C
Took for a rip today ran good for a few km then started to not run well. Backfires at idle
M7 backfire while idling wont idle
- Thread starter Catm7bigbore
- Start date
D
What's the temp there, could just be ice in the fuel otherwise sounds like either bad plug caps or a stator giving up. Also check for the infamous tail light wire short.
R
Look at all plug connections moisture may have gotten inside any of them and started to corrode!
C
Was like 9 degrees celsius and ill take a look at the plug connections. I have a bigbore in it with head word and im only running premium. Could it be major preignition?
J
What's the compression like? Did you detonate it?
C
Plugs look like one side leaned out and the rings on the lean side look bad 110 on the good side which is low and 90 on the bad side
J
Sounds to me like you detonated it. If you cause enough damage to the top of the piston, it essentially changes the port timing and it will backfire. 90 lbs is definitely too low. I hate to tell you this, but you probably need a new top end.
Also, if your rings are stuck or damaged, the blow-by can be extreme enough to cause the same symptoms.
Better pull the head and see what you find. It should be evident.
Let us know what you find.
Also, if your rings are stuck or damaged, the blow-by can be extreme enough to cause the same symptoms.
Better pull the head and see what you find. It should be evident.
Let us know what you find.
J
What's the update? Did you find anything?
C
I pulled the engine more damage than i though. Dontated on one side bad and broke a skirt off. Had to get the case welded and do a pisons and rings. Running 1 gal c14 race gas and a third of a quArt of oil per tank just on the safe side
C
Also iat idle if i set the idle mixture so it will run it says its too lean but if i set it at a 15:1 ratio at idle it will die? Any awnswers
J
Set the idle mixture so it does just that. Idles without loading up the engine and dying. As lean as you can while keeping the idle at 1000-1500
C
Okay thanks for your helpAk
