I appreciate any input on where to go from here as this is a frustrating problem. Motor has been running fantastic. I left some accessories on and my battery was dead. I was about to go to the lake so I grabbed an older battery that had been working and was charged. When I touched off the starter the Tach went crazy the starter only whined. I am thinking that the battery is a internall short or something so I changed to another battery. The boat started but then died quickly after one backfire and now won't start. I have even compression 125 on all cylinders I checked with a spark tester all cylinders at 7/16" and I had spark. However still will not start. Where do I go from here? I am thinking switch boxes but not sure...Thanks for any help offered.

Opti what do you think? Thanks in advance

If the battery is bad but the engine cranks it will not effect the ignition system because it is a ADI ignition the voltage supplied to switchboxes is generated by the flywheel and the stator you say the starter whines is it spinning the flywheel if not check the bendix it could be stuck and not engaging the teeth. If engine will spin over and you have fire the only other thing it could be is the enrichment system not working properly and not dumping fuel behind bottom two carbs. Let me know....OPTI

Opti...that is interesting...the flywheel is definately spinning. One thing is that I have this boat running on double oil. It is 50 to 1 in the tank and oil injection hooked up. I was planning on doing this briefly as I had just swapped out powerheads. The powerhead I swapped and am using now is a used powerhead so no break-in was needed I was just being cautious unil I was sure the oil injection was reliable. you think this could have something to do with it?

Thanks again

I wouldn't think double oil would cause this pull the front cover off and spray carb cleaner in thoats of carbs while someone cranks the engine if it starts up then there is a problem with the enrichment valve not functioning properly I know everybody say not to use carb cleaner but I've been using it for 20 someodd years as a diagnosic tool not going to hurt it now if you set thare and spray whole can in carbs yea then you might wash the cylinders but quick burst is not let me know....OPTI

OPTI,
I sprayed carb cleaner and the engine fired. I checked the enrichment valve and it is getting 12 volts to the yellow and black wire. I pulled the bottom gas line on the valve and pushed in on ignition ----no gas...I was thinking bad enrichment valve like you said....but I pulled the top gas line to the valve and pushed in ignition...the valve is not getting gas. I have some kind of fuel restriction...I am thinking maybe fuel filter...it got dark on me so I will have to check tomorrow. You think I am on the right track? Thanks again!

Scanos....Your problem is the needle on the top carb is stuck closed that is were the enrichment valve gets the fuel from top carb. Get the needle unstuck and you will be ok Has this engine sat for any period of time say 2 or 3 month if so I would suggest going through the carbs.....OPTI

Thanks OPTI!! Last question.... is there a way to unstick the needle without tearing into the carbs? OPTI you are very much appreciated...I hope you can open your own shop like you want. I would drive from Nocona to Fort Worth anyday of the week for you to work on my boat! Thanks again

Dave

Scanos....The best way is to pull the fuel line off going to that carb and spray carb cleaner into the elbow then if you have access a air compressor apply a short burst of air into the elbow that should pop the needle loose from the seat....OPTI