cunpr Posted March 1, 2011 Report Share Posted March 1, 2011 Dear All, I'm now at the stage of putting my Frontera back together. I've got one of the Electrex electronic units and am too embarassed to ring them yet again as to how to set up the timing! I have their info sheet but I still can't work it out. The Bultaco manual says static timing should be 2.4-2.6 mm BTDC, that's static timing. The Electrex unit automatically advances above 4,000 rpm. The Electrex sheet says that 2.4mm BTDC equates to 22:30' degrees BTDC on the flywheel and suggests you use a strobe to set the engine (i.e. when running) to this. So engine running set to 2.4 mm BTDC, engine static 2.4mm BTDC. SO where's teh advance gone? DO they mean that you run the engine at 4,000 and when the strobe is indicating 22:30' BTDC that that is the equivalent of a static setting of 2.4 mm BTDC? I suppose it boils down to; is the Electrex unit set with a strobe when idling or when revving above 4,000 rpm? Apologies again if I'm being a bit dim. Regards Paul CUndy Quote Link to comment Share on other sites More sharing options...
copemech Posted March 1, 2011 Report Share Posted March 1, 2011 Set with the strobe at idle because it advances when revved beyond 4k rpm. Either way, you need to accurately establish TDC as a referance. Do you know how to find that? Quote Link to comment Share on other sites More sharing options...
triple_x Posted March 1, 2011 Report Share Posted March 1, 2011 (edited) Hi When I got my Electrex set for the Sherpa I faced the same problem. However by installing it as per instructions set screw @2 0'clock (top R/H) to the mid point of the slot it ran ok. Being a bit sad i measured the O/D of the flywheel multiplied it by 3 1/7 (3.1428)which gave the circumference. I simply divided it by 360 (= degrees in a full circle). That gave me the amount of rotation for 1 degree. Multiply that by 24(or what advance you need)which give you the advance rotation. Set piston at TDC and fix a pointer anywhere convenient on the crankcase, mark the flywheel with a felt tip marker and scribe a line. That is your TDC mark. Then measure to amount of rotation for 24 degress (or what you prefer) scribe that dimension anti clockwise from the tdc. Rotate the flywheel to the pointer and you piston should have lowered by the correct amount(use a VERNIER GUAGE to check). The annoying part is that you have reassemble the cover, start the engine, remove the cover and check the timing with the engine running. As said in a previous post at 4k rpm the timing should advance to the correct timing position Good luck, it sounds more difficult than it is. It worked for me! Martin Edited March 1, 2011 by Triple_X Quote Link to comment Share on other sites More sharing options...
insultaco Posted March 1, 2011 Report Share Posted March 1, 2011 Hello all I ordered a new ignition (SK-154) for my M159 325cc Sherpa yesterday from Electrex, but they didn't bother sending it till today, despite being assured it would be here today. They didn't bother to ring me either, just to let me know not to waste a day waiting for them not to turn up! I hope the ignition is worth the wait, because its not very good service from them. Spend the extra Quote Link to comment Share on other sites More sharing options...
cunpr Posted March 1, 2011 Author Report Share Posted March 1, 2011 (edited) Set with the strobe at idle because it advances when revved beyond 4k rpm. Either way, you need to accurately establish TDC as a referance. Do you know how to find that? Dear Copemec, Thanks, so the electrex unit is set to simulate the static timing when at idle but advances when reved. That's what I will do. I have a TDC dial gauge so yes I can measure that and yes I know where to screw it....... Dear Triple X thanks also, thats exactly what I did when I set the Electrex unit up on my 340 Sherpa, bloody laboriuos and again the instructions didn't really help. Its a steep learning curve, after I'd first done it it ran like a bloody pig and the strobe was all over teh place like saturday night fever, eventually worked out it was due to my having a 6 pole magnet flywheel when the Electrex unit is designed to be triggered by a 4 pole flywheel, try imagining how to work that one out "logically"! Eventually got it set but after I've done the Frontera I'm going to go back and apply the same logic to the Sherpa, set at idle to Electrex degrees BTDC and then allow it to advance beyond when running. It does seem that Electrex would benefit from having someone go through their instructions with a "plain english" hat on. Regards Paul C Edited March 1, 2011 by cunpr Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted March 1, 2011 Report Share Posted March 1, 2011 When fitted and running properly was the Electrex system worth the hassle over the points system, was it a worthwhile improvement? Quote Link to comment Share on other sites More sharing options...
pschrauber Posted March 1, 2011 Report Share Posted March 1, 2011 When fitted and running properly was the Electrex system worth the hassle over the points system, was it a worthwhile improvement? Would be interesting to hear any experience storys or data to me too, I have been told that it is not so much necessary, because the engne is more running at lower rpm? OK there are the point, something to check here and there, but beside of checking points and probably exchange them ... ??? Quote Link to comment Share on other sites More sharing options...
triple_x Posted March 1, 2011 Report Share Posted March 1, 2011 Hi I am very pleased with my Electrex set up. After all the faffing about is was well worth it. Of interest was that after fiddling with a strobe and getting it spot on it was back in the position the instuctions advised. I think the confusion is that points are static timing, Electrex advances to the optimum by 13 degrees (I think) and it is this feature that makes the power deliver so smooth and tractible. Well worth the money. Martin 1 Quote Link to comment Share on other sites More sharing options...
