Hell on Wheels
Member
- Local time
- 8:38 PM
- Joined
- Sep 26, 2018
- Messages
- 152
I'm running a DIO reed kit with a Runtong 16mm carb (dellorto SHA knockoff). Stock muffler chopped off at the weld. Moderately windowed piston and light exhaust port raising (2-3mm). Timing advanced half of keyway (approx 20 degrees)
Runs rich but leans out as time goes by. Confuses me like crazy. I ran a 77 jet and its (expectedly) rich. I went down to 67 ish (soldered 70 micro drilled out) and it 4 strokes sometimes. It then leans out and it 4 strokes less then eventually the engine loses power and dies.
Give it a minute with it off and all my power is back.
I noticed signs of detonation on the spark plug but the plug is ashy brown. No blistering. The piston is the same color brown and no signs of detonation (pitting, melting) on it.
I personally think the spark plug ground electrode is getting so hot it's causing preignition. I'll try retarding timing back closer to stock. But anyone else have any idea what it could be??
Runs rich but leans out as time goes by. Confuses me like crazy. I ran a 77 jet and its (expectedly) rich. I went down to 67 ish (soldered 70 micro drilled out) and it 4 strokes sometimes. It then leans out and it 4 strokes less then eventually the engine loses power and dies.
Give it a minute with it off and all my power is back.
I noticed signs of detonation on the spark plug but the plug is ashy brown. No blistering. The piston is the same color brown and no signs of detonation (pitting, melting) on it.
I personally think the spark plug ground electrode is getting so hot it's causing preignition. I'll try retarding timing back closer to stock. But anyone else have any idea what it could be??