Yamaha 4.3L Fuel issues/

[ShaunTacOps]

Hey Guys,

I'm a new boat owner and new to the marine world..... I got a hand me down 93 Chapparal with a I/O 4.3L yamaha motor and outdrive. The boat sat for a little over 2 years before it was given to me. The motor is strong had compression check and everything done had it serviced and inspected at a local marina. After and extensive floor and stringer repair I put the boat out on the water today for the first time. I stopped by the gas station and put a 1/2 tank ethanol free in the boat and hit the boat ramp. Got the boat out on the water and it ran awesome for the 1st hour+...... Then because the gas gauge isn't working real well.... I stopped at a marina and filled up with more ethanol free. About 20 minutes later the motor started running ruff. RPMs jumping up and down boat losing power and sometimes stall out. Would start it back up and it would run fine for 2 to 5 minutes then do it again, or sometimes continue to do it for like 5 minutes at a time. But just sitting on the water the motor would run up in neutral just fine with no sputtering or anything. I'd run the RPMs up to like 2500/3000 for a minute or 2 and nothing....

What do you think the problem could be.... I tried to speak with the marina guy who worked on the motor to see if he changed out the water separator but he was too busy to take my call.

I'd appreciate any input.....

 

[Bondo]

I tried to speak with the marina guy who worked on the motor to see if he changed out the water separator but he was too busy to take my call.

Ayuh,.... Welcome Aboard,..... So change it again, 'n inspect the contents of the take-off filter for water, 'n crud,.....

It might take 1/2 dozen changes to get rid of crap from the tank,.....

 

[ShaunTacOps]

So worked problem out on my own. Siphoned out the entire tank, cleaned all the old fuel crud and water out the bottom, swapped out separator, and replaced filter. New ethanol free fuel, a can of sea foam and it ran like a scalded dawg!

Turned out that the marina guy I took the boat to hadn't changed the separator or the fuel filter. When I dropped it off I asked him to swap out and service all of the things he thought would need attention on a boat that sat for 2-3 years..... So one would have assumed that those would be some of the things addressed... But It's done....