pschrauber Posted March 1, 2011 Report Share Posted March 1, 2011 Hi I am very pleased with my Electrex set up. After all the faffing about is was well worth it. Of interest was that after fiddling with a strobe and getting it spot on it was back in the position the instuctions advised. I think the confusion is that points are static timing, Electrex advances to the optimum by 13 degrees (I think) and it is this feature that makes the power deliver so smooth and tractible. Well worth the money. Martin OK, this is an advantage, with the points you have only one timing! Three question to the electrex ignition is it only the stator you change? or the complete ignition unit with stator and rotor? are their also a power supply added for lights f.e. ? Quote Link to comment Share on other sites More sharing options...
triple_x Posted March 2, 2011 Report Share Posted March 2, 2011 OK, this is an advantage, with the points you have only one timing! Three question to the electrex ignition is it only the stator you change? or the complete ignition unit with stator and rotor? are their also a power supply added for lights f.e. ? Just the stator plate, the flywheel remains. Replace the original coil and condensor with the control box under the tank. Really easy to fit. Regards Martin Quote Link to comment Share on other sites More sharing options...
cunpr Posted March 2, 2011 Author Report Share Posted March 2, 2011 OK, this is an advantage, with the points you have only one timing! Three question to the electrex ignition is it only the stator you change? or the complete ignition unit with stator and rotor? are their also a power supply added for lights f.e. ? Depends, my Sherpa it was only the stator and ignition only. The Frontera kit has a new flywheel as well as the stator and I asked them to put a lighting coil on it as well which they did. Speak to Peter, basically they can build one to your spec. the kits are beautifully machined, finished and packed and mine both arived in days and everything fitted straight out of the box, its just the instructiosn I can't sort out! Quote Link to comment Share on other sites More sharing options...
cunpr Posted March 2, 2011 Author Report Share Posted March 2, 2011 Hi I am very pleased with my Electrex set up. After all the faffing about is was well worth it. Of interest was that after fiddling with a strobe and getting it spot on it was back in the position the instuctions advised. I think the confusion is that points are static timing, Electrex advances to the optimum by 13 degrees (I think) and it is this feature that makes the power deliver so smooth and tractible. Well worth the money. Martin Dear All, OK just spoken to them again and with the wisdom from the replies above and clarity having googled the theory of ignition advance timing here is the answer. The electrex system advances the timing by 12-13' up to approx 3,000 rpm BUT beyond approx 4,000 rpm it then retards it slightly. So the advance curve has a peak. The system is supposed to be set with the strobe indicating spark at 22-23' BTDC at the peak of the advance curve, i.e. about 3,500 rpm. When its set like that the timing will be retarded at idle to about 10' BTDC which makes it easier to start and less likely to break your ankle. So the way to do it is to get it running, watch the advance reach maximum on the strobe as the engine speed increases and then set it to the 22' BTDC with the advance at the peak of the curve. Hope that helps clear it all up. Regards Paul Cundy Quote Link to comment Share on other sites More sharing options...
insultaco Posted March 2, 2011 Report Share Posted March 2, 2011 (edited) Hi I have fitted my new Electrex system today and it starts a lot easier than it did, but I'm also a little confused about the timing. I have two tipex marks on the rotor, one at 3.0mm BTDC and one at 2.8mm BTDC, the bike idles with the strobe light right in the middle of the two. Is this the same as 10' BTDC or do I need to mark the 23' and 10' marks and see where they lie with the strobe on them as the rev's rise and fall? Do I need a rev counter for this, or do I just look for the strobe to move round the rotor and peak at 23' as the rev's rise and pass 3-4k rpm? Cheers Mick (The system is fitted to an M159 325 Sherpa with standard setting of 2.8-3.0mm BTDC) Edited March 2, 2011 by insultaco Quote Link to comment Share on other sites More sharing options...
motovita Posted March 2, 2011 Report Share Posted March 2, 2011 Can we hear some specific results from riders who have run their Trials bikes with both ignitions? What are the perceived differences? Wider powerband? Top end power? differences in starting? ??? Was it worth it? Quote Link to comment Share on other sites More sharing options...
cunpr Posted March 2, 2011 Author Report Share Posted March 2, 2011 Hi I have fitted my new Electrex system today and it starts a lot easier than it did, but I'm also a little confused about the timing. I have two tipex marks on the rotor, one at 3.0mm BTDC and one at 2.8mm BTDC, the bike idles with the strobe light right in the middle of the two. Is this the same as 10' BTDC or do I need to mark the 23' and 10' marks and see where they lie with the strobe on them as the rev's rise and fall? Do I need a rev counter for this, or do I just look for the strobe to move round the rotor and peak at 23' as the rev's rise and pass 3-4k rpm? Cheers Mick (The system is fitted to an M159 325 Sherpa with standard setting of 2.8-3.0mm BTDC) As I understand it you watch the strobe move round the flywheel, as the revs rise it will move round until it reaches a maximum advance and then as the revs rise furtehr to flat out it will move back again. you need to adjust the revs so that it is at the peak maximum advance (which will not be flat out) and then set the stator so that the strobe is on the 22' BTDC mark. Then when idling the strobe should be around teh 10' mark. It sounds as if you are pretty close anyway. Regards Paul C Quote Link to comment Share on other sites More sharing options...
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