f1springy Posted January 7, 2008 Share Posted January 7, 2008 Hi, My daughters 2004 TZR50 was running fine then she said made a strange noise then stopped, maybe pinking by her description. Since then we can not start it. It turns over fine, I have checked the piston and rings and all are in good condition as is the compression. Cleaned the carb. There is fuel getting to the plug and I have fitted a new plug. The only thing I can think of is that the spark when checking it is a little irregular, jumping around the electrode not in a constant place? I am now at a lose to know what to do? Any help would be much appreciated. Link to comment Share on other sites More sharing options...
yoda Posted January 7, 2008 Share Posted January 7, 2008 Hi, My daughters 2004 TZR50 was running fine then she said made a strange noise then stopped, maybe pinking by her description. Since then we can not start it. It turns over fine, I have checked the piston and rings and all are in good condition as is the compression. Cleaned the carb. There is fuel getting to the plug and I have fitted a new plug. The only thing I can think of is that the spark when checking it is a little irregular, jumping around the electrode not in a constant place? I am now at a lose to know what to do? Any help would be much appreciated. Could have been a partial siezure. These free off when cold so will turn over again. The sparking is normal and is just taking the closests high spots off. You might have a weak spark that is not firing under compression so test the rest of the circuit. Link to comment Share on other sites More sharing options...
f1springy Posted January 7, 2008 Author Share Posted January 7, 2008 Hi, I did have the barrel off and all looked very good, no scoring or anything. The 2 stroke oil is topped up by myself, standard exhaust and jets so no tuning. Can you tell me how to check the rest of the circuit, would I need to borrow a multimetre from work and if so do you know what reading I should get. Also I guess I need to check back from the plug cap to the CDi unit? Link to comment Share on other sites More sharing options...
yoda Posted January 7, 2008 Share Posted January 7, 2008 I cannot help with the ignition electrics, as I do not have a manual for them but one thing you can easily check with a multimeter is continuity. You need to check from the centre electrode of the spark plug, when connected to the lead, to the outer of the lead. If there is any electrical connection at all, change the plug lead as your losing sparking voltage. This can also be intermittant so wiggle the lead to see if there is any difference. Link to comment Share on other sites More sharing options...
f1springy Posted January 8, 2008 Author Share Posted January 8, 2008 Thanks for your help I will try this at the weekend when I have time. Appriciate the help. Regards Rick Link to comment Share on other sites More sharing options...
fosdyke Posted January 10, 2008 Share Posted January 10, 2008 Hi, My daughters 2004 TZR50 was running fine then she said made a strange noise then stopped, maybe pinking by her description. Since then we can not start it. It turns over fine, I have checked the piston and rings and all are in good condition as is the compression. Cleaned the carb. There is fuel getting to the plug and I have fitted a new plug. The only thing I can think of is that the spark when checking it is a little irregular, jumping around the electrode not in a constant place? I am now at a lose to know what to do? Any help would be much appreciated. Hi Just a thought............this could be a timing issue, not familiar with the TZR50, but if it is similar to other 2 stroke singles with a magneto system you could have a broken woodruff key which would put the ignition timing out. A quick check would be to take out the spark plug, take off the magneto cover then using a large allen key check when the piston comes to TDC and then look at the points or the magnet if you have CDI unit. Rotate the flywheel back and forth and check to see if if the spark is created fractionally before the piston comes to TDC. If the timing is out then this would account for the bike appearing ok but not starting - I have worn out my leg a few times vainly trying to start a bike with a timing problem!! New woodruff key costs around £1 or less. Hope this helps. Link to comment Share on other sites More sharing options...
f1springy Posted January 11, 2008 Author Share Posted January 11, 2008 That sounds very promising! I will have a look tomorrow and let you know the out come. Thank you very much for your help, much appreciated. Link to comment Share on other sites More sharing options...
yoda Posted January 11, 2008 Share Posted January 11, 2008 It might not be so straight forward to look at. You need to check for any play between the the rotor and the shaft. Any play change the key. Link to comment Share on other sites More sharing options...
