Fix a drilled exhaust Black Max 200 to origional

[H2Ocean]

Hi there I have a black max 200hp that came on a checkmate i bought last year. The origional owner drilled out the lower unit and I believe rejetted the carbs. The engine is fine until I put people in the back and the ports are under water, It then has NO power and will not get up on plane, It is also annoyingly loud. I would like to plug the holes but when I do it will not accelerate. Can someone tell me how to find the origional jet sizes and what else people normaly do when they drill these holes?
I embeded a video from u-tube to demonstrate what has been done although this is not me engine.
http://www.youtube.com/watch?v=2YaNH9jghKA

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[Dukedog]

Re: Fix a drilled exhaust Black Max 200 to origional

If your talking about those two holes just below the cowling thats factory. its not a modification. Thats the way earlier Merc/Mariners are. Its an idle exhaust relief because of tha "buried" tuner at idle..............

It sounds like you have a prop/set up problem when you put a load in tha boat...........

 

[sschefer]

Re: Fix a drilled exhaust Black Max 200 to origional

In order to fix it you first have to find out what was actually done. You have to pull the powerhead, pull the mid and open it up. Once inside you can get an idea of what you need to do. The p/o may have put a modified exhaust tuner on it and drilled the mid down at the bottom. If there's six 3/8 holes on either side he knew what he was doing.

On a 200 the factory tuner is the best your gonna get on an unmoded motor. Drilling the mid does nothing but make more noise. What might be happening is that your engine is running bad to begin with and when you load the boat, because the holes are there, there is no exhaust going out the prop to give you slip. Slip is kind of like a clutch that lets the engine rev higher when starting up and gradually becomes fully engaged as speed increases and load decreases. I think I said that right Heavy boats use vented props to further aid in slip. That won't do you any good with the holes in the mid.


If you decided to tear into it, you'll probably find that the exhaust tube is missing. Replacing the tube and the tuner will run you about 300.00 with seals and gaskets. You can tape up the holes from the outside with masking tape and then pour Loctite 2 part heavy duty epoxy in from the inside to fill the holes.

 

[Faztbullet]

Re: Fix a drilled exhaust Black Max 200 to origional

You can tape up the holes from the outside with masking tape and then pour Loctite 2 part heavy duty epoxy in from the inside to fill the holes.

Please do not do this as it is incorrect, as you will seal the idle relief holes and increase back pressure in the exhaust housing. These reliefs take exhaust and back-pressure in from the front of the adapter plate and route it to the relief ports. To seal these you will need to have it welded from the inside of can. The newer midsections are different as they use a hose to relief pressure thru round port in lower cowling.

 

[coolguy147]

Re: Fix a drilled exhaust Black Max 200 to origional

http://www.youtube.com/watch?v=DleIcwsJpD0

 

[Dukedog]

Re: Fix a drilled exhaust Black Max 200 to origional

Please do not do this as it is incorrect, as you will seal the idle relief holes and increase back pressure in the exhaust housing. These reliefs take exhaust and back-pressure in from the front of the adapter plate and route it to the relief ports. To seal these you will need to have it welded from the inside of can. The newer midsections are different as they use a hose to relief pressure thru round port in lower cowling.

FB, I think hes (sschefer) talkin' about tha base of tha downhousing like tha performance bass without tha can ............D

Also think he got tha "cart ahead of tha horse" Sounded like H2Ocean was refering to tha relief ports...........

H2Ocean says: "The engine is fine until I put people in the back and the ports are under water,"

 

[sschefer]

Re: Fix a drilled exhaust Black Max 200 to origional

Please do not do this as it is incorrect, as you will seal the idle relief holes and increase back pressure in the exhaust housing. These reliefs take exhaust and back-pressure in from the front of the adapter plate and route it to the relief ports. To seal these you will need to have it welded from the inside of can. The newer midsections are different as they use a hose to relief pressure thru round port in lower cowling.

Whaaaaa.. I said nothing about the exhast plate. I'm talking about the mid.. I did this exact procedure to my 135 mid and returned it to stock. You need a stock tuner, seals and exhaust tube. Look in the parts manual.

 

[sschefer]

Re: Fix a drilled exhaust Black Max 200 to origional

His problem is that when he loads the boat up, the upper ports are allowing water to enter the mid. Because the tube is missing and the mid has been drilled down by the lower unit the mid is filling with water and the tuner is submerged. Result... no power.

 

[Dukedog]

Re: Fix a drilled exhaust Black Max 200 to origional

Tha mid fills up ta water level as soon as it hits tha water with or without tha can in it. If tha releif ports are submerging with extra but normal weight in tha back seat hes probably got a set up problem with height and prop. He does not mention any thing about tha holes sschefer is refering to in tha bottom of tha mid. Just tha way I read it.............

