View Full Version : L18 Running Rich

07-04-2010, 09:09 AM
I have a 07 maristar 245 with 80 hours on a L18. When it starts, a lot black smoke comes from exhaust. It seems to run rich at all time but more rich during start up. It doesn't matter if its hot or cold. I had a mastercraft dealer check it and I was told that the big blocks need more fuel during start and that its normal. Comp program has been checked for the update. I don't feel this is normal and would like to know if anybody with this motor has the same issue.


07-04-2010, 09:50 AM
I've seen the LY6's run rich, (pig rich if you listen to our techs) we've been trying to get Indmar to write a better calibration for it but apparently they are not interested in helping. It might be worth a call to Indmar, the more pressure they get the more likely they are to help out.

07-04-2010, 09:57 AM
I thought about calling Indmar. I think they are located near me. I live just out side of memphis. Will they provide support to the normal guy or do you need to be a dealer?

07-04-2010, 10:10 AM
Rich is better then lean when it comes to the longevity of a engine. I have a 454 in another boat. It has always been rich and tuned fat. I called my dealer on that boat and questioned him about how rich it was. His reply was I can lean it out but I will be replacing pistons if I am not careful. Racing cars as a kid we always said lean is mean but rich drives home. With my Harley's I have them tuned rich. They run cooler rich. May not be environmentally the best but I believe it keeps them out of my shop. Unless you are having problems like excessive carbon build up I would not lean out that engine. Just my opinion--your boat.