steve1979 Posted February 8, 2017 Report Share Posted February 8, 2017 I had considered this project pretty much finished. She has had everything replaced from new carb to full engine rebuild. All cables etc, seals. There is basically hardly any original left. She was starting great and she had new points, condenser and coil. Points were set to 1.8mm btdc at 0.35mm. I have had a few runs on her and she was lugging me around, all 15 stone of me. She does have a new 60cc barrel kit as the 50cc was badly worn and scored. Just recently a friend came over and asked "does it run"? I promptly went to start it and that's when the trouble began. It ran for about 30 seconds then fluttered out. Since then it won't start. Although she is getting a nice blue spark and after a few kicks the plug is soaked as though she has flooded. I suspected a intermittent spark from the ht lead so I replaced that this afternoon, but still it's a no go! Still sparking, still seems to be getting fuel. But even when you try and bump start it, it turns over with no joy then gives a little burp of life as though it would like to start but then nothing. I've invested a lot of time and money and effort into getting this up and running for my son but I really am left wondering what could be up with it. I'm going to strip the carb again, and re-check but if anyone has any suggestions it would be greatly appreciated. I'm assuming the TY50/60 now, shares the same point gaps etc as the 80cc thanks steven Quote Link to comment Share on other sites More sharing options...
stan wellback Posted February 8, 2017 Report Share Posted February 8, 2017 check flywheel woodruff key. Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 8, 2017 Author Report Share Posted February 8, 2017 Ah, now there's a possibility. I replaced the woodruff key when I rebuilt but I did have the flywheel off again to recheck something and I reused the new one, I'm thinking that should have been ok, and I torqued the flywheel to the correct torque, although on a website for the ty there are two different torque settings if I remember correctly. But I think I'll need to double check the woodruff. Thanks for the suggestion:) Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 8, 2017 Author Report Share Posted February 8, 2017 (edited) On the ty trials shop page it has tips as well as supplying the part, for the woodruff key it says the flywheel must be torqued to 25-29lbs/ft but for the (special) nut for the flywheel they state it must be torqued to 50lbs/ft otherwise the key will shear, we'll both times I have torqued the flywheel to 29lbs/ft as I didn't want to over stress the threads as they claim to have two different torque values. I'm wondering if it has sheared the key. And if it has what state the end of the crank will be now. On the the weebly spec page for the ty 80 it states the flywheel should be 3.5 -4.0 kg-m which is 25-29 lbs/ft so I'm unsure why the trials shop has 50 lbs/ft unless it's for that particular (special) nut? I'm not sure if that nut is a standard nut or like it says a special nut, it claims it's long to stop it stripping the threads but I can't remember the nut on the end of my crank looking extra long. Edited February 8, 2017 by steve1979 Adding information Quote Link to comment Share on other sites More sharing options...
dadof2 Posted February 9, 2017 Report Share Posted February 9, 2017 On a TY80 I fitted brand new points that turned out to be faulty. Intermittent spark. The points had resistance where they were riveted together. Faulty source coils or condenser can also give intermittent running with symptoms you describe. Also known fault at spade connector under tank where HT coil connects to giove problems. Quote Link to comment Share on other sites More sharing options...
lineaway Posted February 9, 2017 Report Share Posted February 9, 2017 30 seconds can actually be a long time. You might pull off the pipe and take a look at the piston. That is after checking the key. Quote Link to comment Share on other sites More sharing options...
tydan Posted February 9, 2017 Report Share Posted February 9, 2017 Steve I recently had the exact same symptoms that you have described. Put the engine back together timed it up, into the frame and started second or third kick. A week or so later do some double checks I adjusted the points gap etc. Wondered why it wouldn't start next time around. Timing was out, if your woodruff key is OK check your timing again. Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 9, 2017 Author Report Share Posted February 9, 2017 Hi guys, thanks to you all for suggestions. Tonight I pulled the flywheel, but the woodruff key is intact and sitting where it should be. Visually I can't see any issues with the points or condenser as there new anyway but that's not to say for some reason they have failed. Just out of interest I measured the depth of the flywheel nut and it is 10mm so I wouldn't class that as extra long and I'll re torque it back to 29lb. Like Steve says I'll need to double check the timing. It's a bit tricky as I'm doing it by dropping the stem of a set of digital calipers and measuring the depth from plug hole then adding on the 1.8mm and then rotating the piston back to that point. I don't have one of those gauges that screw into the plug hole so I'm hoping my method is relatively accurate. I will be pulling the carb and reed block off and triple checking the carb for debris and making sure the reeds are not stuck. While the reed block is off I can have a squint at the piston, but she was running fine until she decided to get fussy. I'll recheck the wiring to going to the coil as mentioned but I renewed it when I replaced everything. I'll be working on her tomorrow and I'll keep you all updated with my findings, "if I do find anything" Quote Link to comment Share on other sites More sharing options...
