Need help with this 88 blackmax

[yorkserv]

I have a 1988 200hp mercury on a 20' mako Just last weekend i was on my way out and the engine went from one second to another from 5000 rpm to 3900 i thought it might of been the primer bulb at the time but as i got further into the day i noticed that when i would get out of WOT to a light idle the engine would bogg out i would restart it and it would cut out unless i gave it some throttle right away.... I tried squeezing the buld while i was about 3/4 throttle to see if i could get the RPM back but not much of a difference I really need some Pointers and Specs on Pressures as far as compression, fuel pressure, etc. Has anyone ran into a problem like this and if so what did you find????

Also in the winter i rebuilt the carbs ( motor is running more on the rich side than lean) changed spark plugs, i never really got into the engine further than that. I had about twenty gallons left in fuel tank that is about four months old and added another fourty on sunday of last week. I do not mix oil into fuel i use the oil injection system on the engine... Also any feedback on the oil injection system on these bad boys.

Tomorrow Morning I am pulling the spark plugs to see if there is a fould out plug, also going to check fuel pump to see if there is any internal failures with it. If you need any more info please let me know more feedback the better

Thanks

York Serv

 

[j_martin]

Re: Need help with this 88 blackmax

I've had a lot of trouble with my 150 XR4 in the fuel area. I wound up putting in a RACOR fuel filter/water seperator, chit canning the thumb sized thing that murkery puts in the motor, and also chit canning the whole bayonet connecter and routing the line into the motor. All of these things showed improvement on a gauge I installed to check fuel pressure at the carbs.

Don't try to run it if it's getting starved for fuel. It's about the quickest way I know of to burn down that powerhead.

 

[studlymandingo]

Re: Need help with this 88 blackmax

You also may have dropped a cylinder. Go to your local auto parts store and purchase a spark-gap tester (they are very inexpensive) and make sure you have a good strong consistent spark on all cylinders.

It is quite possible you could have a stator issue, coil, switchbox, trigger, or something as simple as a plug wire bad.​

 

[yorkserv]

Re: Need help with this 88 blackmax

Thanks for the heads up i have a water/seperator filter but i think im gonnna like you said chit canning that thumb sized thing to.. But seriously thanks alot

Yorkserv

 

[yorkserv]

Re: Need help with this 88 blackmax

Started to fool with the motor this weekend checking for any loose grounds but with mothers day and all i had limited time if you know what i mean... But oh this weekend is a whole different ball game. and its been raining here every afternoon as soon as i check the spark on this thing i will need some pointers with the process of checking the stator, rectifiers, and the switchboxes ( i heard with the switchboxes the only way to check them is to replace them) and what does a stator go for MSRP.

 

[studlymandingo]

Re: Need help with this 88 blackmax

Check eBay for a new stator; I bought one new in the box (bag actually) for 85.00 last year.

You can check the switchboxes by swapping them for one another or by changing the wires going to the coils to see if your problems move around.​

 

[studlymandingo]

Re: Need help with this 88 blackmax

And on that subject, be sure to look at all of the wires going from the switchboxes to the coils, and the wires from the coils to ground. These will have a tendency to become problematic with age. I've replaced nearly all of mine as they have begun to give problems. You would think I would go ahead and replace all of them at once; I have to say, I've gotten pretty good at doing it on the water from the swim-step though!​

 

[yorkserv]

Re: Need help with this 88 blackmax

Thank you Mandingo warrior ive been looking for extra parts havent come across any stators yet

Thanks alot
Yorkserv

 

[yorkserv]

Re: Need help with this 88 blackmax

With those ground wires they were just corroding off. Yeah its amazing what a person can do to keep that boat going i tell you boating brings the Mcguyver out in us

Thanks i will keep you posted on what i find

 

[studlymandingo]

Re: Need help with this 88 blackmax

I had the corroding ground wires on the coils as well as corroding wires from the switchbox to the coils.​

 

[tashasdaddy]

Re: Need help with this 88 blackmax

no one mentioned backpressure, and lack of, if you are setting you idle on muffs, it has to be set approx 100 rpms, high, as there is no backpressure on the exhaust. then it has to the fine tuned with the motor in the water, it has to run faster out of the water to compensate for the backpressure.

 

[studlymandingo]

Re: Need help with this 88 blackmax

Any luck yet with your situation?​

 

[yorkserv]

Re: Need help with this 88 blackmax

Nope been raining every evening out here it suxs right now its coming down like you see in movies.. i will defenetly keep you guys posted.

I havent adjusted the idle or any other thing on the boat this is just something that came up from one sec to another while i was on the water one day do you think the idle could of lost its setting like that

 

[studlymandingo]

Re: Need help with this 88 blackmax

Man we could sure use some of that rain over here on the other side of Alligator Alley! Serious drought!​

 

[studlymandingo]

Re: Need help with this 88 blackmax

You could have lost the idle stabilizer, I've not had a problem with mine so I couldn't tell you what that would be like.

 

[yorkserv]

Re: Need help with this 88 blackmax

Ok guys I had someone look over the motor and what was going was the following a pinhole was created on the bore of the cylinder, from the cooling jacket into the piston. What is the opinion should i take the motor apart and sell it for parts or try to sell it for what it is. The motor runs really good with the a compression on each cylinder of 120lbs and 100 on the cylinder that has the pinhole. What do i do with this thing I am going to buy a new motor but i really dont want to see Betsy laying some where just rusting away I would love for someone to work with this motor. HHHHHEEEELLLLPPPPp

 

[gss036]

Re: Need help with this 88 blackmax

If you are going to buy a new engine, I would try to part it out, definately would be worth more that way unless you can find someone willing to rebuild after they buy it from you. I have been told the lower units are probably $800.00. Tough decision to make, I haven't been there yet but suspect some day I will be with 1989 200hp Merc.

 

[yorkserv]

Re: Need help with this 88 blackmax

Thanks alot really appreciate it. The lower unit was rebuilt about five years ago just as a precaution. So its in great shape i change the fluid on it every six months.. And the power head i was told you could not re sleave it on these motors if you do its a big ordeal IF i can find some one who resleaves it what do you guys think i can expect the motor to last me approximate I know I know its hard to tell but this is something it only ran with water in the one piston for maybe two hours... I kinda am tight with money right now buying a new house in a month so i need to weigh out my options here