Pontoon Boat & Deck Boat Forum

Can bad fuel cause a drop in WOT RPM and still let the engine seem to run good otherwise? I got some fuel at the Marina last weekend and just after I did, I heard the dockmaster tell someone that his low level switch had tripped and he was out of fuel. When I took the boat out for the day, it seemed to run great but my WOT RPM had dropped 700 rpm. I had blamed it on a newly rebuilt prop but yesterday I borrowed a prop to check that out and still got the 700 RPM drop. I would think if I got bad fuel it would affect performance across the board but it idles and runs great other than the top end drop.

Is your boat in the water all the time, on a lift or trailered?

Bryden24shp wrote:Is your boat in the water all the time, on a lift or trailered?

it's on a lift

Contaminated fuel can clog the fuel filter, the motor runs good til it tries suck up fuel faster than it burns it. It will often run at full rpm until you put it in gear and the fuel consumption goes up. If it has one the first thing to do is change the fuel filter.

illinoid wrote:Contaminated fuel can clog the fuel filter, the motor runs good til it tries suck up fuel faster than it burns it. It will often run at full rpm until you put it in gear and the fuel consumption goes up. If it has one the first thing to do is change the fuel filter.

I'd think this would be the first thing to check as it sounds like that's your problem.

Just my opinion.

I know I suggested this in a previous thread of yours, only because I had a similar thing happen to me a couple years ago. I got a previous boat out of storage and first time out I had plugged 2 of the 3 fuel filters on my Yamaha F115. I replaced all 3 filters and the boat ran perfect again. Now I run a large inline spin-on Fuel/water filter separator and have had no issues with either boat. There is a good chance you sucked up a bunch of crap off the bottom of that marinas tank on your last fill up...

rdeterman wrote:I know I suggested this in a previous thread of yours, only because I had a similar thing happen to me a couple years ago. I got a previous boat out of storage and first time out I had plugged 2 of the 3 fuel filters on my Yamaha F115. I replaced all 3 filters and the boat ran perfect again. Now I run a large inline spin-on Fuel/water filter separator and have had no issues with either boat. There is a good chance you sucked up a bunch of crap off the bottom of that marinas tank on your last fill up...

I picked up one this last weekend as well as new fuel filters and installed them but haven't had a chance to try it out. I had put one on my previous boat per your suggestion but hadn't had time to do so on this one.
Thanks again for the suggestion

wijames wrote:

rdeterman wrote:I know I suggested this in a previous thread of yours, only because I had a similar thing happen to me a couple years ago. I got a previous boat out of storage and first time out I had plugged 2 of the 3 fuel filters on my Yamaha F115. I replaced all 3 filters and the boat ran perfect again. Now I run a large inline spin-on Fuel/water filter separator and have had no issues with either boat. There is a good chance you sucked up a bunch of crap off the bottom of that marinas tank on your last fill up...

I picked up one this last weekend as well as new fuel filters and installed them but haven't had a chance to try it out. I had put one on my previous boat per your suggestion but hadn't had time to do so on this one.
Thanks again for the suggestion

Sure, no problem. Hope it fixes your issues!