Atrus
Jedi Warrior
Offline
Hey All,
I have a '68 Sprite 1275cc. I've been battling trying to get the timing/carbs set right (I'm 25 and grew up in the age of fuel injection /ubbthreads/images/graemlins/wink.gif )
Anyway, I made sure #1 was a TDC, and looked at the timing mark on the crank pulley - it was in the right position relative to the timing guide. I started the car up, got it to 10* BTDC...car actually seems to be idling smoothly, considering that I know the carbs are still way out of whack (had to be as I had the timing really off before). The issue I have now is the car seems to be backfiring through the carbs, spraying raw gas out the carbs. I would think the #1 culprit of this would be timing, which is why I made sure #1 was a t TDC and the mark was positioned corrrect, incase the engine was ever rebuilt and not aligned properly. When I severely retard the timing (about 40*), I get no backfire, this is where I had tuned it "by ear" prior to setting it with the gu today. Explains why it would never run correctly :O
One thought I do have is valve springs - do you think the springs could be weak, causing an intake valve to remain open? I don't know the milage or history of the car. When I got it, however, I do know that the carbs were shot (pistons seemed scored and warped on them) and off the car had sat for about 10 years. That indicates to me that a couple of valve springs were compressed for 10 years without moving.
Any advice/experience/tips would be appreciated. I have my registration coming hopefully this week so I can get this LBC on the road! I'm anxious!
I have a '68 Sprite 1275cc. I've been battling trying to get the timing/carbs set right (I'm 25 and grew up in the age of fuel injection /ubbthreads/images/graemlins/wink.gif )
Anyway, I made sure #1 was a TDC, and looked at the timing mark on the crank pulley - it was in the right position relative to the timing guide. I started the car up, got it to 10* BTDC...car actually seems to be idling smoothly, considering that I know the carbs are still way out of whack (had to be as I had the timing really off before). The issue I have now is the car seems to be backfiring through the carbs, spraying raw gas out the carbs. I would think the #1 culprit of this would be timing, which is why I made sure #1 was a t TDC and the mark was positioned corrrect, incase the engine was ever rebuilt and not aligned properly. When I severely retard the timing (about 40*), I get no backfire, this is where I had tuned it "by ear" prior to setting it with the gu today. Explains why it would never run correctly :O
One thought I do have is valve springs - do you think the springs could be weak, causing an intake valve to remain open? I don't know the milage or history of the car. When I got it, however, I do know that the carbs were shot (pistons seemed scored and warped on them) and off the car had sat for about 10 years. That indicates to me that a couple of valve springs were compressed for 10 years without moving.
Any advice/experience/tips would be appreciated. I have my registration coming hopefully this week so I can get this LBC on the road! I'm anxious!