1991 Johnson 175 Motor Problems

[markdenisr]

I have a 1991 Johnson 175 HP Serial# J175GLEIS....19ft. Blazer bass boat. I have a few problems that I could use some help on.

First, when in idle many times I have to push the choke in to keep it from dying. It does not matter if the motor is cold or not.

Second, The last time out when I tried to put the boat on plane, it would get right at 2300 RPM's and just before it planed out it would start missing real bad and fall flat on its face. This happened several times and it is always at 2300 RPM's. It would not stop running..it would just return to a smooth idle. It would do this if I idled around a bit before I decided to get on plane. If I let it set a while, it would take off like normal. I have a water pressure gauge and it reads about 5lbs in idle and around 20-25lbs on plain...all seems normal there.

Also, the VRO is unhooked and I mix my fuel. I have not made any mistakes and it is mixed properly, but every once in a while I will get some short warning horn sounds only on idle and never running WOP.

Anyone have any ideas? I could take it to my local boat mechanic but I have an idea they are going to want to start replacing things without knowing for sure what the problems may be. I think it could get real costly if I go this route.

Thanks in advance, Mark

 

[jonesg]

Re: 1991 Johnson 175 Motor Problems

bump...

did you disconnect the elec plug to the oil pump?
are you sure its not overheatin?

I don't know much about outboards but the fact you have to choke it to keep running says fuel, not ignition to me.

If its the elec choke like on mine, that bypasses the carbs, I would look towards carb restriction and/or the feed line to the carb for air leaks.

 

[markdenisr]

Re: 1991 Johnson 175 Motor Problems

Yes the oil tank has been completely removed from the boat and the 4-wire plug along with 2 more wires (black & tan) has been disconnected. I have checked and tightened all the fuel lines and all seems to be OK. The primer bulb does not loose its prime at any time during motor operation. Is it possible that the VRO on the motor could have an air leak around the gasket? Is there a plate I can buy and install so I can remove the VRO completely?

No I am not sure it is not overheating because the water pump seems to be pumping normally at least by the pressure gauge and it does have a steady stream all the time. Could it still be overheating? I bought the boat over 2 years ago and have never replaced the water pump because it always showed a good stream of water.

Sometimes the horn will beep a few times just a few seconds after I start it...no way could it be hot in that short of time.

Is there someway or some product I can flush the carbs and maybe help the problem before I have them rebuit?

Thanks, Mark

 

[clanton]

Re: 1991 Johnson 175 Motor Problems

The horn is suppose to beep when you turn key to on, SELF TEST, If beeps more then once doing SELF TEST the horn is bad.

You disconnected VRO sensor wires and oil tank sensor wires, you have 2 sensors left, over heat, fuel restriction both make a continious alarm, when set. The running problem is caused by over heat setting the S.L.O.W. which reduces the rpms to 2500, the power pack is bad or both. Water pressure also looks a little wimpy.

 

[markdenisr]

Re: 1991 Johnson 175 Motor Problems

Thanks for your reply. I will put a new water pump on this week and report back with the results.

THE SERIAL# of the motor is J175GLEIS and it is a 1991 Johnson 175 H.P. What is the best brand and possible part number and place to order it, and do I need to just replace the impeller or replace all the parts of the water pump?

I forgot to mention on my original post and this post that my motor has the bullet point lower unit with low water pickup.
Mark

 

[clanton]

Re: 1991 Johnson 175 Motor Problems

I would replace the complete waterpump assy with an OEM kit matched to the modle number of the engine.

 

[clanton]

Re: 1991 Johnson 175 Motor Problems

Waterpump kit pn 0395864

 

[jonesg]

Re: 1991 Johnson 175 Motor Problems

you might find this usefull.

www.themarinedoctor.com/waterpump.wmv

and a temp guage?

 

[markdenisr]

Re: 1991 Johnson 175 Motor Problems

Thanks for all your help. It appears I may have a heat issue when during long idles from the marina out to the no wake zone. I will change the entire water pump system.

Now I do have another question about the carbs. Is there anything way to flush the carbs or put in the fuel before I have the carbs rebuilt that might help clean them?
Thanks, Mark

 

[markdenisr]

Re: 1991 Johnson 175 Motor Problems

I ended up taking it to the local boat mechanic and had him install a new complete pump and thermostats. Everything seems to be working fine now.
Thanks for the help.
Mark