93 johnson 115

[grassmole]

I have a 1993 115 Johnson on a 94 Xpress aluminum bass boat. The motor had a slightly warped cylinder and i have had it fixed. I'm in the process of getting a new Tach because the old one is shot.

The problem i am having right now is the motor doesn't get the boat on the right plan when i am wide open. also it burns fuel extremely fast. i went through 17 gallons of gas in 25 - 30 minutes of riding. please any help would be greatly appreciated.

Motor has good compression, new plugs and everything else seems to be ok. The prop that is on it is a Viper 13 7/8 X 19.

 

[Walker]

Re: 93 johnson 115

Spark test?? Do you have fire to all 4 cylinders?

 

[grassmole]

Re: 93 johnson 115

i will make sure of that tonight when i get home. I believe i do but i don't want to mislead you, and move on to other troubleshooting.

 

[grassmole]

Re: 93 johnson 115

sorry it has taken so long to get back with you guys, but yes i am getting spark from all 4 plugs, i also put in new plugs. I looked up the model through Google and found the correct plugs i needed to get and went and picked them up from my local automotive parts store.

 

[tashasdaddy]

Re: 93 johnson 115

you are pouring fuel out somewhere. it should burn not more than 12 gallons an hour.

 

[grassmole]

Re: 93 johnson 115

i have looked inside the boat thinking there was a leak in the tank but i find no fuel anywheres in the hull of the boat. If it is leaking from in the motor i don't see it there either. any suggestions on where to start looking?

 

[hoeser]

Re: 93 johnson 115

Follow your nose... Really inspect your tank and ensure its not leaking into the hull. Do you have a metal tank? If so, it may have rusted through in an area you can't see.

Inspect fuel line to the engine, you may be losing it in the transom area and dumping it into the water under draw/pressure. There is no way that engine will burn 17 gallons of fuel in 25 minutes without a leak somewhere... unless perhaps there is a seriously incorrect assembly in the carburetors. Even 12 gallons an hour seems excessive to me.

 

[grassmole]

Re: 93 johnson 115

The boat is an aluminum xpress bass boat, the tank is a plastic rectangle shaped tank. I have checked the hull of the boat on several occasions while running, then once the boat was on the trailer i checked it again also. i pulled the plug and only about a half gallon of water comes out of the hull. I will inspect the line going to the motor, i may just go purchase a new line just to get that detail out of the way.

 

[reeldutch]

Re: 93 johnson 115

check the fuel pump(vro) for leaking gas into the pulse line .

this would explain not reaching wot and exessive rich running motor and abnormal fuel consumption.

 

[grassmole]

Re: 93 johnson 115

i have not found the leak in the gas line and also i am unsure where to look. I did replace the line from the tank to the motor. I found that the old hose runs through a fuel/water seperator. I have taken the seperator out of the loop for now. if you have any information on where the VRO is located, that would be greatly appreciated.

I have also replaced the Tach and while on muffs in the driveway, the motor is ideling at 1400-1500 and sometimes the tach will drop to 0 for about half a second.

 

[grassmole]

Re: 93 johnson 115

**bump**

 

[Molaker]

Re: 93 johnson 115

I'm not sure about that motor, but I assume is has float bowls on the carbs. Your problem sounds like it could be a needle valve stuck open having the effect of running with the choke on. This could account for the low power and the high fuel usage.

 

[grassmole]

Re: 93 johnson 115

the carbs have recently been rebuilt by a local boat shop. would that needle valve be included in the rebuild?

 

[Molaker]

Re: 93 johnson 115

It most likely was included in the rebuild, but that doesn't forego the possibility of there being a problem with one. The rebuilder may have messed up or it could be caused by crud in the gas or any number of possibilities. Of course, this is assuming a needle valve is the problem.

 

[grassmole]

Re: 93 johnson 115

**Update**

I found where the gas was leaking from, there was a hose that was coming off of the back of the gas tank, this hose use to be hooked up to the external oil pump. There was a fitting in the end of this hose (which i had overlooked like an idiot), the fitting was a splice instaed of a plug. The gas was running right out of this fitting. Also my auto bilge pump was pumping the gas right out and i was unaware of it.

Also i cut the 2 trim tabs off of the back of the boat (there were 2 trim tabs welded on the back of the boat). Now the boat gets up a flys. It trims right, it runs right, its no longer a wet ride.

I am still having a problem starting the boat. It took 15 minutes for the boat to finally start. It would turn over but would never catch on and stay running. Finally after some finess with the throttle cable and some patience, i finally got it started. After that it would start everytime i would turn the key, but the idle was real low on start, but after i run the boat when i move the throttle to the idle position it was idling high. I do not remember the exact RPM's i will try to gather that info this weekend.

Is there a specific starting procedure for an older johnson motor?

Thanks everyone for trying to help, and thanks for future advice.