Yamaha dt3 breaking up with throttle. Please help!
I have checked my points gap and it is right at .014" and I'm pretty sure I got the opening right. I can't figure out a method with my volt meter to check when they open, but I used deets home made tool method to verify .126" before tdc. I eye balled the opening and I feel it is close, close enough to run for sure.
I did rebuild the carb but made sure everything was clean and used new gaskets and a new main jet o ring. I've had something similar happen on my at2 and the o ring was the bad guy.
I'm trying to get this thing going so I can break in the new rings and bore and ride and enjoy it!
Edit- A lot of problems start with the carb a good cleaning as you have done. Sounds rich but after a cleaning on the old car carbs, then working on the points as you did, and perhaps a look at the condenser or bad coil. A good tune up always entails replacement of the spark plug. Might be a bad insulator there or fouled.
Member Hammer has a method of putting an AM radio tuned to static near the magneto and listening for a "pop" when the points open.
Then after timing is set, you measure the max gap and if it doesn't fall within the specified range then you probably need to replace the points...
Or in a pinch, you can gap the points and the timing is usually close... I would gap at 0.012" to start.
In my experience, "looking" to see when the points open usually ends up with advanced timing... I'd try closing the points up a little
I already pulled the air filter and it is doing the same thing. I don't think my exhaust is plugged. I tried setting the timing to a little retardation and it still happens.
I don't think anything is going on with the carb but I'm fixing to tear into it and see if I can find anything. I cleaned it pretty good. (Ultrasonic)
I'm just at a loss here.... trying not to get frustrated. I just have so much time and money tied up in this bike and I just want to ride it.
I will see if I can make a video of what is happening .
RT325 wrote: Not sure what to think sorry. Sounds quite healthy at idle but not enough to hear higher up to say if too rich on the needle [which it sort of sounds like] or if it's heading into an electrical misfire. Idealy just hold it on full song & see if it clears or gets worse--worse as in drowning from the little Oring not sealing. If 'that' & you feel the Oring is good then 'is' the thick washer missing from where the Oring fitting screws into the needle jet. If so--then the Oring won't go far enough into the lead into the hole to fully seal. That's a wild guess because i can't judge what's happening with a short one or two revs on the first video. Thanks heaps for the vid as know it's not easy to do [not for me anyway lol] Longer vid & on the road under full power or stationary & see if it clears. Think about that Washer. No6.
Yea the driving video was something I wanted to get but isn't happening with out me rigging up a mount.
I put a brand new oring in place and yes the thick washer is there, I just pulled it apart today.
One thing I will say is there is a slight scale looking substance that is in the whole where the o ring goes into. I tried like hell to clean it up during the carb rebuild but didn't make any headway. I still don't think it is that though because I took my filter out and it didn't improve at all.