1990 Johnson 70hp VRO - Starting Issue

[tmljunkmail]

The members of this site have always come through for me in the past. Hopefully they will again.

Have a 1990 Johnson 70 HP VRO -- VJ70TLESB

Just bought it from a friend.

Have used it 3 times since purchase with no problems at all. Started up just great and ran at full throttle for extended periods at high speed.

Had it out again yesterday. Unit started and ran great several times that day.

Near the end of the day it simply would not start. It tries to turn over but won't catch. The water pump runs too, but it just cranks and cranks.

Thought it might be floodded or perhaps out of gas (even though gauge read full). Tried both with no luck.

Eventually pulled it out of the water and replaced the plugs which were pretty bad. Tried again with no luck.

Took off carb/air cover (if that's what you call it) and took a look at carbs.

It should be noted that this engine is CLEAN. I mean REAL clean like it is new (part of the reason I bought it).

Anyway....carbs seemed to be soaked. I blew on them and gas came out.

Tried tapping on each carb to drop the float....with no apparant success.

Subsequent attempts at restart are all the same......crank but won't turn over.

I'm mech inclined but don't have a lot of experience with engines. I hope I've given enough info here to give someone enough idea to point me in the right direction.

Thank you in advance for any help you can provide.

 

[Windykid]

Re: 1990 Johnson 70hp VRO - Starting Issue

Are you getting spark?

 

[johnson1989]

Re: 1990 Johnson 70hp VRO - Starting Issue

You will need to check spark and compression and report back. You may have lost a power pack or something similar. One you report back Joe or some of the other high end users will be able to help

 

[ezeke]

Re: 1990 Johnson 70hp VRO - Starting Issue

Check the lanyard on the emergency kill switch while you are at it. Then disconnect the black and yellow kill wire at the powerpack. You may be shorting out. Be sure the throttle arm is in neutral - shake it around a little.

 

[tmljunkmail]

Re: 1990 Johnson 70hp VRO - Starting Issue

Not sure about spark.

Obviously I was getting spark earlier in the day when it worked.

I will check it when I get home.

(ok.....try not to laugh too much at this next one............)

I assume I can remove the plug and look at it out of the chamber while attempting to start?

As for compression....I need a special tool for that, correct?

Sorry about the dumb questions....like I said....I am actually very mechanically inclined, but I just don't have much experience with engines. (Brake jobs, oil changes, etc....yes.......more in depth.....not so much).

As for the lanyard.....I did check that. It seems to be working properly....however...I will try your bypass just to make sure.

Thanks again for all the insight.....it really is appreciated.

 

[Windykid]

Re: 1990 Johnson 70hp VRO - Starting Issue

Yes you can observe spark with the spark plug out. It must be grounded.

And yes you need a compression cage sold at sears or any parts store.

Remove all spark plugs open butterfly,s . Install gage i a cylinder, crank engine 4-6 revolutions. Record reading and move on the next. No more than a 10-15% between all cylinders. Good luck

 

[tmljunkmail]

Re: 1990 Johnson 70hp VRO - Starting Issue

Ok......an update.....

Got home tonight and double-checked some things.

Don't think it is the emergency cutout switch.

In any event.....put the muffs on and it FINALLY turned over.

Dropped it in the water and it ran like a top. Started it....stopped it....no apparent problems.

Sooooooo?

I'm not sure what I learned......

I suppose its possible it was just REALLY REALLY flooded (I let it sit and air out for HOURS yesterday with no luck).

The only other explaination I can think of is that the float in the carb was stuck??

Anyone have any ideas what was wrong or what I should do at this point?

It appears the problem is resolved (at least temporarily), but now I am a little leary about it happening again while I am in the middle of the lake.

Ideas anyone?

 

[Kevin W]

Re: 1990 Johnson 70hp VRO - Starting Issue

A small backup kicker motor would be wise.
It sounds electrical.
keep an eye on the emergency switch I have a 85 70hp johnson and the switch crapped out and made it dead as a doornail.
it would crank but without even a sputter.

another possibility is the keyswitch.

It is possible that you could have seriously flooded it but it usually will sputter.
I doubt it was a stuck float because you have 3 carbs on the engine and it is unlikely to have all 3 stuck at once and have it recover and run.
If one was stuck the other 2 cylinders would still fire.
It is possible it is a powerpack.
it is also possible the electric choke was stuck on.
.02$

 

[rickdb1boat]

Re: 1990 Johnson 70hp VRO - Starting Issue

Start it on the muffs and point a hair dryer set on high heat real close at the powerpack. See if it dies...

 

[tmljunkmail]

Re: 1990 Johnson 70hp VRO - Starting Issue

Thanks all for the help and input.

I've been doing some reading and am wondering if you think it would be a good idea to do a seafoam treatment to clean things out.

Any thoughts?