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Old 07-11-2005, 03:42 PM
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Default Vintage 2-stroke ignition headache. Got relief?

Greetings board.
I have a 1973 Yamaha SC-500 Scrambler. Single cylnder, 500cc's, oil injection removed. When I got the bike it had no fire. I found the ignition component resistant values in the motor manual and everything ohmed out ok. Of course I don't have the Yamaha "pocket tester" so couldn't check the CDI. OK, on the the present. I have replaced every<U></U> component of the ignition, and now I have fire. The problem is, the engine wants to run backwards. My compression relief is working, now, but the engine will only fire a few revolutions in the forward direction, then dies. If it kicks backwards, it'll start and idle and rev-up just like it should. I have followed the manual's spec's for timing, and am using a dial indicator, and have been forwards and backwards of the spec position, and the results are the same. There it is, sorry for the length, but I'd be glad to elaborate further, and appreciate any comments.
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Old 07-18-2005, 03:13 PM
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I entertained my father by firing up a freshly restored '73 RD350 several years ago, only to let out the clutch and ride backwards down the driveway... it's definitely the timing. Continue to advance/retard until you find the point where it will run forward, you can fine tune it from there. I too was using a dial indicator, and a Clymer manual, but found that I had go by feel more than the spec.
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Old 07-18-2005, 07:11 PM
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Thanks for the reply. I have this post on three different websites, and you are the second to reply and the first that provides any info. I have been trying to move the timeing around, even drilled new holes in the stator plate to let me get way out of spec, but haven't found that sweet-spot yet. Thanks for your reply.
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Old 07-20-2005, 05:23 AM
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Your'e a bunch of no brainers that read magazines and buy new products that you don't know if they will even increase your bike's performance. I figured out my problem via research and common sense............geez
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Old 07-20-2005, 03:41 PM
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Default Re: (macar55)

Wow, that seems a bit harsh, don't you think? You got a reply that by your own admission gets at the heart of your problem, and then you blast the help you got? Maybe that's why no one else on any other board answered you!
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Old 07-25-2005, 04:54 AM
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Default Re: (Gerg)

No actually were a bunch of brainers that come to a forum and post to find and help each other with problems. I think you responded to the wrong post.
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Old 07-25-2005, 05:50 AM
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Default Re: (mulisha00)

funny
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Old 07-26-2005, 06:12 PM
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Default Re: (Gerg)

so, are you going to enlighten us with what you did to make it go forward? or not.
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