1986 Johnson 90 HP

[brandon.prewitt]

I bought the boat from someone that hasn't ran it since last Summer. The oiler is removed. I'm mixing 50:1. I replaced the plugs. Replaced the fuel line and bulb. Emptied the fuel tank. Refilled it.

1st try : I ran it and it would only speed up and run if the choke was pushed in the whole time. With the choke in it ran perfect.

I put seafoam in the carbs for a couple hours added seafoam to the fuel.

2nd try : Tried it again. It only ran if choke was in but this time never over 2000 RPMs. Never got ontop of the water.

Tore down the carbs cleaned and reinstalled them.

3rd try : Tried it again and ran at idle perfect. I could speed it up to 5000RPMS in neutral. In the water would not get over 2000 RPM when in gear but does not need choke pushed in any more.

Please Help

 

[5150abf]

Re: 1986 Johnson 90 HP

Dirty carb, my carbs have 3 sets of jets, did you clean all of them, if not that is probly your problem.

You need fuel- air -fire to run, you have fire and air so it must be fuel.

If you don't have an OEM manual (not Seloc or Clymers ect) I strongly recommend you get one if you are gonna work on your motor, get one here at iboats or on Ebay.

 

[emdsapmgr]

Re: 1986 Johnson 90 HP

Running on the hose is easy. While it may sound OK, you may be dropping a cylinder. A better test is when the boat is level, sitting in the water with full backpressure. Check each plug wire for proper spark-esp after the engine has warmed up.

 

[brandon.prewitt]

Re: 1986 Johnson 90 HP

Yeah I was sure all jets were clean. I ran a small wire through all of them.

I definitely need to get the manual.

Goin to get new plugs.

I will also make sure the throttle is allowing WOT. I was thinking I may have a linkage issue.

 

[brandon.prewitt]

Re: 1986 Johnson 90 HP

No spark on the left side.

Can you test a power pack?

 

[brandon.prewitt]

Re: 1986 Johnson 90 HP

I swapped the power packs and the no spark swapped sides. Now I have to get a new one tomorrow and try it out.

 

[brandon.prewitt]

Re: 1986 Johnson 90 HP

It ran great but man it sure drinks down some fuel. Once the 6 gallons tank was empty I switched over to the 30 gallon built in. Ran fine for about 3 gallons until it started to slow down. I guess I picked up some trash. Any ideas how to clean out the tank without removing it? I siphoned 9 gallons out before I ran it. I left maybe two gallons but I couldn't get them out.