Logo
FULL SITE MENU

260 alpha no power under load

H

hgm

New member
"I have a 86 260 with Thunderb

"I have a 86 260 with Thunderbolt ignition. After the engine was warm I started to get a back fire at WOT above 4000 rpm. Partial throttle would run fine till about 3500. I parked the boat for a couple hours and had trouble restarting but it finally started. After it started I switched fuel filters. Boat ran fine for a little while than started to break up and back fire again. The back firing got down to about 3500. When I got back to the dock it wouldn't restart. The next day it started right up. I replaced the ignition sensor, distributor cap and rotor. I started it and let run for a while at home before putting it in the water again. When I got to the water it was a little hard to star. Idling out of the marina every thing was fine and when I applied power the RPM came up to 4500 just fine. Boat did seem a little low on speed at wot. I cruised for about 1 mile at 3000 and then attempted to open it up again. The engine bogged very bad. The problem got worse, no power, could not even get on plane. I switched filters again no change, I open the valves to both filters no change. A couple of times as I was nursing it home it would seem to clear up for a minute and run fine but problem would come right back. Fuel- I am now running 15% ethanol. I starting using it at the end of last year. I filled the tank for the winter. Used about a half a tank of that the first time out and refilled before I want out today. Sorry for the long post but I wanted to try to cover everything. Thanks"
 
Im just guessing that it might

Im just guessing that it might be water in the fuel from the way you described the way it ran after you changed the fuel filters. Add som fuel conditioner that absorbes water (alcohol Based). That may help. Usually the warm and cold cycles that fuel tanks go thru create condensation which is why we have to top off whenever we can "afford it"... $$$Gas is so high!
 
That's what I am thinking.

That's what I am thinking. I have a 60 gallon tank that was full on the first run out. I topped it off before I took it out today and put in 28 gallons (the first run out was a long one) I just pulled one of the filters and put the fuel in a clear jar. I will see what it looks like in the morning.
 
"Water in the fuel sounds like

"Water in the fuel sounds likely to me, had the same problem earlier this year it would get on plane and die shortly after that. I put on a water sep filter with the drainable reservoir on the bottom and drian it every couple of trips out. no problems since!"
 
Update: I pulled one of my fil

Update: I pulled one of my filters last night and poured it into a glass jar to check for water. After 24 hours no water is showing in the bowl at all. I pulled the second filter tonight and will let the fuel sit overnight to check for water. While it was acting up the motor backfired a couple of time. Would water in the fuel cause a backfire?
 
Back
Top