steve1979 Posted February 10, 2017 Author Report Share Posted February 10, 2017 still not sorted, really frustrated. Sparks when it feels like it. Even the plug I thought was duff is now sparking like lightning show, no idea now. Still won't start. Going to have to leave it before I lose it! Quote Link to comment Share on other sites More sharing options...
b40rt Posted February 10, 2017 Report Share Posted February 10, 2017 Change the condensor. Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 10, 2017 Author Report Share Posted February 10, 2017 Ok, I'll get another and try it. Frustrating when I was running so good, the few times I was on it. 1 Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 11, 2017 Author Report Share Posted February 11, 2017 Ha, you couldn't make this up. Went to the sons ty this morning, blue spark, put plug in and it starts first kick. Running great for about 1-2 minutes then nothing like you've hit the kill switch. Pull plug and no spark. So put a tester on the end of the source coil lead, put in gear and spin over and nothing, so like b40rt says must be the condenser. Best bit is though, a friend comes over with his new montesa, so we go out for a play, him on his montesa and me on my gas gas. We've been out an hr or so and we swap bikes. Ten minutes later I notice him trying to start mine. I ride over and he says it just stopped, I try and it fires and runs for a few seconds but won't Rev, so back to mine, pull the plug and surprise surprise no spark!! Well a poor orange one. I had a new spare plug, put that one in, way hay blue spark! Up she fires, and off we go again. What is it with me and electrics lol, I think I need to stick to pedal power. Quote Link to comment Share on other sites More sharing options...
jbird Posted February 11, 2017 Report Share Posted February 11, 2017 Hey Steve,. I rebuilt an engine years ago and put to much oil in the crank thinking the bearings were new and should have some pre lubrication . it would foul plugs for quite some time before the crank got clear of the oil. Sounds similar to way your runs. Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 12, 2017 Author Report Share Posted February 12, 2017 Hi jbird, it's not sparking at all now. I've put a tester lamp between the source coil and earth and getting zero. I haven't got the multimeter on it yet, but I think there's no point. I'll need to order another tune up kit. I suspect the condenser has completely shorted or something, like b40rt mentioned. But just rule out a loose connection on the points I may as well replace them too. I'm wondering if condensers are generally universal and I could get say a heavier made one and mount it else where. But for convenience I'll probably just get the standard condenser. Just fingers crossed it's not the actual windings themselves that's gone. Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 17, 2017 Author Report Share Posted February 17, 2017 (edited) Ok, finally got her running. New condenser, ht spark plug cap, spark plug. She desperately needs tuning, but I'm wondering if someone can clarify my method of setting the timing, I set the timing how I think it should have been. It started second kick and was idling but could not take any throttle at all!! So I just tweeked the points in either direction and the first time I was that far off it wouldn't start, so a tweet in the other direction and voila!! She's running and fairly crisp of the throttle, but a tiny flat spot, so my "guess work" on the points must be in the ball park but will need setting correctly. So here's how I set the points, if anyone can correct me if I'm wrong it would be much appreciated. 1) find TDC 2) rotate flywheel clockwise until 1.8 BTDC is found 3) wedge flywheel at this point and set points to 0.014in or 0.35. Is this correct or am I doing it wrong? cheers Edit, just found the online manual guide someone has posted, so I think I have been doing it slightly wrong, I need to get the points to just start to open at 1.8 btdc, and the gap setting is not really adjustable it just needs to be between 0.3 and 0.4 and if it falls out of that spec then the points are worn. Would this be the correct technique? I'm probably making something simple, complicated. Edited February 17, 2017 by steve1979 Quote Link to comment Share on other sites More sharing options...
feetupfun Posted February 17, 2017 Report Share Posted February 17, 2017 5 hours ago, steve1979 said: Edit, just found the online manual guide someone has posted, so I think I have been doing it slightly wrong, I need to get the points to just start to open at 1.8 btdc, and the gap setting is not really adjustable it just needs to be between 0.3 and 0.4 and if it falls out of that spec then the points are worn. Would this be the correct technique? I'm probably making something simple, complicated. Yes you were complicating it. The piston position when the points open is critical. The 0.3 to 0.4 gap is not critical. Just to explain why the Yamaha does not have an adjustable (slotted holes) backing plate. It is to make sure that the magnet in the flywheel is in the correct spot relative to the stator coil when the points open, to maximise the spark energy at the spark plug. Some other bikes are less sensitive to having the magnet position exactly right and have slotted holes so you can change the timing without changing the points gap. Working out exactly when the points are opening can be done by just looking at them with a torch (least accurate), inserting some very thin paper (roll-your-own cigarette paper), using a battery and low voltage light bulb across the points or using a timing buzzer across the points. The light bulb and buzzer methods give the best accuracy. Because points ignitions sometimes have problems with sparking between the points (condenser failure) or mechanical problems with the points mechanism, it is a good idea to also check the spark timing with the engine running by using a strobe light that is triggered by the spark (timing light method). If the points and condenser are working properly, the spark timing should not change as RPM changes so if you see it move using the strobe, you will know you have a problem 2 Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 18, 2017 Author Report Share Posted February 18, 2017 What a very detailed explanation, that makes sense to me! Thankyou very much for taking the time to write that up, very much appreciated. I've taken what you said onboard and got her timed up today. Now she's running a beauty. Couple of small jobs to do and then she's ready to hand over to my son for his 6th birthday. Thanks again to all who have contributed on this thread. 1 Quote Link to comment Share on other sites More sharing options...
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