f1springy Posted January 14, 2008 Author Share Posted January 14, 2008 OK, I have done everything that you all suggested and she still will not start. I guess its time to bite the bullet and get it to a dealer! I am still at a loss, however just two more questions for you: Firstly after checking and changing the woodruff key all looked fine. Still not starting so again checked the spark, looked strong but as I said before jumping around a bit. I left the ignition on and turned the flywheel with a spanner to see if I could get it to spark on TDS, nothing happened? But it does spark on the starter motor? Also there does seem to be a lot of fuel coming from the plug hole when it is removed and at one point combusted from the spark plug on the outside of the barrel!! Shame it wouldn’t do that inside the barrel!! Checked for continuity all looked OK. I would appreciate more ideas if you have any, if not thank you for your time so far. Best Regards Richard Link to comment Share on other sites More sharing options...
yoda Posted January 14, 2008 Share Posted January 14, 2008 OK, I have done everything that you all suggested and she still will not start. I guess its time to bite the bullet and get it to a dealer! I am still at a loss, however just two more questions for you: Firstly after checking and changing the woodruff key all looked fine. Still not starting so again checked the spark, looked strong but as I said before jumping around a bit. I left the ignition on and turned the flywheel with a spanner to see if I could get it to spark on TDS, nothing happened? But it does spark on the starter motor? Also there does seem to be a lot of fuel coming from the plug hole when it is removed and at one point combusted from the spark plug on the outside of the barrel!! Shame it wouldn’t do that inside the barrel!! Checked for continuity all looked OK. I would appreciate more ideas if you have any, if not thank you for your time so far. Best Regards It should spark before top dead centre. Check and see if there is continuety between the outside (ground) of the spark plug when fitted and the engine. The needle shoud be hard over otherwise that might be the problem. Also check the engine to the battery neg side and again it should be hard over. No resistance between any of them. Link to comment Share on other sites More sharing options...
f1springy Posted January 15, 2008 Author Share Posted January 15, 2008 Hi Yoda, OK I will test this tonight. Someone else said that it may be flooding due to a broken reed valve? What do you think of that idea? Thanks Rick Link to comment Share on other sites More sharing options...
fosdyke Posted January 17, 2008 Share Posted January 17, 2008 Hi Really sounds like a timing issue if the petrol is igniting with the plug out resting on the head. As to the broken reed valve - its possible - if you turn it over normally then take out the plug is it very wet? A very wet plug could indicate a broken valve. Let us know how it goes. Link to comment Share on other sites More sharing options...
f1springy Posted January 19, 2008 Author Share Posted January 19, 2008 She runs!!!! Went out this morning cleaned all the earths and connections I could find. Checked the reed valve. Re-Checked the carb. Still nothing! And this is the strange part, for some reason had a closer look at the starter motor! Don’t know why just clutching at straws I guess all looked OK but took it off and cleaned it up even though it was turning over the engine OK, or so I thought! With it off I thought what the heck try and bump it. It started after just a few feet! (Yes I had tried to bump it when it first stopped running to no avail) Don’t know why this should stop the engine from starting but what the heck, she runs! So I will be purchasing a new or second hand starter. I would really like to take this opportunity to thank all that have offered up suggestions to my problem. It’s a great site with loads of top guys on here. Thanks again fellers. Take Care Rich Link to comment Share on other sites More sharing options...
Moderator drewpy Posted January 20, 2008 Moderator Share Posted January 20, 2008 just a note on woodrough keys, they are only there as a guide and don't stop the magneto from turning, this is done by the taper on the crank and why you have a puller to separate the parts. Link to comment Share on other sites More sharing options...
fosdyke Posted January 21, 2008 Share Posted January 21, 2008 Agreed Drewpy - but have had a couple of instances where when the woodruff key 'went' the magneto 'slipped' and put the timing out - it is one of the first things I check on a stroker if I can't get the b****r to start and I know I have gas/compression/spark. Link to comment Share on other sites More sharing options...
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