Recently aquired a 1978 DT 125e. It has been sitting for at least 20 years. So I knew it was going to take some doing to get it on the road again.
Here is a list of the things that I have replaced:
1. Battery
2. Air filter
3. Coil
4. Points (I didnt replace the condenser because in my experience they usually dont go bad, plus it was hard wired in an looked to be a PITA)
5. Fuel and Oil lines
6. Removed the carburetor and rebuilt it leaving the float set at were it was when I removed it.
I checked:
1. cleaned the gas tank and the fuel switch, including the strainers. (it drains fuel at about a half gallon/min now)
2. had to free up the stuck clutch disks.
3. reprimed the oil pump and resealed the clutch cover. (I started it with premix fuel just to be safe.)
4. has good hot spark.
Kicked it over and.....Horray! It seemed to run great. So I thought...
It ran just fine for about 5 minutes and then it was just like someone reached up and turned the key off.
I did some more adjusting on the carb and kicked it over after working on it for about 10 minutes.
It fired right up just fine, returned to idle. A slight crack of the throttle and it winds up great. So I decide to take it around the block for a quick spin. Get half way around and it dies again...no stuttering, no amount of twisting on the throttle or messing with the choke will keep it running. Again, it was just like you reached up and turned the key off. I kicked and kicked on it to restart it to no avail. I checked the spark right after it died and it had great spark. Reinstalled the spark plug and kicked it and kicked it and kicked it. No startey. Must be a fuel problem right!? Wrong. Removed the carb again. Everything was in order and functioning as it should. Reinstalled carb, kicked it over. It runs. like it always did; great. It runs great for about 5 minutes then it dies again. No restart until it sits for about 5-10 minutes and then it runs just fine....for five minutes. You get the picture. What am i missing? Thanks for reading and any help would be much appreciated!