Kevin 007 Posted August 9, 2010 Share Posted August 9, 2010 -I recently acquired a 74 dt360 that had no spark. Was running well till it just died and wouldn't start. Found a used CDI for it and it then had spark. I pulled the flywheel and cleaned everything up under there and then had a better spark. Cleaned up the mess of a wiring harness, made sure the cdi was grounded well and taped everything up to look pretty. -Ran a bunch of compression tests which showed between 115psi-125psi. Usually around 119-120psi. -Carb is clean and float valve seating well, airbox open. -Cant see any gaps between the reeds and the cage, got a new cage and reeds on the way however. -Using new spark plugs, I get the best spark with a NGK B8ES. At this time it was trying to start, it would sputter for a split second then die, and I would be getting some smoke out the exhaust. but after so many tries, the plug kept coming out wet. So I figured the crankcase was flooded so I pulled the exhaust and drained a few ounces of fuel out of it and flipped the bike over allowing the fuel to drain out the plug hole. Now the plug is staying dry, but it doesn't try to start anymore!!! Ive tried a little fuel down the plug hole and in the carb....to no avail, not even any smoke. same goes with starting fluid. I still have compression and still a spark. Ive tried push starting it down a hill...to no avail also. sounds exactly how it should if I had the key off and there is no spark. but when I pull the plug to check; there is a spark. So im stumped!!! Things I found strange: -only get a spark with the battery (new and fully charged) out. No spark with battery connected -Only have a spark with the signal switch in the center or RH signal position. No spark in the LH signal position. -I rigged up an AC Delco coil on it to see if that made a difference, but it didn't. The spark looked identical How would I go about checking the timing on these things?? I dont think its been messed with in the past as its a low mileage machine that hasn't been rebuilt and never abused. The pick up coil is currently positioned in the 11:50 position, just to the left of 12:00 clock. From what I can see of the piston and cylinder through the intake and exhaust ports, the piston has very little blowby and is nice and smooth on top and has no more than the usual play in the cylinder. Cylinder has almost no ridge up top and the rings are free, not stuck. Can anybody help me???? Im new to Yamaha's Link to comment Share on other sites More sharing options...
Tommy10bikes Posted September 30, 2010 Share Posted September 30, 2010 I also have a DT360 but it does runn and run well, sound as if its the generator coil that broken down, especally if it only sparks on a charged battery, plugs can break down even new if they have been in and used on a bike that miss fires. Is there any oil residue around the back of the stator plate, regards the timing im sure this is preset and cant be changed. Cheers Tommy10bikes TTB for short Link to comment Share on other sites More sharing options...
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