75 165HP iL 6 (gm 250)

[Turfboy]

Hello all, recently came into owner ship of a 165hp merc with a in-line 6. Water was in the oil, took it all apart replaced head gasket, changed oil, fired it up. Ran for 20min reved up to 2,000rpm and sounded great, changed oil and filter to get rest of the milky oil out. Fresh oil and filter, fired it up idles fine, but will not rev up past 600rpm. Oil looked clean so we solved that issue. But can not figure out why it won’t idle up. New fuel filter, new fuel pump, fresh gas. Like i said before last oil change it reved up just fine. But now it won’t. Any help please and thank you.

 

[alldodge]

Howdy
The carb throttle opens up but it stays at 600 rpm?

 

[Turfboy]

Howdy
The carb throttle opens up but it stays at 600 rpm?

Yes the carb throttle plate will open, but when it does it starts to hesitate, skip, and then die. I can back the throttle back off right away and it’ll pick back up and idle just fine.

 

[alldodge]

Sounds like a carb issue.

Has the fuel filter been changed? If not dump the contents of the filter into a clear container to see if there is nothing but clean gas

When the throttle is opened does fuel squirt down the throat of the carb?

 

[Scott Danforth]

I agree, go to the carb, sounds like the primary jets are plugged

 

[Turfboy]

The filter looks to be newer, but is easily accessible so will take it off and drain, had to take the fuel line off when taking the head off, the fuel in that line was a little off color. I could not see fuel spraying in the throat.

 

[alldodge]

Fuel being discolored would mean its old and bad. Gas should be clear as water

Not seeing fuel when throttle is pumped then your not getting gas to the carb. This means bad fuel pump or a restriction

 

[Turfboy]

Fuel being discolored would mean its old and bad. Gas should be clear as water

Not seeing fuel when throttle is pumped then your not getting gas to the carb. This means bad fuel pump or a restriction

Clear as water huh? Well it wasn’t that. Will take filter apart and carb and clean it all and see what happens, thank you all for the replies.