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Post by blackbag on Jun 9, 2014 12:22:28 GMT -5
So I swapped out the 49cc and upgraded to an 83 (51.5mm) cylinder only kept the stock head and now even my high torque starter can barely turn it over so I'm stuck again with no electric start. It will start with kick but its a major pain in the arse. What options do I have to lower my compression to get electric start going? From what I've derived from here so far.
1. Tear the whole thing down and add a gasket (I'm assuming base not head)
2. Get a better battery that will kick out over 200CCA
3. Order a big valve head
Am I missing anything? I have an A9 cam on the way from scrappy. Will that increase or decrease compression? I'm guessing my compression is probably somewhere in the 200 range.
Thanks!
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Post by JerryScript on Jun 9, 2014 15:25:52 GMT -5
The generally accepted method is to use an extra base gasket, and that's also cheapest. A big valve head will probably solve the issue as well, but it will only improve performance if it is ported well (it will improve a little without porting, but a good port job makes all the difference). An A9 cam will not make any difference on compression.
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Post by blackbag on Jun 9, 2014 15:34:59 GMT -5
Has anyone ever measured drop of compression between using 1 and 2 gaskets? or changing to big valve heads?
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Post by jerseyboy on Jun 9, 2014 16:04:47 GMT -5
High torque starter and starter clutch might help too..
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Post by jerseyboy on Jun 9, 2014 16:06:14 GMT -5
Whoops,,sorry I just read you already have a starter...
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Post by geh3333 on Jun 9, 2014 16:25:26 GMT -5
How's your battery ? A bad battery will cause problems. Jump your scoot from a car and see how it turns over . It's worth a shot .
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Post by blackbag on Jun 9, 2014 16:33:09 GMT -5
Battery is only a month old. Rated at 120 CCA. I'm thinking about getting a 220 like Milsc has reported worked for his high compression issue. It worked great yesterday cranking over the stock cylinder, now it seems to struggle moving it 1 stroke.
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Post by blackbag on Jun 9, 2014 16:37:23 GMT -5
Geh3333, You had to choose my topic to make post number 666 for you. Hope thats not a bad omen.  |
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Post by geh3333 on Jun 9, 2014 16:39:39 GMT -5
Sh-t I didn't even notice ! I better post another , wait I am right now .
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Post by blackbag on Jun 9, 2014 16:55:18 GMT -5
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Post by jjoshua20213 on Jun 9, 2014 17:21:26 GMT -5
Someone on this forum told to they just bought a cdi that rerards the timing at startup so compression is less and easier to start. I think is was the gold casoli dci
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Post by JerryScript on Jun 9, 2014 17:38:41 GMT -5
There are several gold Casoli CDIs. The advancing angle (not advanced but advancing) CDI that tvnacman sells is the one that is retarded at startup, and advances as the RPMs increase. It doesn't do anything to the amount of compression, the retarded startup helps prevent kickback, which is due to a combo of low RPMs and the timing being too advanced, not compression. Once you are at or above idle RPM, the CDI advances the timing so that the firing occurs a bit earlier, allowing for more compression of the combustion event.
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Post by blackbag on Jun 10, 2014 3:18:17 GMT -5
ARGH!!!! Hooked up a 220CCA battery and still no go. Tore it down and put the extra base gasket in and turned it over by hand a few times since it's late and dont want to wake the neighbors. Compression still feels really high. I'll hook the battery back up in the morning and see how it goes but it really doesn't feel much different.  |
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Post by jerseyboy on Jun 10, 2014 6:11:49 GMT -5
Na,,that little gasket aint gonna do much if your compression is that high...maybe the more you run it the better it will get??
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Post by ramblinman on Jun 10, 2014 7:31:53 GMT -5
ARGH!!!! Hooked up a 220CCA battery and still no go. Tore it down and put the extra base gasket in and turned it over by hand a few times since it's late and dont want to wake the neighbors. Compression still feels really high. I'll hook the battery back up in the morning and see how it goes but it really doesn't feel much different. iicr millsc also had to upgrade the wire to get his to work. |
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