need parts help

[jdarnell0716]

I would like to add electric start to my 4 stroke 40hp manuel start motor model F40MSHD. I know i need a starter,and solonoid and a little help. thanks

[boscoe99]

Mostly you will need money. And some engineering expertise. And at a minimum a starter motor, key switch and some place to mount it, battery cables, starter motor relay, wiring harnesses, etc., etc.

Go to Home | Yamaha Outboards and then on to the parts catalog. Open it to your specific model. Then, look at every illustration and make note of the parts differences between an F40MSHD and an F40TLRD. Ignore the power trim and tilt stuff, and other stuff, which apparently you don't want.

Here is an example of but a few of the items that you may need

Boat Parts: 67C-81949-00-00, 67C-81949-10-00, 6H5-81920-00-00, 67C-81800-01-00, 65W-81941-00-00, 67C-82105-U0-00, 67C-82590-10-00, 65W-81960-10-00

Is the core problem that your motor is hard to start manually?

[jdarnell0716]

yes especially in 32 degree weather.

[boscoe99]

The carburetors in your model can be particularly problematic.

First make sure that the prime start device (automatic fuel enrichment device) is working correctly.

Are you the original owner and has it always been difficult to start? If this is new then maybe the prime start needs to be fixed or maybe the carburetors need to be cleaned and synchronized.

If the prime start device works correctly and the carbs are clean then I would install larger jets. Both the pilot jet and the main jet. I bet the motor will then start and run just fine with but one, maybe two, pulls.

Many an F40 carbureted motor that was headed for the junk yard was saved by installing larger jets. Let's just keep this between you and me. We don't want the EPA police to know.

[jdarnell0716]

yes i am the original owner. if anyone tells you they want a pull start hi compression motor- they are stupid. especially when you get old and the shoulder sockets need grease fitttings. but i will try the automatic prime. thanks

[rodbolt17]

as the carbs on that model actually use accelerator pump plungers try racking the throttle to wot rapidly about 3 times before starting.
starting miust be done with throttles closed.

[rodbolt17]

another thing
the F40 for that year was made by mercury marine and will be the same stuff.
most the manual start models did not have the ring gear for electric start.
if the ring gear is still available it can be added to most the manual start flywheels.

[boscoe99]

as the carbs on that model actually use accelerator pump plungers try racking the throttle to wot rapidly about 3 times before starting.
starting miust be done with throttles closed.

Good point.

Mr. OP, try this. If it lights up more quickly than it normally does then this indicates more fuel is needed for a better start.

[boscoe99]

yes i am the original owner. if anyone tells you they want a pull start hi compression motor- they are stupid. especially when you get old and the shoulder sockets need grease fitttings. but i will try the automatic prime. thanks

Many a small manual start four stroke has brought a big strong man to his knees after having whipped his ass.

[rodbolt17]

if I were king?

no outboards over 8 hp would be allowed to only have manual start, electric start would be mandatory.

at 20 we thought 65hp manual start outboards were cool.
at 52 I cringe at a manual start 9.9.

[almetelo]

Hi Boscoe!

I guess I've read on one of your previous posts that you have rejeted a F40 with F25 jets with good results mainly at cold start...

Have you noticed diference on fuel consumption?
At WOT rev's/rpm's remained the same?

Have a friend with a F40 and this very same "problem"

[boscoe99]

Hi Boscoe!

I guess I've read on one of your previous posts that you have rejeted a F40 with F25 jets with good results mainly at cold start...

Have you noticed diference on fuel consumption?
At WOT rev's/rpm's remained the same?

Have a friend with a F40 and this very same "problem"

With respect to fuel burn, I have not compared an F40 with F25 jets with an F40 with F40 jets.

Fuel flow with the unmodified motor has got to be better given the fact that it may not run at all. Or, people get so fed up with it that they don't want to use it. That saves fuel. But, increases discontentment.

In my case, I put both the pilot and the main jets from an F25 into F40's. Obviously, the fuel burn will be higher but to what extent I cannot say. Did it on seven or eight different motors and in every case the improvement was miraculous. It made a joy to operate what was an almost inoperable motor.

Your friend might just install the F25 pilot jet and see if the improved start, idle and acceleration are satisfactory. He can then try installing the main jet if needed. Let us know the results so we can all learn.

Jets are expensive if purchased from Yamaha. You might want to get some micro drill bits and try reaming out the existing jets. Maybe they don't need to be opened up as much as the F25 jets are. I just had F25 jets and used what I had.

[99yam40]

The jets may have some special shape to the hole, I really do not know for sure, but they warn about putting hard wires through them when cleaning out.

Seems like the smaller 25HP motors jets would be smaller than the 40 bigger one.
more fuel to create more hp

[almetelo]

Thanks Boscoe and 99yam!

I'll sugest you remedy to my friend and we'll see what he decide.

I know a guy with a bike workshop/garage that have specific drills, diferent sizes to rejet jets and that maybe an option (a piece of metal wire in not an option)

There is a site/store in the US selling original Keihin jets for a fraction of the price that yamaha sell them) Just 4 or 8 jets may keep our costums far from the package

Slow Jet F25 #50 F40 #38
Main Jet F25 #112 F40 #95

[boscoe99]

The jets may have some special shape to the hole, I really do not know for sure, but they warn about putting hard wires through them when cleaning out.

Seems like the smaller 25HP motors jets would be smaller than the 40 bigger one.
more fuel to create more hp

Might seem that way but in the case of the F25 the one carburetor is feeding two cylinders. In the case of the F40 there is one carburetor per cylinder for three cylinders.