1989 Yamaha 40hp advice...

N1265

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Hi guys,

I took my new to me '89 Yamaha 40 hp motor ( witch sat for seven years, after being professionally winterized ) to a marina to have them look at it. They said the compression was good, ignition was good and the crank case held pressure fine and was passing water fine. However they were unable to keep it running without choking the motor and said the carbs need rebuilt and inspected, they want $400. to do it.

My first question is : Is this a fair price ?

My second question is : is it hard to do it yourself ? I am sure I could handle cleaning and rebuilding them, But have no clue what to expect in setting them up
( my motor has 3 cylinders )

Many Thanks.
 

99yam40

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Re: 1989 Yamaha 40hp advice...

Pick up a Yamaha service manual for your motor and read up.
It is not hard to do, but if you never worked on a motor or carb it is not something we can say you can do without knowing your mechanical ability. Set up is in the manual
 

N1265

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Re: 1989 Yamaha 40hp advice...

Many Thanks...
 

seaox20

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Re: 1989 Yamaha 40hp advice...

Hi guys,

I took my new to me '89 Yamaha 40 hp motor ( witch sat for seven years, after being professionally winterized ) to a marina to have them look at it. They said the compression was good, ignition was good and the crank case held pressure fine and was passing water fine. However they were unable to keep it running without choking the motor and said the carbs need rebuilt and inspected, they want $400. to do it.

My first question is : Is this a fair price ?

My second question is : is it hard to do it yourself ? I am sure I could handle cleaning and rebuilding them, But have no clue what to expect in setting them up
( my motor has 3 cylinders )

Many Thanks.
I have an '89 yamaha 200 and i just cleaned the carbs. i went to discount auto parts and got the gallon jug for carb soaking. It was $23 and i let each carb (with bowl off) sit for about 30 minutes... It cleaned inner and outter carb great. My motor does not have carb issues after that. A good price would be $2-$300.00 to rebuild and clean them...prob cheaper seeing how you only have 3.....keep it in the water seaox20 out
 

N1265

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Re: 1989 Yamaha 40hp advice...

Well I got the carbs off and cleaned up today, After reading other threads where people have re used the gaskets, I am wondering if there is anything you use to clean the mounting gasket up with ? It is not ripped or torn but it does have some white residue
( looks like oxidation of some sort ) on it.

Do you guys just wipe it down and re use it ?
 

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Re: 1989 Yamaha 40hp advice...

I would be lying if I said I have never reused a gasket, but it is frowned upon and you are asking for trouble if you reuse. As far as the price, it is a fair price considering that they will check idle and wot timing and perform sync and link and hopefully replace fuel pumps. But what you need to realize is once you get your boat running and carbs cleaned, take percautions. Run fuel stabilizer all the time, because the one time you don't is going to be the one time "Murphy" pays a visit.
 

N1265

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Re: 1989 Yamaha 40hp advice...

Ok,

I got the carbs cleaned up and re mounted and now I am reading the manual on how to set the idle,

My question is : can I use an automotive tach, set it to 6 cyl and X2 the reading to get the correct RPM for the 3 cyl outboard ?
 

99yam40

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Re: 1989 Yamaha 40hp advice...

I do not think that it would work. most automotive tachs did not run off of the charging system like the outboards
 

N1265

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Re: 1989 Yamaha 40hp advice...

what about one of those fancy timing lights that have the tach built in, That take the reading from the #1 plug wire ?
 

99yam40

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Re: 1989 Yamaha 40hp advice...

probably should work if there is not to much interference from the other plugs firing
 

N1265

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Re: 1989 Yamaha 40hp advice...

Hi guys,

I posted a couple of videos on you tube of how my motor is currently running, I am not sure if I have the carbs adjusted right. the SELOC manual is hard for me to understand because I am not sure if the section I am reading is the actual section for my motor. ( the book covers 2-250 HP ) It is a 1989 40HP model number 40 ELG

The static timing is currently set at 6 DEG ATDC on the full retard stop and 28 deg on the full advanced stop, ( I believe this is the correct settings for this motor )


I am concerned with the gap ( currently .040 ) between the throttle cam and the throttle roller and the amount I have adjusted the pilot screws ( The book calls for 7/8 to 1 3/8 ) turns but I had to turn them out 2 1/2 turns to get it to run decent.

Let me know what you think.

http://www.youtube.com/watch?v=Y7_cKORq2iQ

http://www.youtube.com/watch?v=vefzFqIW-a0
 

99yam40

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Re: 1989 Yamaha 40hp advice...

If it will not run properly with the setting as shown in the specs then you need to re clean the carbs as there is some problems still with them
 

N1265

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Re: 1989 Yamaha 40hp advice...

Do you know if the the 1 1/8 setting for the pilot screws are the right settings for this motor ? I just want to be sure that's where they need to be before I take them off again ....
 

99yam40

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Re: 1989 Yamaha 40hp advice...

my 1999 C40TLRX calls for 1 1/2 +/- 1/4
no idea if your 1989 is the same or different

I like the Yamaha service manuals as they are not so confusing, they cover your motor not all of them
 

N1265

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Re: 1989 Yamaha 40hp advice...

Where can I get the Yamaha service manual ?
 

99yam40

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Re: 1989 Yamaha 40hp advice...

From Yamaha or ebay for something that old
 

N1265

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Re: 1989 Yamaha 40hp advice...

Do you guys dip the carb bodies when cleaning ?
 

N1265

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Re: 1989 Yamaha 40hp advice...

I took the carbs off again to clean them and I noticed some numbers on the main jets. The top and bottom carbs were # 115 and the middle carb was #120.

Is this normal ? or an indication of a mistake on a previous tear down ?
 

99yam40

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Re: 1989 Yamaha 40hp advice...

Should be correct , you can look at the parts break down and make sure.
My 1999 C40 has #118 instead of #120 on middle carb with #115 on the other 2
 
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