Poppet Valve Kit for 85 Mercury Black Max 150 hp V6

[DKPZ64]

Hi, I am in need of a poppet valve kit for a 1985 Mercury Black Max 150 V6 I cant seem to find the kit I need. The one you listed on here dose not look like mine. Could use some help. My engine s/n is A138750.

 

[Chris1956]

Poppit valves changed a bit over the years. Therefore make sure you get one for you exact year motor.
Looks like they changed the poppit design in 1986.

Crowleymarine has all the parts, but I did not see a kit. You can probably order the poppit diaghram and the gaskets and be OK, unless something else is damaged.

 

[Dukedog]

803062T1.... same one Faz recomended.. tha gasket works with design I, II and III.. (both tha two hole and 4 hole cover). you will jus have part of it (gasket) hangin' out on tha left side of your covers... so it will work with your motor.............

 

[DKPZ64]

Thanks for the reply's guys. Could I get some more help? Took the boat out yesterday first time out with it and the overheat buzzer went off fifteen min into it, had no power WOT not sure what's going on. It has a strong tell tale but is very hot. Not really sure which way and where to start. Any suggestions would be greatly appreciated.

 

[Chris1956]

Did she overheat at engine speed below 2000RPM or above, or both?

The poppit starts working at about 2000RPM, when water pressure is strong enough to open it.

The thermostat cools the engine at about 2000RPM or less. Check them for proper operation. I get about 7 or 8 years on a set, in saltwater.

The water pump impeller cools the engine at all speeds. If your's is older than 5 years or so, it is likely time to rebuild it.

Also, put a torque wrench on the head bolts and check 'em for proper tightness. Those old V6 motors tended to have them loosen over time. Compression leaks into the cooling passages cause overheat.

I also flushed my engine cooling passages this spring. It had some buildup in the cooling passages, that I could feel with my finger in the thermostat holes. Not enough to cause issue, but enough where I did not want any more buildup.

 

[DKPZ64]

Just got new thermostats for it. The one's that were in it was 143* and the new one's are 147*. Is this going to be a problem or do I need to return them and get one's that are 143*?

 

[Chris1956]

I doubt the thermostats are accurate to 4*, so you are fine.

 

[DKPZ64]

Thanks Chris. I think I let it idle to long and it got hot. I have a water pup kit coming but I don't know if that is the problem it has a strong tell tale. I'm just wondering if there is a problem with the poppet valve.

 

[Dukedog]

better question... where did you get 147* stats?..OEM?.. jus curious.. never heard of 'em for a V6?

 

[Chris1956]

A Merc V6 engine should never overheat at idle, if the thermostats are working properly and the waterpump impeller is good. At idle the poppit should be closed, and therefore not part of the cooling system.

Mercury water pump impellers will not pump well at idle if the bottom of the impeller has been damaged. They usually pump fine at speeds above idle.

Replacing the waterpump impeller is always a good idea. Make sure all the parts of the impeller come out. If you are missing pieces, look under the pump base for them.

Replace the impeller, wearplate and the two gaskets as well. Replace the pump cover is she has scratches in the SS cup. Replace the base if it looks melted.

 

[DKPZ64]

better question... where did you get 147* stats?..OEM?.. jus curious.. never heard of 'em for a V6?

They came from promarineusa.com p/n 75692Q2. The package says 143 but on the bottom of the tstate it says 147.

 

[DKPZ64]

A Merc V6 engine should never overheat at idle, if the thermostats are working properly and the waterpump impeller is good. At idle the poppit should be closed, and therefore not part of the cooling system.

Mercury water pump impellers will not pump well at idle if the bottom of the impeller has been damaged. They usually pump fine at speeds above idle.

Replacing the waterpump impeller is always a good idea. Make sure all the parts of the impeller come out. If you are missing pieces, look under the pump base for them.

Replace the impeller, wearplate and the two gaskets as well. Replace the pump cover is she has scratches in the SS cup. Replace the base if it looks melted.

I'm still waiting on the water pump kit, I think it's supposed to be here tomorrow. Do you know how hot it is supposed to run at idle? Like I said before it has a strong tell tale but it is steaming hot. It's around 130*, is that to hot for the tell tale? That's why I'm not sure if it's the water pump or the poppet valve. I appreciate all the info.

 

[Chris1956]

Telltale should be warm at idle and other speeds. 143* or 147* makes no difference. If you can keep your hand under it, is fine.

 

[DKPZ64]

Telltale should be warm at idle and other speeds. 143* or 147* makes no difference. If you can keep your hand under it, is fine.

When I have the muffs on here at my house the tell tale is strong but very hot like 130*. Just got back from the lake and when it is in the lake it has no tell tale and it overheats. Before the buzzer went off I pushed it to wot and it has no power and wants to die. Any thoughts on that?

 

[Dukedog]

you need a water pressure gauge.. it would help with "jus chasin' your tail"..... tha wanting to die could be one or more of many reasons... jmo

have ya done a comp test?