1989 v175 black max poor acceleration and idle

[bsj21]

i bought a 1989 ranger bass boat with this 89 mercury blackmax 175 carburetor motor on it. before i put it on the water yesterday it ran great hooked up to the muffs on the hose. when it was in the lake it did not idle as good and is harder to start than on the hose. in neutral it would rev but not as good as on the hose also. but in gear it would just sputter and bog and then die when trying to accelerate hard or slow. the fuel priming bulb is hard when running. when you hit the enrichment button a few times while accelerating you can get motor to get going. it takes quite a while with the throttle floored and once you break the plane, it will take off like a bat out of hell. i also did the ohm readings on stator, trigger, and coils. the only ones that were low were the stator. they were to be within 3600-4200ohms. mine were 3450 on both the blue and red leads, and the blue/white and red/white leads. then on the red and black stator leads, and the red/white and black stator leads i had 7500ohms. that was supposed to be 9k-14k ohms. test readings are per my mercury outboard repair manual for that motor. all measurements were made with my fluke meter. i also put in brand new plugs before i ran on the lake yesterday. motor does sneeze sometimes as well.

i was just able to go back to garage this morning and take the plugs out and all looked clean besides number 3 cylinder. the plug had a bunch of carbon build up on it with only 2 hrs of running the motor, mainly at idle. i did also add a can of seafoam to 8 gal of gas if that helps also. please help.. what could be wrong? this is all the things i checked any other ideas would be great. thank you in advance....

not sure when the carbs were last gone thru. i just bought the boat before last winter and restored the boat and now trying to get it on the water after restoring it. i did notice the last sticker on the boat was from 2008. so it must have been sitting for 4 years plus.

i did compression check. 115 across the board
i checked timing and that is on
i checked the carbs are linked up and they are on
spark is very strong on all cylinders
i have a new prime bulb and hoses
new fuel filter
fresh gas and fresh quicksilver 2 stroke oil

 

[Iceman66]

Re: 1989 v175 black max poor acceleration and idle

"when you hit the enrichment button a few times while accelerating you can get motor to get going."





Doesn`t get enough fuel I guess,plugged/dirty jets,
sounds like its time for a carb-cleaning/rebuildt and maybe a seafoam treatment.

 

[bsj21]

Re: 1989 v175 black max poor acceleration and idle

update... i took it out again last night and i had roughly 8 gal of gas left in tank and put a can of seafoam in it. after running it for a few hours again. you could tell a slight difference. you would not have to hit the enrichment button near as much to get it going. still very slow to accelerate. so i think the seafoam was doing the trick. should i concentrate it more or just run the rest of the tank like it is? or just rebuild the carbs and call it a day?

 

[1nebel0]

Re: 1989 v175 black max poor acceleration and idle

Rebuild the carbs and re-check float adjustment..I suspect your stator buy you must use a peak voltage adapter as ohms testing is not accurate...you can make or buy the adapter... I bought mine and it is a geniune Merc not that it matters...then test the stator cranking it per CDI instructions...Rebuilding the carbs is just a good idea and I do all my carb motors every couple of years given the ethanol we are stuck with....For those that don't believe how destructive it is, ask my friend who has a 15h.p. four stroke I just reubild the carb..The plastic float was warped from the Ethanol and caused serious flooding that wouldn't allow the motor to start...The marine shop told me they see this all of the time as their is no adjustment on the plastic floats but there is a spec that it must meet and his failed. Sure enough $80 carb kit and we got his motor back on the water...Who would have known other than talking to your local dealer who see's the same things over and over again...Ask them how many related fuel problems they see weekly....God help us if they go to 15% ......

 

[bsj21]

Re: 1989 v175 black max poor acceleration and idle

update 6-25-2013.

have the carbs off and rebuilding all of them. the floats were way off on all 3 carbs. i noticed on the second carb that the main jets are the same size at .064 is this correct? my mercury repair manual says that cyl3 should have .066 and cylinder 4 have .064 but mine are the same on both sides. i checked to see if when these carbs were ever gone through and somebody switched them around. but the other two carbs are good. just the middle carb is like this. i have the parts on order to build a peak voltage adapter.

i did get it running after on the hose it started up even easier than normal. i didnt even have the throttle hooked up to have the high idle when cranking and it fired right up with no problems. guess i will have to put it in water and see if that cured the issue. i hope it is not the stator. where is a good place to pick up a stator from in case it turns out to be when i test it next week? do they even sell new ones anymore?

thank you for all your help....

 

[bsj21]

Re: 1989 v175 black max poor acceleration and idle

i built my peak voltage adapter today and found these results....

i did test the adapter on a 9v battery. it read 9.2v from leads to meter. and with adapter it read 8.9v at the meter.


coil primary's -
cyl 1 - 97v@800rpm and 107v@2krpm
cyl 2 - 89v@800rpm and 105v@2krpm
cyl 3 - 94v@800rpm and 108v@2krpm
cyl 4 - 96v@800rpm and 110v@2krpm
cyl 5 - 89v@800rpm and 99v@2krpm
cyl 6 - 95v@800rpm and 104v@2krpm

switch box stop circuit - 175v @800 rpm and 205v @3500 rpm

low stator speed - 175v @800 rpm and 205v @3500 rpm

high stator speed - 60v @800 rpm and 150v @3500 rpm

switch box bias - (-5.5v) @800 rpm and (-17.5v) @2500 rpm

from the adi test results it seems that the stator is on its way out. but why is the switch box stop circuit low like this and what could this be from? also why the primary coil voltage so low? any ideas?

please help!!