 

[sschefer]

Re: Fix a drilled exhaust Black Max 200 to origional

Tha mid fills up ta water level as soon as it hits tha water with or without tha can in it. If tha releif ports are submerging with extra but normal weight in tha back seat hes probably got a set up problem with height and prop. He does not mention any thing about tha holes sschefer is refering to in tha bottom of tha mid. Just tha way I read it.............

I agree, the mid does fill and in his post he mentions how loud it is. In the video's he shows water and exhaust out of the lower mid and say's it's not his engine but one similar.

In order for the exhaust to exit at that point the exhaust tube would have to have been removed otherwise all the exhaust would just go out the prop like normal and the holes would have no purpose and definitely no exhaust.

I think what's happening is that the mid fills to one level when he's unloaded and when he loads down it fills the rest of the way and because there's no exhaust tube, it submerges the tuner. The P/O may have also put an after market tuner on it and it may be running half way down the mid.

You're right he needs to do some adjusting. A hydraulic jack plate might be the cure but it's less expensive to just put the mid back to stock. After all there's no real performance gain in his application, it's just more noise.

It's a toss up as to the amount of work involved for either.

 

[Dukedog]

Re: Fix a drilled exhaust Black Max 200 to origional

Tha only thing I see in tha vid is exhaust and water exiting ta two relief holes just below tha cowling. This is by design and supposed to opperate that way even more so with tha can still in tha mid. They are supposed to be there on tha earlier motors..........

Tha mid IS stock.....................May/may not have tha can removed but tha holes are supposed ta be there.


Think about tha large s shaped hose on tha back of your motor. Tha two slots on your motor should be solid, no holes and more efficent. Thats what replace tha idle relief holes on tha earlier models................

 

[sschefer]

Re: Fix a drilled exhaust Black Max 200 to origional

Tha only thing I see in tha vid is exhaust and water exiting ta two relief holes just below tha cowling. This is by design and supposed to opperate that way even more so with tha can still in tha mid. They are supposed to be there on tha earlier motors..........

Tha mid IS stock.....................May/may not have tha can removed but tha holes are supposed ta be there.

I agree. There are two other videos by the same person that made the first vid. It's to confusing at this point.

 

[Dukedog]

Re: Fix a drilled exhaust Black Max 200 to origional

Where are tha other vids?

 

[sschefer]

Re: Fix a drilled exhaust Black Max 200 to origional

Where are tha other vids?

Go to the link he has posted and after it plays, two others pop up of the same boat. At least they did right after he posted the first time.

 

[sschefer]

Re: Fix a drilled exhaust Black Max 200 to origional

Just went and looked and the other two are gone. There is a pretty sick 150 you could diagnose if you want and another of a guy that doesn't know what the trim button is for.

 

[sschefer]

Re: Fix a drilled exhaust Black Max 200 to origional

I just checked it and the other two are gone now. There's one of a sick 150 and another of a very proud 150 owner who hasn't learned to use the trim yet. And yet another one of someone who's so proud the signed their cowling. Pretty cool.

 

[Dukedog]

Re: Fix a drilled exhaust Black Max 200 to origional

Think I found 'em. Its on a Sidewinder. Its got a cle gearcase and either a HiPerf. bass downhousing or its been drilled tha same way. So hell yeah, its gonna be loud. I don't think tha one in tha video has tha same problem he is having with a load..............

 

[Faztbullet]

Re: Fix a drilled exhaust Black Max 200 to origional

If holes are in mid above the the cavitation plate the epoxy deal will work,(pic of my old mid has them) sorry if I misread...Like DDog said exhaust can has nothing to do with water or exhaust exiting idle reliefs ports, thats why the pictures. From video it looks like a 16ft footer with V-6 ,battery and may have fuel tank in rear and setting way to deep on transom=buried exhaust.

 

[sschefer]

Re: Fix a drilled exhaust Black Max 200 to origional

If holes are in mid above the the cavitation plate the epoxy deal will work,(pic of my old mid has them) sorry if I misread...Like DDog said exhaust can has nothing to do with water or exhaust exiting idle reliefs ports, thats why the pictures. From video it looks like a 16ft footer with V-6 ,battery and may have fuel tank in rear and setting way to deep on transom=buried exhaust.

LOL, I thought we were all thinking alike. Unfortunately we really don't know what his problem is because the boat in the video isn't his. I also noticed that we are the only ones talking in this thread so I wonder if it's even real.