuilt, but it will not start cold unless you put fuel in the cylinder. once you have had it running it will restart first try. any ideas? thanks Todd


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 Post subject: Re: 1979 yz400
PostPosted: Mon May 10, 2010 1:45 pm 
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Joined: Wed May 05, 2010 2:05 pm
Posts: 2
You may have slightly low compression. If that were the case, it could make it difficult to suck fuel through the carburetor into the cylinder when using the kick starter. Have you tried bump starting while it's cold? I would recommend checking the compression and see if it is up to spec.


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 Post subject: Re: 1979 yz400
PostPosted: Mon May 10, 2010 3:05 pm 
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Joined: Sat May 01, 2010 7:32 pm
Posts: 4
haven't tried bump starting but will check compression again. the bike has a new top end.


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 Post subject: Re: 1979 yz400
PostPosted: Mon May 10, 2010 5:59 pm 
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Joined: Sun May 09, 2010 11:32 am
Posts: 9
Location: Rancho Cucamonga, CA
hi, would also do a leak down preasure test. the bottom end seals and bearings could be bad,terry

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79 RM 400 (2), 79 CR250, 80 CR250, 80 CR125, 82 Husky WR430, 72 Rickman 125, 71 Hod 100 SR, 73 X75, 76 Hon TL125, 74 XL350, 79 XL500, 00 KX250, 00 YZF426, 04, 06, & 08 CRF450, 06 CR250, 05 CR85, 74 GT550, 85 350X, 83 200X, 80 Yam 125.


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 Post subject: Re: 1979 yz400
PostPosted: Tue May 11, 2010 1:50 pm 
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Joined: Sat May 01, 2010 7:32 pm
Posts: 4
will give that a try thanks.


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 Post subject: Re: 1979 yz400
PostPosted: Tue Nov 16, 2010 11:22 am 
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Joined: Tue Nov 16, 2010 9:36 am
Posts: 5
Once check the compression and pressure and can get good result...

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