My 1974 25hp. Evinrude backfires when I try to start it. When I do get it started it backfires and stalls out. I put new plugs in it and played around with the idle mixture but couldn't fix the problem. Does anyone have a idea what could be wrong?
When you say it backfires, does it blow out through the exhaust with a loud bang, or is it a more subdued blow through the carburator? Do I read you correctly that it will run just a bit and then backfire?
The motor backfires out the exhoust with a loud bang. The plug wire are in the correct place. When I start the motor it runs rough,backfires, and stalls out. Then when I try to start it again it will back fire when I pull the rope.
If you are certain that the flywheel key hasn't sheared, another thing to check is the armature plate. Is it (underneath the flywheel) turning smoothly as you turn the throttle?<br /><br />If the flywheel has not been torqued precisely to specs, the flywheel key will shear.<br /><br />Points set to 0.020? <br />EDIT: There shouldn't be any points. CDI ignition in '74 right?
Most times it will still be tight, just in the wrong spot. Its actually a taperd interference fit and the key only locates the flywheel. <br /><br />It may still be OK, but lets make sure.
I pulled the flywheel off, the key is in good shape. It does have points I checked the gap and that was good as well. So does anyone know what the next thing to check would be?<br /><br /> Also does anyone know what the torque specks are on the flywheel nut?
OK, the key is not sheared so we know the flywheel is in the right place. Good.<br /><br />Since the motor hasnt run in a couple of years, lets clean the carb and install a new OE kit. This needs to be done regardless.<br /><br />While we're on the subject of not running, we are assuming from your posts that you bought the motor and then tried to get it to run. Basically, you have never seen the motor run correctly, right?
I bought a 14' boat & trailer for $350. and the guy threw in the motor with the deal. The only time I've seen it run is when I had it running. It does fire off almost every time on the first pull, it just studders, backfires and dies.
Well, I rebuilt and cleaned the carb. The problem is still there. I got everything put back together pulled the rope about 5 times, it started, ran good for about a minnute, than the idle droped down, backfired and died. I just can't figure it out.
