Difference between Yamaha 2 stroke outboard years.

[Christian.T]

Hello!

I`ve got a 40Hp 2 stroke 1993 mod engine which i`m very pleased with, considering this is my first boat.

I was wondering about part compatibility with older and newer two strokes.

My goal is to look out for a 50HP with trim-tilt with a busted powerhead or the lower underwaterhouse? (Direct translation from Norwegian ) I`ll exchange the carburetors, exhaust manifold(?) and shaft(in order to get the trim tilt function?).

If i found a 1986 with these things, or a 2003 with these things, could i work on it or won`t that work at all?

What is the main difference between the different models (exluding decals of course).

I could always save up more money and just upgrade my engine to something like a F50, but that will easily cost me 1500-2500 depending on the year on the engine, while a damaged Yammie 50 2T would cost something like 4-800$ and i could sell the parts i don`t need.

Hope that you don`t laugh of my English capabilities, at least i try. ^^

Best regards,
Chris!

[99yam40]

Look up at the top of page and click on the red Purchase yamaha parts and look up your motor on this web site.

If you click on a part it should give you at the bottom of the page, all of the motor models that that part will fit.

Maybe this will help you figure out what can be used on the different years.

You do know some have different numbers of cylinders over the years (3 and 2)

[ausnoelm]

Not exactly sure why you would change the carbs, exhaust and "shaft" to fit power trim?

[Christian.T]

Look up at the top of page and click on the red Purchase yamaha parts and look up your motor on this web site.

If you click on a part it should give you at the bottom of the page, all of the motor models that that part will fit.

Maybe this will help you figure out what can be used on the different years.

You do know some have different numbers of cylinders over the years (3 and 2)

Yeah, i was thinking of the "same" engine though all the way down, the 3 cyl version.

From the pics i can`t see the difference between a 2003 40HP 2 stroke and a 1991 40HP 2 stroke (Excluding paint/emblems, both are of course 3 cyl) so i was wondering why i can`t use 2001 carbs, or trim-tilt on my 93 Yamaha 40HP? I haven`t checked up the part(s) number(s) though.

I was also wondering what the actual difference is, as if you got two engies, one 15 years newer, will you notice a big difference is performance, fuel consumption, speed etc?

@Ausnoelm: Not exactly sure why you would change the carbs, exhaust and "shaft" to fit power trim?

Hi! Not for the trim-tilt, but to get 50HP. The 40 and 50 are the same block (698CC) and the difference is plugs (higher warmvalue?! Directly translated, excuse me ) carbs and exhaust plate/manifold.

So i want to look for a defective 50HP with trim tilt in order to do a big, relatively cheap upgrade.

Thanks a lot for your answers!

[Christian.T]

Bump!

I was wondering about a Yamaha tach i`ve bought. It got no option to choose 6/12 pole etc. Does it do that automatically?

It`s one of these :New Yamaha Digital Multifuntion Tachometer 1994 2004 6Y5 8350T 83 00 | eBay

On the back of mine though it stands "3YP"

[boscoe99]

Bump!

I was wondering about a Yamaha tach i`ve bought. It got no option to choose 6/12 pole etc. Does it do that automatically?

It`s one of these :New Yamaha Digital Multifuntion Tachometer 1994 2004 6Y5 8350T 83 00 | eBay

On the back of mine though it stands "3YP"

It does have an option to changes pole settings.

It does not do it automatically. Manual change is needed.

[Christian.T]

It does have an option to changes pole settings.

It does not do it automatically. Manual change is needed.

Yeah, it only shows half of my RPM (So i`m guessing it`s on a 12P setting, while my engine is 6P?) because 400 RPM idle seems very low. ^^

Would you be so kind to tell/show me how i can change the setting?

[boscoe99]

[Christian.T]

Thank you!!!!

I feel like a noob now, but thanks alot for your help!

Will test the tach again today and see if it works like it should.

It was on 12 pole 4 stroke on the settings, so i changed it to 6 pole 2 stroke as it should be on.

Question: it stands that my total hour is on 397, i don't think a old two stroke has only been used 400hrs?

Is each data stored on the engine itself, or the tach?

[boscoe99]

With your model of motor, no engine hours are stored in the motor. With your tachometer, all engine hours are stored in the tachometer.

Other model motors and tachometers are different.

[Christian.T]

I thought so as my engine is old, will try to get a four stroke next time, as of now i can`t afford it. (I`m 16)

Thanks alot! Will reset the tach and pop in if i got some other questions!

[Christian.T]

Hi again!

I started up my engine and the tach works like it should, many thanks!

But the idle RPM is a tad to high, 1000-1200. And the engine shakes alot (I know it`s a two stroke, but i shake far worse than the 30HP mercury I owned before this)

Does this got something to do with the ignition? I need to "calibrate" it?

The idlke RPM I can change via the ICM, as well as the ignition?

Other than that the motor is flawless, running great, no so much smoke and starts on the first try. :=)

[almetelo]

What motor do you have?

I mean PID and S/N ?

I supose that must be a 40H** PID 6H4

Maybe I can help you...

I had my 1st boat with a Yammy 30 3 cyl when I was 16 and I wish know more about motors on that time...

[Christian.T]

It`s an 40HEO 6H4 - L - 452221

40 is for the engine hp
H is for the model series
E is for electric start
O is for oil injection

6H4 is for the last major engine update? (to the design/block itself?)

L is for long shaft.

So this is as far as I`ve come!

Wish i knew more about motors and boats, i know a lot about pcs, watercooling overclocking etc. Got a 980Ti with my 5960X under water. ^^

But the more i ask and read, the more i know!

[almetelo]

Send me your email by PM and tonight when at home I'll send you the SM and manual parts for your motor.

One of my buddys have a 50DEO 6H5 which is exactly the same motor as yours just diferent carbs