1985 Mercury Black Max - Reed Valves

[cssulliv]

What is the best way to go about isolating which reed valves are bad??

Thanks in advance!

 

[j_martin]

Re: 1985 Mercury Black Max - Reed Valves

What is the best way to go about isolating which reed valves are bad??

Thanks in advance!

First check the bleed line check valves and lines. Then pull off the carbs and the reed plate assembly. Flip it on it's face, and take a look.

(edit) Black max means big and black. Above comments are for a V6. Inline is someone elses bailiwick.

hope it helps
john

 

[Faztbullet]

Re: 1985 Mercury Black Max - Reed Valves

What makes you think there is something wrong with them???

 

[beagle9]

Re: 1985 Mercury Black Max - Reed Valves

What makes you think there is something wrong with them???

Hello, I have a problem also, where as my 150 Black Max, "has now grounded up aluminum inside the cover that goes over the carbs". My friend tells me that it is a reed valve gone bad, and that I need to do a compression test now on the cylinders, especially seeing that the valve has disentigrated as it did, and was found outside of the engine in the place that it was found.

How hard is it to replace the reed valves on this motor? Are they in the intake just behind the carbs ? Is the material of the reed valves, made up of a material that if enters the cylinders, would it win the day over the materials that make up the cylinders or pistons?

During the compression test, should I remove all the plugs, in order that the motor spin more freely while checking each individual cylinder ?

Thanks beagle

 

[1nebel0]

Re: 1985 Mercury Black Max - Reed Valves

Beagle, when you eat a reed kiss that cylinder goodbye if you are using stock steel reeds.. I have changed the reeds on all my engines over to fiber reeds..if they break they go through the motor harmlessly.. I just bought to sell a 2006 Optimax 225 in mint condition except for one thing..Bass boat that it was on came out of the water over spun the motor, broke two reeds and took out the cylinder..say goodbye to a $18000 motor..to repair it would cost $4000-$8000 depening on what the shop was going to do.. I am going to rip it apart, sleeve the cylinder, put a new piston, re-ring all the other cylinders and sell the motor as a rebuilt motor..Anyways, that's what happens to factory metel reeds..Check out Chris Carlson reeds...Boyseens are over rated...Reeds sit right behind the carbs and are easy to replace.. I am no mechanic however outboards once you understand them are not hard to work on...Lastly, all plugs must be out to get the cranking speed out of the motor...you need to ground all spark leads or risk destroying the ignition systems...

 

[Chris1956]

Re: 1985 Mercury Black Max - Reed Valves

Reed valves are stainless steel. It would be surprizing to their remains in the airbox. Reed valves are just under the intake manifold. I recommend you look around for the real cause of the powdered aluminum in the airbox.

 

[Chris1956]

Re: 1985 Mercury Black Max - Reed Valves

One more thing, Stainless steel reed valves almost never break.

 

[j_martin]

Re: 1985 Mercury Black Max - Reed Valves

I don't think they are stainless. For one thing, most stainless steels work harden and get brittle when flexed repeatedly.

They don't break very often, but when they do, they don't digest very well and usually do some serious damage before they get to the exhaust chest.

The best way to check them is to pull the whole durned reed plate and look at them. If you're that serious about engine tune, you already have the carbs off. It's one more gasket and a dozen bolts to get the reed plate off.

While the steel reeds are really tough, the aluminum reed blocks wear with age and the reed sealing at slow speeds can make idle uneven and irregular. Steel reeds take quite a bit more pressure to open than fiberglass reeds, and that contributes to the uneven or ragged idle.

I removed the 20 year old steel reeds from my XR4, hand lapped the reed blocks flat, and installed a set of Chris Carson sport reeds. I'm really amazed at how nice this thing runs, especially at idle and just off idle. It was always a little ragged and loaded up in a short time. Now it acts like it's supposed to. As always it runs like a scalded dog at WOT.

