t0m541 Posted April 19, 2014 Report Share Posted April 19, 2014 Hello folks. I recently purchased a '99 Techno and have been having issues. When I bought the bike it was bought as a non runner, not quite a basket case but certainly been well neglected, the previous owner had bought it in the same condition. When he bought it, it needed new rings, as that was the reason for it not running, which he had fitted, but then still couldn't get the bike to fire up. He was then told that the CDi and possibly the coil were goosed..and as he had already ploughed a good sum of cash into the top end rebuild he didn't want to go any further into finacial loss. So he asked me if I was interested in it as I already have other bikes and am a qualified mechanic, the price was right so I took it on. Since buying it I've stripped out the electrics which resembled a rats nest and rewired it, (thanks go out to Gary at Beta UK for a clear, (though Italian) wiring diagram). Now it has decent earths and everything is connected correctly. I've cleaned the carb through and set it up as detailed in the PDF on here, put a new fuel filter in and a tankful of fresh V-Power fuel with an 80:1 oil ratio. I have had the bike started and running, at one point for 15 minutes till I stopped it using the kill switch wires. However, since that time, though I've had the bike started, it never seems to want to run for more than a couple of minutes before dying then refusing to start at all. I have had the flywheel off and checked the timing which is central on the slots and I have a nice spark now that I've taken out the resistor plug cap that the previous owner fitted and got the correct plug (BP7ES) rather than the BPR7ES that was in. When I had the flywheel off I made the mistake of refitting it with copperslip on the stub and of course sheared the woodruff key, however, before it did the engine kicked and fired straight up with very little effort. I have fitted a new key and torqued the flywheel nut up using an impact wrench, (after cleaning the copperslip off). but the bike is really reluctant to start now, I've had it fired up a couple of times but it won't run cleanly and just dies out. It only seems to want to start with the throttle part to full open, won't even try to fire with choke on. I have been trying different plugs as I bought a set of 4 as it is wetting the plugs when not firing up and I still have a nice chunky spark. When I had the bike running for the 15 minutes I set the carb up and got a nice smooth tickover, which is making the non start issue a real puzzler. I'm tempted to pull the flywheel again and check that the woodruff key hasn't sheared again, but as the impact wrench I used is rated well over what the torque setting is and I used anti-vibration washer to make sure the nut doesn't rattle loose too, I'm pretty sure it's all intact still. So any ideas folks ?? all input and suggestions are welcome and gratefully recieved. I'm in no rush to ride the bike as it has other issues, (suspension bearings etc) to resolve before it gets used, but would like to have it at least reliably starting and running.. Quote Link to comment Share on other sites More sharing options...
t-shock 250 Posted April 19, 2014 Report Share Posted April 19, 2014 Failing stator, common fault on these engines, one of the symptoms is it will run until slightly warm, then quit. Quote Link to comment Share on other sites More sharing options...
nelly1 Posted April 19, 2014 Report Share Posted April 19, 2014 id say the same too Quote Link to comment Share on other sites More sharing options...
zerorev3rev4 Posted April 19, 2014 Report Share Posted April 19, 2014 use a strobe light to determine if its sparking on each kick or failing when t conks Quote Link to comment Share on other sites More sharing options...
t0m541 Posted April 19, 2014 Author Report Share Posted April 19, 2014 I've checked the flywheel/crankshaft alignment and it's still as it should be, so the keys intact. If the stator is failing then reading previous posts on these forums it would seem that Motoplat is the place to send it to get it tested and rewound if it needs it. I forgot to mention that I have de-coked the exhaust too.. One thing I have just noticed is water around one of the cylinder head bolt washers...I'm guessing that this might mean that the head gasket is leaking between the waterway and the bolt holes...maybe whoever did the cylinder head and rings didn't fit a new gasket or badly fitted it..looks like that's going to have to be stripped and replaced... Quote Link to comment Share on other sites More sharing options...
t0m541 Posted April 20, 2014 Author Report Share Posted April 20, 2014 Reading this thread .. http://www.trialscentral.com/forums/topic/22157-01-beta-rev3-250-electrical-problems/ I've checked the different coils and found that the resistance for the primary ignition coil on the stator is 200ohm and no earth leakage. I've also found that there is no connection between the stator and the engine casing, none of the wires in the multi plug have an earth.. I would have thought that the stator would have been earthed through its frame and that one of the wires...presumably the yellow earth wire for the lighting circuit or the brown for the ignition circuit would have rung through ... Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted April 21, 2014 Report Share Posted April 21, 2014 Quote "It only seems to want to start with the throttle part to full open, won't even try to fire with choke on. I have been trying different plugs as I bought a set of 4 as it is wetting the plugs when not firing up and I still have a nice chunky spark." Sounds to me like a carburetor problem. Float sticking? or Sunk? Was the tank clean inside before you added fuel? Quote Link to comment Share on other sites More sharing options...
t0m541 Posted April 21, 2014 Author Report Share Posted April 21, 2014 Quote "It only seems to want to start with the throttle part to full open, won't even try to fire with choke on. I have been trying different plugs as I bought a set of 4 as it is wetting the plugs when not firing up and I still have a nice chunky spark." Sounds to me like a carburetor problem. Float sticking? or Sunk? Was the tank clean inside before you added fuel? Yes clean tank clean fuel and new fuel filter, carb has been cleaned and blown through with and air-line and set up as set out in the mikuni sticky in this forum.. The spark went really poor yesterday and I've now managed to fry the CDI by experimenting with a battery off one of my road bikes trying to boost the output voltage to the coil... I'm consoling myself with the view that the CDI was shot in the first place.. Quote Link to comment Share on other sites More sharing options...
t0m541 Posted April 22, 2014 Author Report Share Posted April 22, 2014 I managed to purchase a known working stator and CDi yesterday, fitted the CDi first with my stator, didn't get much of an improved spark. So I then fitted the stator too...which really built a good spark...that was last night.. This morning sees torrential rain so I shoved the rear end of the bike out of the kitchen door... Gave it a solid kick and it fired up instantly and ran sweet... Last night I compared the stators side by side...my stator showed 199ohm on the primary ignition winding constantly, however the good stator showed that value only briefly before zeroing...so I'm guessing that the windings on the original stator are breaking down though not completely. I'll see about getting it tested at a rewinders and getting it repaired as a spare.. Quote Link to comment Share on other sites More sharing options...
t0m541 Posted April 28, 2014 Author Report Share Posted April 28, 2014 As an update to this thread, I have managed to have a ride about on the bike, which runs great, set the carb up so that it actually needs choke and a little bit of throttle now to start. So now the engine is sorted I have started on the play in the rear suspension, which is coming from the lower shock bearing. Of course now I have the linkage off and cleaned, I'm going to change all the bearings as a couple of them are certainly crunchy and notchy. I have managed to obtain 7 bearings from an online bearing supplier for £60 delivered, the most expensive one being the lower shock bearing as it's a rose joint bearing, which Beta wanted £40 + vat and delivery for.. Just need to obtain some new stainless bolts to replace the rusty versions that came out and rebuild the thing. Quote Link to comment Share on other sites More sharing options...
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