So I bought this boat that had been sitting up 10 years. Has dual tanks. The left works fine. But when I switch to the right it coughs and dies. Do you think its water in the tank? Or something clogged up? If its water do I just drain it and fill it up? What do you do with 10 gallons of bad gas?

How old is that gas? First of all, I would replace all fuel lines, filters, buy ya a fuel/water separator if it doesn't have one or replace the filter. In short...clean the whole fuel system.

I'm amazed anyone would actually try to use the 10 year old contents of a fuel tank. Based on what you've done so far, my best suggestion is take the boat to a reputable marine dealer and tell them the boat has been sitting 10 years. I would never have run on the other tank either. It could still be trouble if you pick up something in the tank you don't want to go toward the engine.

Can you say contaminated carbs/injectors?

Team Reelin in the Blues has a YouTube video series for motors that have sat that long. Rule #1, don't start the engine.

take the fuel line off the engine, keep the bulb hooked up.
get 3' or so of auto fuel line and hook to bulb output, put in jug and sqeeze bulb a few times to start siphon.
drain both tanks, put 5 gals in ea. with 2 cans of seafoam in ea. and put on muffs. run it in the grass (you will stain concrete bad doing this) on idle till to temp then barely raise rpm to like 1,500 or so for a second or 2. do this for about 15 mins. after it hits temp then shut down overnight.

next day, go run the peedoodle out of it on a lake (have extra gas in a jug along, just in case) till almost empty on both tanks.

on way home fill both tanks with at least 2 cans ea. of seafoam.


change plugs and you should be good to go.


you probably have a lot of varnish in the fuel system and this should clean it out.

new plugs, 6 cans seafoam, one weekend and you should be good as it will get. still have problems then a mech is next.

First thing I would do before running it is to make sure all the fuel lines are rated for ethanol. Next I would add a separate fuel filter between the tanks and the engine.

Just drain out the tanks, put on a good fuel filter and fill with fresh gas. Why does everyone makes things so darn complicated?

Just drain out the tanks, put on a good fuel filter and fill with fresh gas. Why does everyone makes things so darn complicated?

The reason I think it's complicated is that varnish in the fuel system will RUIN an internal combustion engine if said engine is force fed the varnish.