Codyonkwaj Posted November 14, 2019 Report Share Posted November 14, 2019 I’m having some problems with my spark plugs backing out. 10mil 465 cheetah cub on vp110 with 23cc domes 150comp, in both cylinders. Timing is advanced +5 with a dynatech timing adjuster thing. Shearer pipes. Jetting is 195 mains in 39mm carbs. Weird thing is that they only back out at the dunes at sea level. 1500ft above sea level where i live they’re fine. So idk what’s up. Any advice would help Quote Link to comment Share on other sites More sharing options...
Keno Posted November 14, 2019 Report Share Posted November 14, 2019 Plugs backing out is detonation. You are having it at sea level as your jetting is probably just lean enough (at sea level) to allow for detonation. You can either Jet up, pull back timing, or decrease compression. 1 Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted November 14, 2019 Report Share Posted November 14, 2019 I always jet up a size or two for the sand. puts more load on the motor, I also run a 9 series plug in the sand. Quote Link to comment Share on other sites More sharing options...
Keno Posted November 15, 2019 Report Share Posted November 15, 2019 Also curious what +5 with a dynatek is? As it is a programmable that could be anything. Also +5 on a dynatek's "stock" curve is actually more than a stock cdi's +5. Quote Link to comment Share on other sites More sharing options...
SKEETER Posted November 15, 2019 Report Share Posted November 15, 2019 Get a trinity plug lock , itll solve the detonation issues. 1 Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted November 15, 2019 Report Share Posted November 15, 2019 Just timing on the ignition? No aftermarket plate under the Stator? Quote Link to comment Share on other sites More sharing options...
Codyonkwaj Posted November 16, 2019 Author Report Share Posted November 16, 2019 On 11/14/2019 at 5:27 PM, Keno said: Also curious what +5 with a dynatek is? As it is a programmable that could be anything. Also +5 on a dynatek's "stock" curve is actually more than a stock cdi's +5. I just meant my actual timing plate is at +5. I also have dynatech curve adjuster I guess is what you would call it. timing advances based on RPM. On curve 3 anything above 6k it’ll add an additional 3 degrees of timing. At least this is what I understand it does. Quote Link to comment Share on other sites More sharing options...
Codyonkwaj Posted November 16, 2019 Author Report Share Posted November 16, 2019 On 11/14/2019 at 8:12 PM, trickedcarbine said: Just timing on the ignition? No aftermarket plate under the Stator? No sorry, what I meant is, my timing plate is advanced +5. I also have the dynatech which advances timing based on rpm Quote Link to comment Share on other sites More sharing options...
Codyonkwaj Posted November 16, 2019 Author Report Share Posted November 16, 2019 On 11/14/2019 at 5:27 PM, Keno said: Also curious what +5 with a dynatek is? As it is a programmable that could be anything. Also +5 on a dynatek's "stock" curve is actually more than a stock cdi's +5. http://www.dynaonline.com/skins/downloads/instruct/DFS7-1.pdf Quote Link to comment Share on other sites More sharing options...
Keno Posted November 16, 2019 Report Share Posted November 16, 2019 Edit: New chart since it sounds like you are running curve 3. I guess my point is to get the programming cable so you can keep timing down low and pull back up top. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted November 17, 2019 Report Share Posted November 17, 2019 On 11/16/2019 at 9:11 AM, Codyonkwaj said: No sorry, what I meant is, my timing plate is advanced +5. I also have the dynatech which advances timing based on rpm Exactly why I asked. That’s where your issue is. To much timing. Put the plate at 0 and let the Dyna do it’s thing. Or make sure the Dyna is programmed to accommodate the plate. Quote Link to comment Share on other sites More sharing options...
Tedder Posted November 18, 2019 Report Share Posted November 18, 2019 Tricked is right on. Dyna curve 3 plus 5* on the plate is way to aggressive. 1 Quote Link to comment Share on other sites More sharing options...
Codyonkwaj Posted November 21, 2019 Author Report Share Posted November 21, 2019 On 11/16/2019 at 8:55 AM, Keno said: Edit: New chart since it sounds like you are running curve 3. I guess my point is to get the programming cable so you can keep timing down low and pull back up top. So I have some bad news. Was out testing it this weekend. Changed the mains to 220 and it seemed to run much better. Unfortunately, a bit of the porcelain part of the spark plug broke off and seized the motor up. Full pinned in 5th. Locked up. Just stopped running. Got it to free up after kicking it for a bit. (Shouldn’t have done that in hindsight) piston and dome are like very rough sandpaper. And the cylinder doesn’t look too hot either. Any ideas. Sorry about the poor quality. They won’t let me upload anything over 53k Quote Link to comment Share on other sites More sharing options...
Tedder Posted November 21, 2019 Report Share Posted November 21, 2019 Ouch, The shattered porcelain is self inflicted detonation. Been there myself once when pushing the envelope on my alcohol tuning. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted November 21, 2019 Report Share Posted November 21, 2019 Ideas? See above. Way way way to much timing. Slap it back together and send it again. We’ll be here when you’re ready to keep it in one piece. Quote Link to comment Share on other sites More sharing options...
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