1998 Yamaha 250 2 stroke hot start problem

Joined
Jul 5, 2007
Messages
6
Today, my yamaha 250 refused to start and run after lunch. I had hauled a boat load (eight of us) about 6 or 8 miles. The trip over went well, on plane, moderate speeds, and ran slowly last 1/4 mile or so at idle speed to the restaurant. Shut it off, went to lunch. When I returned, hit the key and it immediately fired off, but rpms dropped to 4.....3......2 then stopped. Attempts to restart got an immediate but brief fire, but no rpm and no ability to rev it up, before it would die. Successive attempts to start it got the same.

This is not a common problem, but it did happen once before, about a year ago. Ironically, it was the same story, boat load to the same restaurant.

Seemed like it was starving for fuel, so I started fumbling (a year ago) while at the dock. I removed the engine cover, decided to unscrew the filter bowl like thing and check for crud. Found no crud, so I put the bowl back on and just for kicks tried to start it. Fired right up and we all went home. I looked like a whiz!

Today, I did the very same thing and it immediately fired right up and ran fine all the way home.

Keep in mind I have used the boat on similar missions countless times in between with no such issues. I doubt that it is the restaurant.

What is going on? Any help will be appreciated.

Dave
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: 1998 Yamaha 250 2 stroke hot start problem

What is the model #?
Is it fuel injected?

Did you try pumping the primer bulb before pulling the filter or after?
 

Bamaman1

Lieutenant Commander
Joined
May 15, 2011
Messages
1,895
Re: 1998 Yamaha 250 2 stroke hot start problem

Modern 90/10 gasoline is quick to deteriorate. The alcohol breakdown produce acids which affect rubber parts in the fuel system, including some old style fuel lines. I take it your boat has a carb.

Bad gas breaking down often causes sticky needle valves in the fuel bowl--and cause the inevitable drip, drip, drip and engine flooding. My suggestion is to pull the engine cover and pull the flame arrestor covering the carbs. Get your engine fully warmed up, and cut off the ignition. Look down the carb throats to look for any drip, drip, drip.

Any marine 2 stroke engine with a carb periodically needs the carbs. removed and cleaned. It's probably a 1 1/2 hr. job, and no carb kit is required most times.

My Yamaha 2 stroke starts with a touch of the starter when the carbs are clean.
 
Joined
Jul 5, 2007
Messages
6
Re: 1998 Yamaha 250 2 stroke hot start problem

It is a fuel injected motor.

The model number is: L250TXRW

There is no enthanol in the tank. It has burned some enthanol from time to time, but none lately.

Thanks for your interest....let me know if you have additional suggestions or ideas.

Dave
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: 1998 Yamaha 250 2 stroke hot start problem

How did you end up with a counter rotation motor on that thing?

You never said if you have a primer bulb and if you used it when it did not start or if you used it after opening the filter on motor.

Need to figure out if it is fuel or spark related
 
Joined
Jul 5, 2007
Messages
6
Re: 1998 Yamaha 250 2 stroke hot start problem

I don't think it is a counter rotation motor.

I do have a primer bulb, but did not use it.

Sure sounds like a fuel problem to me. always fired right off with every try, just would not keep running nor rev up. Like only a trace of fuel was available each time I hit the starter.

Dave
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: 1998 Yamaha 250 2 stroke hot start problem

Pretty sure that is what the L stands for. http://www.yamaha-motor.com/outboard/07_curr_models_web.pdf

Maybe the thing is having a fuel supply problem,
I would think pumping primer would force fuel back into the system for start up. Something to try next time.
or you can try to check fuel pressures when it happens.
I kind of doubt you will have the necessary equipment with you when it happens though
 
Joined
Jul 5, 2007
Messages
6
Re: 1998 Yamaha 250 2 stroke hot start problem

Thanks, I'll try the bulb next time for sure.

I understand the logic of the "L" but it is running a standard prop and does quite well, so that is why I doubt it is a counter rotating set up. It was one of a pair, so it is possible. Maybe just the lower unit was changed. not sure.

Dave
 
Top