Another little trick for the 900

river · Oct 12, 2010

someone was asking about this and I dont remember who so I hope you see this its for the exhaust valves on the 900 as they do not stay open a wot and this will make sure they do, see pic you have to drill the two holes and add the seal and you need a dif bellows washer I think its from the 800 polairs the bellows part # 5132950 and the seal part #32431 its a prop shift seal for a boat motor.

BIGGDAWG · Oct 30, 2010

to the top

doing this to our 900's and my 975

xcya · Oct 30, 2010

exh. valves

river said:
someone was asking about this and I dont remember who so I hope you see this its for the exhaust valves on the 900 as they do not stay open a wot and this will make sure they do, see pic you have to drill the two holes and add the seal and you need a dif bellows washer I think its from the 800 polairs the bellows part # 5132950 and the seal part #32431 its a prop shift seal for a boat motor.

What size are the holes? how deep do you drill? do you plug of the lines coming from the top of the valves?

river · Oct 30, 2010

You have to drill the holes so they go thru to where the other outlet is, drill them a little smaller than the stock hole. as when you put the seal in it blocks off the two holes that are there, if you look you will see the the other holes . hope that makes sense , as you can see in the pic I mark a line for where the larger hole go's and that go out the end where you hose hooks up. the other hole go's thru to the one goes out underneath out the bottom if you turn it over you will see where the hole is. you will have to put a small wire in there to find it. if you can't find it let me know I will post a pic of where is it. hope this helps

BIGGDAWG · Oct 30, 2010

we drilled ours today i will take some hi res photos and get them posted working on finding the seals. thanks river

xcya · Oct 30, 2010

BIGGDAWG said:
we drilled ours today i will take some hi res photos and get them posted working on finding the seals. thanks river

yes, please do that, I would like to do the same.

BIGGDAWG · Oct 31, 2010

Here are some pics from our valves we did. one is an 05 and the other is an 06 note the differences in the valves. the drill bit is to show the angle of the second hole. you have to aim for the small original hole and in the other pic you see on the bottom where you are trying to hit.

i will post up more when i get the seals installed

polhiker · Oct 31, 2010

where do you pick up the seal at?

Sxrlar · Oct 31, 2010

Interested in doing this to my buds 900 also, is the seal something that can get picked up at NAPA?

BIGGDAWG · Oct 31, 2010

Sxrlar said:
Interested in doing this to my buds 900 also, is the seal something that can get picked up at NAPA?

i will let you know, i have a couple ordered and need to see what works. then i will post up.

e46m3 · Oct 31, 2010

This is very interesting. I just picked up an 05 900. Please forgive me if this is a stupid question, but what do you gain from this modification? I'm assuming its done to gain a little more power. I am going to take my valves out and clean them check the bellows. I figure if I have them out I should try this mod. Why not do it all at once. Thanks.

BIGGDAWG · Oct 31, 2010

e46m3 said:
This is very interesting. I just picked up an 05 900. Please forgive me if this is a stupid question, but what do you gain from this modification? I'm assuming its done to gain a little more power. I am going to take my valves out and clean them check the bellows. I figure if I have them out I should try this mod. Why not do it all at once. Thanks.

this mod increases the pressure signal to the exhaust valve which helps keep the valves all the way open at wot high rpms. and makes them more responsive.

any questions just ask.

e46m3 · Oct 31, 2010

Thanks.

rmk2112 · Oct 31, 2010

BIGGDAWG said:
this mod increases the pressure signal to the exhaust valve which helps keep the valves all the way open at wot high rpms. and makes them more responsive.

any questions just ask.

How is this different from plugging off both hoses?

BIGGDAWG · Oct 31, 2010

rmk2112 said:
How is this different from plugging off both hoses?

I am also plugging my hoses.

how this is different is it seals the shaft. your shaft is open to the exhaust port through the bushing and it is a loose fit. you loose pressure through the shaft to bushing clearance. by putting in a seal and drilling the holes you have a better pressure signal to the diaphragm making it stay open better at high rpms.

if you are plugging your exhaust valve ports you don't need to drill the hole that goes to that port you only really need the angled hole. i just put it in incase i play with hooking up the solenoid again.

river · Oct 31, 2010

BIGGDAWG said:
this mod increases the pressure signal to the exhaust valve which helps keep the valves all the way open at wot high rpms. and makes them more responsive.

any questions just ask.

very good pic,Biggdawg . and yes these are prone to a WOTwhen you keep it there for a while , the valves will fall down a bit and this will keep them open at wot for as long as you hold it there. you can also get the seal at a boat dealer who sells parts its a seal for the prop.

guidoxpress · Oct 31, 2010

this is a great writeup and great pics...

so then if one has their valve plugged already (like me) this is not needed whatsoever then? or would it be worth doing anyways..i dont plan on giong back to the solenoid..

polhiker · Oct 31, 2010

I think you still need to drill one hole,the angle one,if i am not wrong

BIGGDAWG · Oct 31, 2010

guidoxpress said:
this is a great writeup and great pics...

so then if one has their valve plugged already (like me) this is not needed whatsoever then? or would it be worth doing anyways..i dont plan on giong back to the solenoid..

sean here is a pic explaining,

BIGGDAWG · Oct 31, 2010

polhiker said:
I think you still need to drill one hole,the angle one,if i am not wrong

yes you are correct :face-icon-small-hap

Another little trick for the 900

Well-known member

Well-known member

Well-known member

Active member

Well-known member

Well-known member

New member

Well-known member

New member

Well-known member

Well-known member

Well-known member

Active member

Well-known member

Well-known member

Similar threads