1980 Johnson 120 VRO hard to start cold.

[kbmsound]

I just bought a 20' wellcraft with 1980 (i assume) Johnson 120VRO, will post serial later. It looks to have many new parts (starter, coils, and the heads look to be in pretty good shape)
Tried in the river before buying, ran great at about 4k rpm for about 5 minutes. Not a peep. Every thing works, except no temp gauge. Took it to the bay hours later, ran it at about 4200 rpm. got a buzzer alarm after 2-3 mins of run time. Then it would not start. Started again later after 20-30 mins. First i thought fuel delivery, but squeeze pump was fine and got rigid after a few pumps with a tank full of gas. I am thinking over heating? Then got home about 3 hours later, tried to start on muffs, but it took for ever to fire up (like 4 or 5 tries of 5-8 seconds each) Any thoughts? I have heard that these Johnson can be hard to fire up when cold. Is there a specific sequence to follow when starting them? I read here that lifting the choke lever is not good when cold.
Thanks,
Les.

 

[racerone]

Nope,---You have to lift the lever when motor is cold.----------You have to push the key in during cranking for primer to work.---No such thing as a motor in good condition that is " hard to start " in my opinion.

 

[jakedaawg]

Post model # not serial number. It will be something like J120 and some letters. If it has a VRO it is later than an 80. Model # can be found on the engine clamp or on a silver welch plug on top of the block.

There is a good how to start section in the sticky file at top of page. Read it, easier than typing it out again.

You need to diagnose the alarm. Was it a solid horn, a rapid beeping, or a beep every few seconds?

Do to it being a new to you motor you should compression check 1st, and then replace water pump impeller.

 

[kbmsound]

Post model # not serial number. It will be something like J120 and some letters. If it has a VRO it is later than an 80. Model # can be found on the engine clamp or on a silver welch plug on top of the block.

There is a good how to start section in the sticky file at top of page. Read it, easier than typing it out again.

You need to diagnose the alarm. Was it a solid horn, a rapid beeping, or a beep every few seconds?

Do to it being a new to you motor you should compression check 1st, and then replace water pump impeller.

Well, I will try to look for serial later.(at work now). The cowling looks original and says 120 VRO. Will also post pics later. As for the alarm, it came from the control box, and it was a solid buzzer type sound. I will replace the impeller, and i will also install a temp sender and gauge. I will have to get me a compression tester to check that. What bums me out is that it ran fine one time, and not the other. Somethings is not working like it should.

 

[jakedaawg]

a solid horn is an overheat.

 

[kbmsound]

a solid horn is an overheat.

So, possible cause could be bad impeller? I kept an eye on it and it seemed to **** really strong. The previous owner said he adds oil to fuel tank, which leads me to believe its not a vro engine, rather a normal premix one, with a different cowling. Maybe its not enough oil in the fuel?

 

[jakedaawg]

Could be several issues. Start with the compression test. I suggest you run engine only on 50:1 pre-mix until everything is sorted out. Bad impellar/water pump, bad fuel oil mixture, bad t-stats and such all possible causes. Get an actual J/E shop manual if your gonna do the work yourself.

 

[kbmsound]

Could be several issues. Start with the compression test. I suggest you run engine only on 50:1 pre-mix until everything is sorted out. Bad impellar/water pump, bad fuel oil mixture, bad t-stats and such all possible causes. Get an actual J/E shop manual if your gonna do the work yourself.

Tank has about 3/4 gas left in it. I don't know if previous owner used correct ratio of oil. Would I be wrong to add a bit more oil to be on the safe side, while I replace thermostats and impeller? I should mention the boat is a Wellcraft V20 '79. I believe they came with a 60 gal fuel cell...right?

 

[jakedaawg]

For the time being, borrow a portable tank and fuel hose. Fill it with pre mix. Run on that for now. Buy a cheap one if you have too, if your gonna do your own stuff it will be a necessary tool to have.

 

[kbmsound]

So to close the thread and give you guys and update. 1. I found the Model Num as J120TLCUR which makes it a 1987 Johnson 120 VRO, and that makes me happy because I thought the motor was much older. The previous owner did not know the exact year. 2. It is a VRO but it has been taken off and replaced with a regular fuel pump. 3. I put a bit more oil in the tank, and installed a new gas bulb. Took to the water again, this time only with my wife ( Failed to mention on OP that when the incident happened I had 10 people in the boat, a 20' Wellcraft V20 Step Lift) Ran it for about 45 mins at 2000-4000 rpms and it ran flawless. It started every time, never stalled, and no alarms. So I am attributing the overheat alarm to the weight on the boat, and running it at 4k rpms

 

[jimmbo]

What was your wide open throttle rpm with just the wife?

 

[kbmsound]

What was your wide open throttle rpm with just the wife?

I didn't take it to WOT.. I went up to 4k rpm with just the wife on board.