guy53 Posted February 10, 2017 Report Share Posted February 10, 2017 Kill switch ? Guy Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 10, 2017 Author Report Share Posted February 10, 2017 The kill switch is new, but again who's to say it isn't faulty. She is sparking tho when the plug is out, and sitting on the head. I'm going to bypass the kill switch for now just in case. Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted February 10, 2017 Report Share Posted February 10, 2017 Mark the flywheel and engine casings with your TDC and 1.8mm BTDC then use a strobe to check. Less fiddling about than if not using a screw in gauge. Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 10, 2017 Author Report Share Posted February 10, 2017 I checked and cleaned the points, cleaned them with emery even though there new, I'm not sure how to check with the strobe, I'm relatively good with the spanners but these points appear to be a learning curve. I appreciate the help everyone is giving but bear with me. I refitted the flywheel and rechecked the point gap. I butchered a spark plug and bored it out to take a aluminium rod which was a loose slide fit. I rotated the flywheel till tdc then put a very fine mark on the rod, using my digital caliper I added 1.8 to that which should give me in the park setting. Set the points to .35. Put in the spark plug and it was a weak purple spark. Took off the kill switch wire bypassed and reconnected the coil straight from the stator and it got no spark at all, so I put a light tester as in the screw driver with the crocodile clip attached, direct from the yellow wire coming from the stator (primary coil?) and spun the engine with a battery drill and it lit up as in power coming from stator. Reconnect to main coil and no spark? So I'm wondering if the main coil is faulty ( it's also new). Quote Link to comment Share on other sites More sharing options...
stan wellback Posted February 10, 2017 Report Share Posted February 10, 2017 did you paint anything whilst it was apart?. you had a kill button and a weak spark, removed the button, no spark. buttons work by going to ground. have you painted over earthing points? try eathing coil to engine. ps, sorry for leading you up the woodruff key path! Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 10, 2017 Author Report Share Posted February 10, 2017 A step in the right direction! Cutting a long afternoon short, I found the ngk 6 plug wasn't sparking at all, but when I took the plug cap off and put the ht lead to the head it was sparking fine. So cap back on and tried a plug, not the right plug but a good plug, and hey presto nice blue spark. Tried the basically brand new 6 plug and nothing, when it was sparking a weak purple before it must've been on it's way out. Luckily I kept the original no:7 plug that was in her before and tried that, ancient plug...but it was sparking blue. Reassembled the bike and she fired first kick. However she would not take revs at all. She ran for a minute or two and while I was feathering the throttle to get her revs up she stalled. Wouldn't restart at all. Took the plug out and it was as black as could be with soot. I cleaned the plug, checked it had a good spark and I put it back in, tried it but no joy, took it out and it was soaking wet so probably a bit flooded, I have been messing with settings trying to get her running so the carb etc is probably way out. At least it's been running. So I'm going to assume the coil, etc etc is fine. First time I've come across a plug completely failing, especially a new one, I'll be replacing it with a no:7. I'll need to be asking questions about the carb setting etc. Would you think the settings will be the same for the 50 as it is for the 80. Many thanks to you all for your help so far, it's been very much appreciated. Quote Link to comment Share on other sites More sharing options...
steve1979 Posted February 10, 2017 Author Report Share Posted February 10, 2017 (edited) 2 hours ago, stan wellback said: did you paint anything whilst it was apart?. you had a kill button and a weak spark, removed the button, no spark. buttons work by going to ground. have you painted over earthing points? try eathing coil to engine. ps, sorry for leading you up the woodruff key path! Hi Stan, not a problem about the woodruff, worth a check. I needed to take the flywheel off anyway to check the wires I soldered onto the condenser. My lesson to myself is to not assume a brand new plug is working as it should. I did state in my original post it had a good blue spark, that must have been while it was out, and under compression it was failing, until now it's totally failed. Edited February 10, 2017 by steve1979 Quote Link to comment Share on other sites More sharing options...
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