yamaha C40 ELRR pressure control valve

[sabsab]

Gentleman, can I install a mushroom type pressure control valve on my C40 ELRR Yamaha. I ran in salt water and flush my outboard after every use but am wandering is maybe the new type pcr might work better, that is keep it from sticking open or closed.

[boscoe99]

Is there current a problem with the existing pressure relief valve?

Yamaha has not replaced the original valve in your motor and must think the original one is doing the job for which it is intended.

But I like experiments. Buy one of the newer style valves, install it, and let us know what you see.

[99yam40]

Are you saying there is a PCV on the Yamaha 40?

I have never found one on a motor that small and I have a C40

[boscoe99]

Item 29

1993 C40ELRR Yamaha Outboard CYLINDER CRANKCASE Diagram and Parts

[Sequoiha]

Yes you can use the new button type PRV, I change the old style out every time I service one.

[99yam40]

I guess they decided somewhere down the line that the PCV was no longer needed in the smaller motors ,
I learned something new already today, so now I can just coast the rest of the day.
I think I will go fishing

[boscoe99]

I guess they decided somewhere down the line that the PCV was no longer needed in the smaller motors ,
I learned something new already today, so now I can just coast the rest of the day.
I think I will go fishing

Remember, just cause one model Yamaha is configured one way does not mean that the same model Yamaha will be similarly configured. Either Yamaha can't figure out how they want to be constructing a motor or they like to keep the user community confused.

A part called a CDI is a CDI is a CDI. Or, maybe it is not.

Let's tell everyone that an O2 sensor is the greatest thing that has ever been used in a Yamaha. Then, stop using it.

Let's use a knock sensor in most big block motors. But oh, let's not use it in a big block HPDI. How well did that work out for Yamaha?

Bout the only thing that one might surmise about a Yamaha is that it will be painted gray. But, don't bet on it.

[boscoe99]

Yes you can use the new button type PRV, I change the old style out every time I service one.

What changes do you see with the new style poppet?

[sabsab]

Thanks for your reply. I will try one and report back.

[Sequoiha]

What changes do you see with the new style poppet?

I've never seen the new one get stuck open or closed.

[rodbolt17]

never saw the new design stick.
I have seen the new design wear out which never happened with the old design.
properly maintained I prefer the old design.

but if your not gonna do the maint it really doesn't matter.

[boscoe99]

What symptoms would you Yamaha mechs expect to see if the valve stuck closed on a C40?

[sabsab]

Thanks for your reply. I will try one and report back.

Gentleman, Looked to see if there was a specific spring and mushroom poppet valve for a 1993 Yamaha C40 and the only ones I could find was Valve # 60H-12416-00 and spring # 90501-16m11. Here is picture of spring and poppet valve. The bottom spring is the orginal one for my motorl. Big different. Definitely not for my motor. Guess I will leave well enough alone. IMG_0633.jpg

[rodbolt17]

the 60H is the supercession of the original.
replace it if it makes ya warm and fuzzy.
or buy a new grommet carefully clean the grommet pocket and roll.

if the control valve somehow stuck shut you would have a serious tell tale stream and possibly blowing the hose off the tell tale restrictor.
stuck open the normal complaint is overheat at idle.

same as when the new design wears the face off.

[boscoe99]

Gentleman, Looked to see if there was a specific spring and mushroom poppet valve for a 1993 Yamaha C40 and the only ones I could find was Valve # 60H-12416-00 and spring # 90501-16m11. Here is picture of spring and poppet valve. The bottom spring is the orginal one for my motorl. Big different. Definitely not for my motor. Guess I will leave well enough alone. [ATTACH]2097[/ATTACH]

A C40ELRR calls for a 90501-14M02-00 spring and a 663-12416-00-00 valve, both of which are still available from Yamaha.

1993 C40ELRR Yamaha Outboard CYLINDER CRANKCASE Diagram and Parts

Where did you come up with the part numbers that you have listed?