1981 Merc 175 power issues.

jaywalla

Cadet
Joined
Sep 4, 2007
Messages
19
So here is my problem. My motor seems to be picky about when it will give you full power. If i put the motor in WOT it seems to chug along for a while then without warning the motor pick up real quick. If i stay in the higher rpms after i get it going good i can keep all the power, but if i take it back down and try to go again it is the same thing. No power for a long while fallowed by allot of power all at once.
Can anyone tell me what i should check to resolve this issue?
 

jaywalla

Cadet
Joined
Sep 4, 2007
Messages
19
Re: 1981 Merc 175 power issues.

The motor is also verry hard to get started. I have been using starter fluid but have lerned that that is a big no no. It sounds like i should be checking the fual lines, Bulb, Enricher (Wich i thought was a choke) and cleaning the carborator.
Does anyone have some input that might help?
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 1981 Merc 175 power issues.

Fuel delivery at slow speeds (fuel pump)
Carb low speed circuits mis-adjusted or clogged
reeds. Usually shows up as a significant misfire at idle.
manifold air leak
stator or switchbox (missing on 1 to 3 slow speeds)

just a few possibilities
John
 

jaywalla

Cadet
Joined
Sep 4, 2007
Messages
19
Re: 1981 Merc 175 power issues.

Thanks,
I just replaced the gasket for the manafold few weeks ago and did not notice any leaks after doing so, I also replaced all the spark plugs and made sure they all had a strong spark.
So i guess that leaves the card and fual system. It seems that the linkage for the enricher broke some time over the last week. I will have to fix that also. I am going to pull the carb and check everythign there tonight.
 

jaywalla

Cadet
Joined
Sep 4, 2007
Messages
19
Re: 1981 Merc 175 power issues.

Upon my initial investigation i found that one of the pressurized gas lines running to the bottom 1/3 on the carb had a significant leak. I changed it, primed the motor and it started right up from cold.
I noticed also that when i prime the motor to start that it squirts gas out of the front of the carb. Is that normal?
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 1981 Merc 175 power issues.

Upon my initial investigation i found that one of the pressurized gas lines running to the bottom 1/3 on the carb had a significant leak. I changed it, primed the motor and it started right up from cold.
I noticed also that when i prime the motor to start that it squirts gas out of the front of the carb. Is that normal?

No, it's not normal. Either the float is sunk, or the needle valve is defective or has a bit if debris in it, holding it open.

Some of the early V6's had foam floats in them, which sunk immediately when gasohol came on the scene. The new solid plastic ones are so reliable, nobody, including aftermarket vendors, makes them. (no market) If you need them, buy a used set of later carbs cheep off'n eBay to get the floats.

Glad you didn't do this with the broken gas line.

John
 

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