Yamaha O/B (?)

khoi30

Seaman Apprentice
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Nov 1, 2006
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40
After a day using my boat. I flush the engine out with fresh water. My question is do I unplug the gas line out.And let the engine run until it run out of gas and stop. Or can I just leave the gas line hook up to the engine. I used my boat about 2 times a month.
 

JB

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Re: Yamaha O/B (?)

What engine are you using, Khoi?
 

deejaycee_2000

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Re: Yamaha O/B (?)

Yes, I run all the fuel out of all my outboards, (although there's alot of opinions about this here) I find that it pro-longs the time for a carb rebuild .....
 

rodbolt

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Re: Yamaha O/B (?)

answer JB's question.
better yet post the model number and is it oil injected..
 

khoi30

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Nov 1, 2006
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Re: Yamaha O/B (?)

sorry its a Yamaha 1997 90h/p . Forgot the model # and its oil injection
 

JB

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Re: Yamaha O/B (?)

Don't do it, khoi. Two reasons:

1. The three carbs will run out of fuel at different times. Then one or two cylinders will be pulled through dry. Long term damage is probable.

2. When the fuel stops pumping the oil continues, loading the carb bowls with oil. The oil is too thick to flow through the jets alone and will eventually clog up the works.

The reason I asked about the model is that the practice is pretty low risk with a single carb, premix engine and leaves the carb bowl pretty much empty. That is why the practice began back in the old days when almost all outboards were single carb and used a very oil-rich premix.
 

JB

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Re: Yamaha O/B (?)

Don't do it, khoi. Two reasons:

1. The three carbs will run out of fuel at different times. Then one or two cylinders will be pulled through dry. Long term damage is probable.

2. When the fuel stops pumping the oil continues, loading the carb bowls with oil. The oil is too thick to flow through the jets alone and will eventually clog up the works.

The reason I asked about the model is that the practice is pretty low risk with a single carb, premix engine and leaves the carb bowl pretty much empty. That is why the practice began back in the old days when almost all outboards were single carb and used a very oil-rich premix.
 

khoi30

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Nov 1, 2006
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Re: Yamaha O/B (?)

Thanks for the info. It was very helpful. I will leave the gas line hook up. Thank you again JB.
 

Ray Neudecker

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May 25, 2004
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Re: Yamaha O/B (?)

Ancient Mariner, the oil does not ever go into the carb on a Yamaha oil injection. That is one of the beauties of the system. The oil is injected behind the carb into the intake.
Once the engine stops because of running out of fuel, the oil injection will stop, but while it is slowing down it is still injecting oil into the intake and crank, but not into the carb.
Makes it hard to understand how there can be harm from running it dry of fuel before putting up.
A major part of the service buisness is repairs where the carbs have to be cleaned because the engine set up with fuel in them. Another major part is rebuilds due to the same problem.
Year after year of seeing the results from both ways makes me as a user much happier to run the fuel out before putting up.
 

JB

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Re: Yamaha O/B (?)

Thanks for the correction, Ray. Not expert on Yammys.

I still would rather drain the carbs before long term storage and leave the fuel in them for short term.
 

deejaycee_2000

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Re: Yamaha O/B (?)

Ray said:
Ancient Mariner, the oil does not ever go into the carb on a Yamaha oil injection. That is one of the beauties of the system. The oil is injected behind the carb into the intake.
Once the engine stops because of running out of fuel, the oil injection will stop, but while it is slowing down it is still injecting oil into the intake and crank, but not into the carb.
Makes it hard to understand how there can be harm from running it dry of fuel before putting up.
A major part of the service buisness is repairs where the carbs have to be cleaned because the engine set up with fuel in them. Another major part is rebuilds due to the same problem.
Year after year of seeing the results from both ways makes me as a user much happier to run the fuel out before putting up.

You couldn't have said it any better .... don't you just love a yamaha ... :)
 

Ray Neudecker

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Re: Yamaha O/B (?)

Yes the carbs do have drains, but it is not considered eviromentally correct anymore to just drain them out.
There are actually race sites now which do not allow you to drain the boat on the ramp much less the carbs.
 

yamamarinetech40

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Dec 17, 2006
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328
Re: Yamaha O/B (?)

I have to eat fellas, if he doesn't wanna drain the carbs, i say that's OK....o:)
 

Ray Neudecker

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Re: Yamaha O/B (?)

I hear you, there would be a lot of shops having to close if every one drained their carbs and manitained the fuel system.
 

JUSTINTIME

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Sep 2, 2006
Messages
3,284
Re: Yamaha O/B (?)

Ray said:
I hear you, there would be a lot of shops having to close if every one drained their carbs and manitained the fuel system.


funny u say this
the rumor is that the dealers will no longer will be able to sell factory manuals for the new up coming motors to the customer, this will force them to take it to a shop
 

zzzzz

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Jan 13, 2003
Messages
1,094
Re: Yamaha O/B (?)

down here we offer the "snowbirds" the option- an hour's labor to put it to "sleep" and an hour's labor to "wake" it up.......it's still cheaper than a carb job8)
 

ted655

Petty Officer 1st Class
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Oct 21, 2003
Messages
252
Re: Yamaha O/B (?)

And if the injection system has been disconnected? We are back to running dry cyls, right.
Boating is nearly year around here. I Sea Foam or Stabil my built-in tanks year round. No more than 4 weeks pass between use. Hope I'm doing it right. ???:$
 
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