Trialeovince

As it was found out, corrosion is not part of the problem and stator couldn't just "die" while the bike was sitting in garage. Same thinking goes for the CDI unit, it couldn't be "fried" as it wasn't getting any energy while bike was standing and it couldn't be corroded as it is sealed with epoxy. Somehow the two were ruled out. Wiring was checked so it was ruled out as well. One thing that wasn't touched since it was replaced with new part is pick-up coil. New pick-up coil is not available to buy separately, so a non-OEM part was used (different color code on wires). As it turned out it was not connected as it was supposed to be. Once the two wires were switched, spark appeared with the first kick. Seems like there is more than just coil in this "pulse generator." Problem solved - polarity of replaced pick-up coil was switched. Most of the time pick-up coil is used in combination with rotor that has some kind of bulge or tooth on it (signal rotor on the attached picture). But not on this bike. Flywhell/rotor actually has some kind of hole or channel recessed in it. Could this affect how pick-up coil works? Or is there some other explanation of the problem that was encountered here?

Expectations were the same, but this are actual values. Unfortunately I have no additional informations about CDI unit. This is the stator of 315R. Originally posted by "www.trialsbikebreakersuk.com"

Indeed it is bigger in diameter than suspected. I believe he got that reading on Scorpa (according to the profile info), so values might not be the same for Montesa. Nevertheless measurements were taken today with the same method as he mentioned (no peak voltage adapter, AC voltage range). - CDI connected: readings up to 24 VAC. - CDI disconnected: readings up to 15 VAC

No difference in peak output voltage of exiter coil between spark/no spark event spoted. Only thing noted was that spark appears when kickstarter is already returned to starting position and not while actual kick. As if spark came with a delay. Spark plug cap wire trimmed - no difference, no spark. Stator taken off the flywheel cover. Corrosion was present as predicted. Seat on flywheel cover, metallic part of the stator and bolts were cleaned using wire brush on rotary tool - no difference, no spark. Stator does not have a ground wire. Exciter coil (10,8-13,2 Ohm/25°C): actual value 12,6 Ohm/19°C Other coils: - primary ignition coil (0,45-0,55 Ohm): 0,6 Ohm - secondary ignition coil with plug cap (12,4-16,8 kOhm): 14,6 kOhm - secondary ignition coil without plug cap (8,6-10,6 kOhm): 9,7 kOhm - charging coil (0,64-0,79 Ohm): 0,8 Ohm - pulse generator (90-110 Ohm): 120 Ohm This thread is about one of two 315Rs that were known to be imported and sold new in our country. So chances to swap the CDI for a known good one are... lets say limited. This is why I would be very grateful if another user of 315 would take a measurement of exciter coil and pulse generator peak voltage. If those are somewhere near values I have measured then CDI is probably cause of the problem. But I would not like to buy a new CDI only to get to know that it is actually stator that is causing problem. And vice versa. Mentioned above - 19°C. Coils heated with fan producing heat of approximately 170°C. As coils were heated, resistance slowly increased from 12,6 Ohm to 14,2 Ohm. Then heating was stopped. Peak voltage adapter used to measure stated values was built according to this link, but using smaller capacitor (4,7uF). This is what has been done before. - stop button removed - no difference - rectifier unpluged - no difference - non of the wiring on coils is connected to ground - all wires connected to CDI unit checked for continuity - all OK - all joints cleaned with contact claner although none were visuably corroded Unfortunately I do not possess scope or function generator to replicate pulse. I am suspecting CDI from beginning, but as mentioned above - before I order new one I would like to know that voltage values from stator coils are OK for this particular model. Exactly my thoughts.

Will defenitly check. Here it is: Original post:: https://www.trialscentral.com/forums/topic/4980-cota-315r-help-needed/

Measured peak voltage raises until about 3rd or 4th kick and then stays around 20V. Voltage raising is presumably due to capacitor charging in peak voltage adapter. While taking measurements all loads were disconnected (in this case CDI). As mentioned everything was disconnected while taking measurements so I am unable to give you the answer at the moment, however I will try this out.

- charging coil (connected to voltage regulator) gives around 20V while kickstarting - exciter coil (connected to CDI) gives same 20V while kickstarting With peak-voltage adapter and multimeter, spark plug removed from engine while measuring Stator and pick-up coils are mounted on flywhell cover. If cover is removed, no electricity will be produced. As mentioned flywheel cover with mounted stator coils were removed from engine. But I did not separate stator from flywheel cover. Do you think stator is grounded via cover? Even when resistance readings are OK?

So here goes the story. Bike was lightly rinsed with water after riding (with garden hose - to remove chunkier pieces of mud) and later started so it dried out. Then It was stored for a year or so. When I attempted to start it there was no life in it - no spark. All coils were checked via resistance test and were OK (according to values in users manual) apart from pick-up coil which was bad (infinite resistance). Seems like some water came in stator department via hole for breather tube and damaged pick-up coil. But then again bike was never easy to start anyway.. New pick-up coil was fitted but the problem persists, only now it throws spark from time to time randomly. Sometimes strong, sometimes weak, most of the time none at all. If bike is left to stand for couple of minutes spark appears after 3rd or 4th kick. After that none, not until bike is left to stand a couple of minutes again. Then the process repeats: spark or two after 3rd kick and then none. What has been done so far: - all stator coils tested for resistance - OK - pick-up coil tested for resistance - OK - ignition coil tested for resistance - OK - spark plug lead (with and without cap) tested for resistance - OK - new spark plug (NGK BR6ES) fitted and adjusted according to users manual - both "grounds" cleaned and checked for continuity - OK - all cables/leads from stator dpt. to CDI unit checked for continuity - OK - all cables/leads from CDI unit to connectors checked for continuity - OK - "stop" button measured (OK), then disconnected just to be sure - voltage from voltage regulator around 12,4V while kickstarting Peak voltages were also measured (via peak-voltage adapter, all connectors disconnected while measuring): - pick-up coil gives from 8 to 13V while kickstarting - charging coil (usually connected to voltage regulator) gives around 20V while kickstarting - exciter coil (usually connected to CDI) gives same 20V while kickstarting Does anyone know if these peak voltages are OK (not specified in users manual)? Or if someone could measure them on working Cota 315R that would be great. If all this is normal, then only one thing remains - CDI unit. Any ideas how to test it? New one is hard to get and not at all cheap, so I would like to be sure it is bad before ordering one. If somone could check continuity between "ground" and green-white wire on CDI side (while disconnected from pick-up coil) I would also be gratefull. Mine reads "0" - it is shorted to ground. Any other ideas what to check?