1998 Mercury Outboard 150 MIDRANGE ISSUE - Watch VIDEO , PLZ Help!!!

[hunter200524]

Are you running a mercury fuel line? That black stuff is most likely either the primer bulb falling apart. Or it could be the check valves in the fuel pump diaphragm. Im not exactly sure when they quit using the rubber and plactic valves. But it doesnt hurt to do a fuel pump diaphragm anyway. Sorry I didn't see last night that your idle jets were plugged. That would cause a running condition at midrange also. Make sure to blow throw all orifices with carb cleaner and compressed air.

 

[Ant-Knee]

Are you running a mercury fuel line? That black stuff is most likely either the primer bulb falling apart. Or it could be the check valves in the fuel pump diaphragm. Im not exactly sure when they quit using the rubber and plactic valves. But it doesnt hurt to do a fuel pump diaphragm anyway. Sorry I didn't see last night that your idle jets were plugged. That would cause a running condition at midrange also. Make sure to blow throw all orifices with carb cleaner and compressed air.

Yes, I ordered all mercury fuel lines, Fuel Lines and all the bleed lines...
I have had the motor for a few years now and I do not know when they were changed last..
I never messed with them since they look good, never noticed the black coming off them till now so better to be safe then sorry..
The primer bulb is fairly new...

When I pulled the carb bowls off the carbs, they did not really look that bad but I did notice the black residue in there..
Like I stated earlier I just rebuilt them so I did not think they would have been that bad, Only thing I really noticed in the carbs were the jets were plugged up...

Well all my fuel lines will be here bye Friday, Will get it all back together and try her at the ramp once again...

Will post back shortly guys...

Again thank you all for your help!!!


Ant...

 

[Ant-Knee]

Here is a little video of how the carbs were taken apart and cleaned...
All orifices blowed out with compressed air and soaked for 24 hours in Acetone..
Each carb was done in the same manner, Also checked all jet sizes and they are as they should be...


https://youtu.be/umDCf5ehdKc

 

[Ant-Knee]

Hello All,

Just a little update, It is Sunday and I have received all the fuel lines that I ordered, Except I did not get the bleed lines yet.. There was a delay with the mail, But will be here Monday..

Quick question , On the power pack side of the engine, the bleed lines run under/behind the power packs, Can I just unbolt the entire bracket that holds the 2 power packs for enough clearance to get to the bleed lines? Just looking for a little insight b-4 I pull parts I don't need to...

Thanks guys,

Ant...

 

[Ant-Knee]

Just wanted to update you guys...

Got everything all back together,


Rebuilt carbs ( Double checked all float levels and all passages )
New water separator filter.
Changed all the bleed lines,
Changed all the fuel lines, ( From tank to carbs)
Put 2 new inline fuel filters ( one After water separator and other after the fuel pump)
Fuel will come from tank, then thru the water separator, Thru fuel filter, Thru primer bulb, Thru fuel pump, Thru filter again, then to the carbs..


All the lines were changed with mercury/quicksilver brand..
I am going to run a few gallons of gas oil mix with some sea foam in it prior to taking it down to the ramp for a test...
I will be amazed if this takes care of my issue, But if not I will know for sure it is not in the fuel system...

Thanks again all,

Will update and post another video when I test it at the ramp...

Ant...

 

[Chris1956]

Those inline fuel filters could cause a fuel restriction or leak air into the fuel system, both are very bad. Since the water separator already contains a fuel filter, the inline fuel filters are redundant. I would recommend you remove them.

 

[Ant-Knee]

I have to say, I kind of agree with you.. I will just run the separator then..

I say that cause when I took the one off that was on there b-4, I cracked it open and it seemed to be spotless.. I guess the separator caught anything before the inline filter
and the tank should be clean as I drained and cleaned that year and a half ago...


Thanks for your input,

Ant...

 

[Ant-Knee]

Hello All, Once Again,

Well Like I previously said, boat is all back together, I decided to say the hell with it..I am going fishing...
So Yesterday morning about 4Am my buddy and I headed to the ramp and launched as normal.... I didn't try to test it as I wanted to go fishing..
Just didn't want the disappointment...

Well I have to say I believe the boat is fixed..

I was able to troll at 1800-1900 RPMs, Was never able to do this before..
Boat ran and sounded awesome...

There was some hesitation here and there but I think that is do to not doing the sync / lync yet... The small issues
I did have I am pretty sure it is just adjustments and fine tuning...

I am gonna do the sync / lync and try to adjust carbs better after the holiday....
I am not very good with adjusting / tuning carbs, think I am tone def...


Whats the best way to get the carbs adjusted dead on??


Thanks guys,

Ant...

 

[lprizman]

subbed,,,great info here

 

[scamp12]

That ethanol. Eats that rubber up . Run some fuel additives. That helped with that break down . that ethanol. Absorbs water and settles in the fuel tank and carbs. .

 

[Ant-Knee]

Yes, I am going to run additives for now on...
I should be good to go for a little while now, I HOPE...


Thanks,

Ant...

 

[Ant-Knee]

Hello Again All,

The problem is not fixed.. Same exact issue..
I tested for a short time before and thought all was good, I was wrong..
Had 2 outboard mechanics look at it, And they could not find anything wrong with it.. They didn't even charge me... How often does that happen..
Took it to a 3rd outboard mechanic, He was really good , I THINK.. Him and I went over everything, Redid the sink & link, Got everything set to spec
he charged me a hundred bucks, Said engine is strong, Go out and go fishing, So I did, And the same thing...
So I called him on the phone this morning and told him it is not fixed.. he said it is not the stater because the stater controls High & Low, He said if stater was bad it would not idle or
run at top end, One or the other, so that rules out the stater, He also ruled out the trigger for one other reason forgot what it was But I tested those a while ago and the trigger and the stater both passed there test and I also I switch power packs around to eliminate them...
He says it is a fuel problem, I hate to say it but I agree with him...

He said since we just set everything to spec, Go down to the dock and try adjusting the cam roller where it meets the carbs, it is either getting to much fuel or not enough fuel at that point of throttling up.. Well I am gonna try what he said and I will report back with what I come up with... All I know is I am tired of fighting with this issue...

Well If anyone else has any advice or any other solution, Please let me know...

Thanks all,

Ant...

 

[Faztbullet]

Try backing the roller off the cam leaving a 3/16 gap and retest.

 

[Ant-Knee]

Yes, That's what I am gonna do... he said work it both ways either a little more or a little less and see if that does it..
I really hope this works.. I will report back after next testing

Thanks,

Ant...