liviob Posted October 13, 2011 Author Report Share Posted October 13, 2011 (edited) Now I am getting a headache! First Billy, now you! For a given altitude, a lowering of temps would create a higher air density, therefore requiering the airscrew opening to be reduced(or fuel screw increased) in an effort to attain the same mixture for the engine(same jets). You gotta ritchen the mix that the denser air has created. Sorry for the headache. Your right i got it backwards. Irregardless opening the air screw another 1/2 turn made the engine run smoother with the same old plug installed. So hopefully that was the problem. Edited October 13, 2011 by Liviob Quote Link to comment Share on other sites More sharing options...
liviob Posted October 13, 2011 Author Report Share Posted October 13, 2011 Jon must be reeling by now after a take at Billys rambling prose! There within, I find good and bad points. My basic farmboy take is simple, and does not disagree with some of his points. Firstly, IS the system optimized by the factory settings? Or is this simply a conservative reliable setting that may be used for the sake of whatever lack of problems. Engineers tend to build up to a point, then back down for reliability in productiion. Second , The range on preffered gap settings as stated by Lovio is quite wide. (theory still suggests that he can push the gap up under his lower density conditions, providing the mix is not too lean) Thirdly, Going along with the first statement, I will admit that I have been somewhat conservative in my personal experimentation, for some obvious reasons, yet the(my) results seem to be reliable and working(at .028 plug gap) so the system has thus far supported it without issue for several years now.. Within common ignition theory , one will find two common issues, gap and duration of fireing. Both provide better exposure to the combustion gass moving within the chamber as the mixture must be exposed to the electrical ionization to ignite it properly. The system will either reliably support the gap and or duration, or it will not, all mostly depending upon ultimate load imposed upon the arc. Throttle openings and mixtures come into play. Then we get into another potential issue here within system design, and to be honest, I do not really and totally know what we are dealing with. They call these things a digital CDI in some or most cases, although I must admit the fact that neither I or many have no idea just exactly what is in these little boxes that actually control things. Seems there is little out there, and although I would somewhat compare it all to a lawnmower with an electronic ignition, functonal testing seems nil via conventional means. The things are reported to have a timing curve to them, so they must be somehow manipulated by the electrics. As an example I use the Leonelly basic diagram used in the Sherco which suggests 2 charge coils and 3 hall effects to run it! Are they charging caps? Very possible. Now within all that, I may fathom it being true CDI, but being CDI in itself it is also limited to the spark dration limitations inherent in the system, and thusly there is a quick voltage dump through the primary coil and a resultant burn time of about 1 ms which is not altered by the demands of gap requirement, it is either achieved or not all in one quick shot by the capacitive dump. Ones gap being the last resort in achiving the best flamefront exposure possible, which should be open and exposed as you do not have a second chance here. I dont doubt that the ignition can support a .028 plug gap. I have seen the spark of this ignition system reliably jump a 1/4" gap, and Yes I am a little hessitant to set it there and forget about it for awhile. The Beta manual suggests .020-.024 plug gap. I believe i am correct in assuming the plug gap generates a certain amount of resistance in the electrical charges path to ground. With the larger gap creating more resistance I would think it would also be generating more heat somewhere in the ignition system which i have no way of monitering. Possibly in the coil or the generator? My concern is that the extra heat generated might damage or cause failure to some expensive part. I dont disagree with your thoughts i'm just being conservative about making changes of this kind. Quote Link to comment Share on other sites More sharing options...
outlaw dave Posted October 13, 2011 Report Share Posted October 13, 2011 Hi Liviob - We sell lots of Betas and one thing that we did have happen on a couple of 09 Evo 290's was the float valve was sticking, causing the engine to flood - we cured this by fitting a new valve. - The float level is critical on this carb, and you can see how to adjust it by clicking on the Beta UK website. We also take our bikes up into the 7,000ft altitude and they do not require any adjustments. Best Regards Outlaw Dave Quote Link to comment Share on other sites More sharing options...
b40rt Posted October 13, 2011 Report Share Posted October 13, 2011 Is it an air screw, or a petrol screw ? Quote Link to comment Share on other sites More sharing options...
liviob Posted October 13, 2011 Author Report Share Posted October 13, 2011 (edited) Thanks for the tip outlaw Dave. It's possible, but i dont think ther is a problem with the fuel needle valve and usually i dont have to adjust the air screw very often once summer or winter has set in but during the transition seasons air temps and humidity can widely vary throughout the day and combined with the three to four thousand foot altitude changes that can occur during a ride somtimes it becomes obvious that an air screw adjustment is necessary. I'm planning to ride a trial this weekend. I will take note of the engines peformance. Hopefully the issue hs been resolved. Edited October 13, 2011 by Liviob Quote Link to comment Share on other sites More sharing options...
liviob Posted October 13, 2011 Author Report Share Posted October 13, 2011 Is it an air screw, or a petrol screw ? Air screw. Quote Link to comment Share on other sites More sharing options...
billyt Posted October 13, 2011 Report Share Posted October 13, 2011 I'm planning to ride a trial this weekend. I will take note of the engines peformance. Hopefully the issue hs been resolved. Go kick some butt at the weekend ! Cheers BillyT Quote Link to comment Share on other sites More sharing options...
liviob Posted October 13, 2011 Author Report Share Posted October 13, 2011 (edited) He,he, Thanks BillyT. I'll certainly try. I dont know if you have ever rode Turkey Rock near Salida, Co. the same place they had the national last year, But a trials there is usually difficult and fun. Edited October 13, 2011 by Liviob Quote Link to comment Share on other sites More sharing options...
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