tell me about the poppet

[150BlackMax]

Hi..love IBoats!!

I have a 89 150 BlackMax Merc that likes to overheat (horn goes off) when it's in that fast idle-not yet on plane speed...on plane engine is fine. Temp gauge is non-marked with numbers...replaced impeller and whole housing, stats, and poppet. I haven't run it till the horn has gone off since replacing all the parts, but the temp gauge does still like to climb...

I guess my question is, is it possible to screw up installing the poppet valve? How tight does that screw on top of the valve need to be? Could I have overtightend it or something?

 

[ronnieboy]

Re: tell me about the poppet

mercury says should be at least 6 to 7 pounds seat pressure, seal the water tube, ron

 

[150BlackMax]

Re: tell me about the poppet

Which tube..the short plastic one from the pump housing or the long on that goes into the powerhead?

 

[andy6374]

Re: tell me about the poppet

Did you replace all the components of the pressure relief system (poppet assembly)? It could be that the spring behind the poppet is old and stiff and isn't allowing the poppet to open until higher RPMs/water pressures.

 

[150BlackMax]

Re: tell me about the poppet

Yeah, I replaced everything but the top cover...is it possible to screw up re-installing the thing? I had the little diagram and put it back in like it said..the question I had was (let me remember)..there was a screw that went through a gasket or something that screwed into the plastic valve thing (the poppet?)..It was hard to screw in, don't know if I didn't do it enough, or too much, etc...overheat only happens at that no wake zone fast idle speed...idle is fine, on plane is fine.

 

[Laddies]

Re: tell me about the poppet

Max, did you run a bead of RTV on the top of the divider web that seperates the exhaust and water pump cavitiies, Mercury recommends it on V6 engines

 

[150BlackMax]

Re: tell me about the poppet

Max, did you run a bead of RTV on the top of the divider web that seperates the exhaust and water pump cavitiies, Mercury recommends it on V6 engines

I didn't use rtv on anything, and I don't know what a divider web is.....help!

 

[Laddies]

Re: tell me about the poppet

Actually, the manual says silicone seal. The exhaust divider plate is the web that is right behind the water pump cavite and the purpose of the divider and sealing it, is to keep exhaust from ventilating the pump as the boat goes on plane

 

[150BlackMax]

Re: tell me about the poppet

I'm still not picturing this...is this the place where the pump housing sits in the lower unit? There's like a depresssion, then some gaskets and stuff go in, i think, then that shiny silver base that the impeller sits on, the the impeller, then the housing then o ring, right?

 

[Laddies]

Re: tell me about the poppet

Yes the depression you are talking about is formed by the exhaust divider the is the web between the w/pump and exhaust cavity

 

[ronnieboy]

Re: tell me about the poppet

the watertube is the 1/2 in or 5/8 copper tube running from the lower unit into the power head, has to seal or will let pressured exaust gas into the cooling stream, not good, ron

 

[150BlackMax]

Re: tell me about the poppet

the watertube is the 1/2 in or 5/8 copper tube running from the lower unit into the power head, has to seal or will let pressured exaust gas into the cooling stream, not good, ron

So seal it at the junction of the plastic tube out of the waterpump housing where it meets the watertube, or where the watertube goes into the powerhead? Is this standard merc operating procedure, or something that fixed a problem that you had?

 

[ronnieboy]

Re: tell me about the poppet

it fixed a 3yr old problem i had, but seal the water tube in the powerhead or dis assemble and install new seal RTV is fast er and works. bottom usually doesnt leak , i doubt merc would aprove, hahhahahahah ron