'08 90 2 stroke stalling.

[tddfrt1969]

Hi guys. Boat has been laid up about a year, and was running fine the last time it was ran. Went to crank it with the ear muffs and it would run fine in high idle, but sputter and die when i drop it to idle. Stabil was in tank, and I'm hoping it is only a stuck float or something wiith the carb. Do you think running some seafoam in the gas and running it at the high idle could help if it was just some varnish or something sticking? Not very mechanical, but the engine only has about 30 hours on it, so I don't think its major. Thanks for your help.

tddfrt.

[99yam40]

I would drain the tank and start with some fresh fuel. Year old fuel has a hard time even with additives.
If you did not drain the fuel bowls and lines before setting up for a year you will probably need to clean them also.
Running to try to get it to clear up could lead to major problems if it is running lean fuel/air ratio on one or more cylinders

[tddfrt1969]

How do you drain a built in tank? Do you have to pump it or is there an easier way?

[throrope]

tddfrt1969

Sounds to me like the pilot jets in the carbs got crapped up.

Before emptying the tank, I'd get a one gallon gas can with fresh premium, put the fuel line directly into the can and run it to see if it makes a difference.

Our boat sat for god knows before we bought it and the gas was so poor it stank. Since these two strokes run less than 6:1 compression, we ran it out without difficulty.

Incidentally, our carbs were clogged and miss assembled which made ours run like crap until I bought the factory manual and endured a learning curve.

Good luck and keep us posted.

[99yam40]

You really do not want to pop a piston if things are plugged up , so clean everything up.
Pump or suck it out anyway you can, there are no drain plugs on inboard tanks by design so they can not leak fuel into the bottom of the boat and cause a fire or explosion. Take some out and look and smell it to see what shape it is in, but I would get all out and start fresh

[rodbolt17]

DO NOT attempt to run it until the carbs and fuel lines and fuel pump have been cleaned properly and the dead fuel in your tank disposed of.
if it runs lean due to a clogged jet and you run it under load there is a very good chance your 30 hour engine will detonate a piston.
happens,a lot.
its not a matter of compression ratio, its a matter of air to fuel ratio.
the difference between welding with oxygen acetylyne and cutting with it is a matter of air to fuel ratio.
leaner it gets the hotter it burns.
and it can and will get hot enough to actually start melting the piston crown at the edges, typically the ex side first and then the piston scuffs and trys to stick to the cyl bore and bad things hapen and techs like me buy new cars on your dime.

[throrope]

I defer to rodbolt17. If he sounds the alarm, take heed, for all who do not will surely regret.

[tddfrt1969]

Is this something a novice with a seloc manual can do, or would it be better to leave for a professional? Thanks again guys.

[99yam40]

Not hard to do, but I have no idea how well you will do if not very mechanical.
read the manual and search the forums and then decide if you want to take it on yourself.

Here is one just down the page from yours called carburetor cleaning methods that has some info from Rodbolt

[throrope]

Is this something a novice with a seloc manual can do, or would it be better to leave for a professional? Thanks again guys.

Not difficult, just take your time, make room to lay out parts, a pan or tray helps and don't force anything. I have the factory manual ordered from Yamaha's website and wouldn't use anything else.

[tddfrt1969]

Pulled and cleaned carbs and she started and idled like a champ. Good bit of varnish in the bowls. Lifted float and sprayed, pulled jets and sprayed. Put a can of seafoam in fresh gas and took her out. No problems at all. Thanks for everyones input.