Box Stock

engine trouble

H

hwater85

New member
I'm running a 212 hemi with a bp2 cam, 26lb spring , .020 over billet rod ,stock appearing carb and open exhaust. started running this at the end of last year with the stock tank and no fuel pump. Engine runs great for 3-5 laps then starts to break up and sometimes died completely. So, went to the track yesterday with fuel tank in the floor and fuel pump on the top plate. I had the same problem, Engine only would run 3-5 lap strong. What have i done wrong?
 
Typically speaking, with the symptoms you described, it will most likely be one of two problems. First is, fuel tank not vented properly. After just a few laps, a vacuum is pulled on the fuel system and it cant get enough fuel because of it. But you said you changed the fuel tank/system? If that's true it will be the second issue. Coil is bad. Very common on these Chinese engines. With heat, they "break down" and wont fire properly. I would change the coil and see if that fixes it. If you have an aftermarket flywheel like an ARC, and you set the gap too close, the superior magnet in the flywheel may cause premature coil failure. Set the gap to .050 or .060 with the new coil you put on IF you have an aftermarket billet flywheel. Good luck
 
If the problem only comes up once the engine is up to temp, 9 times out of 10 its a bad coil, especially if the problem is worse when you lift the throttle then get right back into it. Unlikely it's the float level in these carbs since it is not really adjustable like some are. Either you are leaning out too much as it gets up to temp, or coil is weak/bad
 
Thanks from the responses. I am running a ARC fly wheel. But I'm pretty sure I set it to there specs. But I will replace the coil and check for proper spacing. I pulled the plug at the track and it was nice and black so I think it's alittle rich if anything. I double checked the fuel tank cap. It was venting. The only thing I don't have is a crank case vent. Could that cause any problems
 
yeah, i have a billet high clearance valve cover that I'm using to pulse to fuel pump, so i have no vent or catch can. What is the best place to vent and what is the best place to pulse? thanks for the advice
 
Pulse from the intake if you can. Put a 1/4" pulse fitting in the top edge of the side cover and run that to a catch can. Make sure your catch can has a breather on it
 
You must log in or register to reply here.
Back
Top