 

[1nebel0]

Re: 1985 Mercury Black Max - Reed Valves

In regards to steel reeds not breaking go ask the local merc shop how many opti's they see blown up due to reeds or air injectors...While they last a long time, why would you wait for them to go before changing them out and get a better performing motor and never risking losing a motor because of a reed..everybody has their opinions............

 

[j_martin]

Re: 1985 Mercury Black Max - Reed Valves

While I was looking for that last bit if sweetness in engine tune, the key factor in my decision to go with fiberglass reeds was wondering just now long steel reeds could flex a hundred times a second before something breaks.

The 20 year old reeds I took out looked perfect. It took a couple of hours to lap the blocks after 20 years of steel slapping them. New reeds went in picture book perfect and run real nice.

 

[beagle9]

Re: 1985 Mercury Black Max - Reed Valves

Yes, we are somewhat hopeful that the shavings are something that somehow got into the box as an external issue, but we don't see any way possible at this point for that to have happened, so we think that these shavings came from inside the motor. If not the reeds maybe, then what else could cause alluminum grounded up shavings to be in the bottom of the carb cover? Any other ideas or thoughts maybe? The two upper carbs seem to be free of debris and/or shavings, but the bottom carb has some specs of these shavings just inside or around the ventura openings (i.e. where the shavings were laying), however those shavings are not way up into the carb as is observed when looking deeper at it, they just appear around the inner rim of the carb opening at this point. Havn't had the time yet, but will go farther by removing these carbs, and then looking at the reeds next.

Thanks for your time on the issue..

 

[beagle9]

Re: 1985 Mercury Black Max - Reed Valves

Thanks, the boat was taken out by a few friends of mine, and they said that it would not get over 10 knots in the water or even throttle up when attempted to throttle it up, where as then they said that it quit on them next, so they had to run it back in on the trolling motor..

When checked out next, this is what we found..

 

[beagle9]

Re: 1985 Mercury Black Max - Reed Valves

Reed wasn't the problem after all, and upon further investigation. It was the rod and piston that was found oozing out of the carb in a grinded up state. Removed the intake where the reeds were, and behind this was a piston pin, needle bearings and more grinded up alluminum... This motor is toast... It apears that this motor may have suffered from running with no oil, as the top tank on the motor was empty when removed the engine cover. I think the motor was just a time bomb waiting to explode.

It was ashame to have found this, as this motor looked as if it was a hoss when it was right once upon a time, I guess this is what one gets when buying used.

 

[j_martin]

Re: 1985 Mercury Black Max - Reed Valves

Reed wasn't the problem after all, and upon further investigation. It was the rod and piston that was found oozing out of the carb in a grinded up state. Removed the intake where the reeds were, and behind this was a piston pin, needle bearings and more grinded up alluminum... This motor is toast... It apears that this motor may have suffered from running with no oil, as the top tank on the motor was empty when removed the engine cover. I think the motor was just a time bomb waiting to explode.

It was ashame to have found this, as this motor looked as if it was a hoss when it was right once upon a time, I guess this is what one gets when buying used.

Pray tell, exactly who ran it without oil?

 

[beagle9]

Re: 1985 Mercury Black Max - Reed Valves

Can't get a straight answer out of no one yet on that one... smile

 

[j_martin]

Re: 1985 Mercury Black Max - Reed Valves

Can't get a straight answer out of no one yet on that one... smile

You got that one right.

You'd think the owner of the boat would have the oil system set up right, and 3 gallons of oil in the boat tank, which would cover 150 gallons or more of Gas.

Naw, it was defective when bought.

 

[beagle9]

Re: 1985 Mercury Black Max - Reed Valves

Yep, it was toast when purchased... Oh well it's all over now.. Thanks for all your help..

 

[aussieflash]

Re: 1985 Mercury Black Max - Reed Valves

Lesson #1, never buy a boat that doesn't have oil topped off,cause when you drive it the engine will blow......OR you could just put some oil in,then it won't blow.lol.
Definitely toast when ya bought it.