91 Johnson 175 gt

[wcyoung101]

Hey I have a 91 Johnson 175 I got on my boat currently. As long as I have had the motor Its always had issues starting and idling. Here recently it's got to where the motor will just cut off got about 75% throttle on plane. It's got new spark plugs in it but I haven't done anything else to it. I also check the compression on it warm and all cylinders are just under or at 90 psi. Anyone got an recommendations as to why it idles rough and is hard to start and also why it shuts off like it does?

 

[racerone]

Needs a rebuild ?

 

[brodmann]

If it's always been hard to start and has always idled poorly, you have probably always run it lean at low speeds. The time to fix this probem was years ago.

 

[wcyoung101]

If it's always been hard to start and has always idled poorly, you have probably always run it lean at low speeds. The time to fix this probem was years ago.

I haven't owned the boat more than 6 months and it's only been on the water a handful of times

 

[racerone]

What is your starting procedure ?

 

[wcyoung101]

What is your starting procedure ?

Usually I prime the bulb and I choke it to start but I usually have to press the hot foot about half way to even get it to attempt to start

 

[racerone]

Do you push the key in and hold it in while cranking it over?

 

[wcyoung101]

Yes sir

 

[racerone]

I would say 90 PSI compression is too low.----Needs to be rebuilt I think.

 

[wcyoung101]

Okay what all would that entail doing? Pulling the pistons and reboring?

 

[racerone]

Remove bypass cover for #6 and post pictures of piston and rings.

 

[wcyoung101]

Remove bypass cover for #6 and post pictures of piston and rings.

That would be the other bank correct?

 

[racerone]

?---#6 is the lowest cylinder on your motor.