Johnson 225 VRO wont idle

[Oregondunes]

Hey guys and gals ----

I have a 1987 225 VRO. Most recently I took out a lower unit and had to have it replaced. Up until that time the motor was a lil hard to start. It's always had what I think is an over cooling issue.

Now that I replaced the lower unit, the motor is horrible to start and wont idle at all.

Ive pulled every electrical part off, cleaned every connection, tested every connection with an Ohm meter and applied dielectric grease. Ive rebulit the carbs, new plugs and wires and new therma-verns. Ive done every electrical test there is in the factory repair manual trying to find a faulty part.

During my electrical inspection I found the flywheels magnets loose. I re-ordered a complete replacement kit and installed them as directed.

I got it to finally fire tonite and once in gear it ran out just fine, but would not return to idle at all.

In the past the motor at idle it would come up to 140 degrees and idle just fine. Once underway it would cool down to water temp (actually I dont know what temp as the needle was all the way at the bottom)...then die, restart after several tries and idle back up to 140 and motor around just fine.

So I think I have two issues....the hard start/no idle issue and the over-cooling.

Any ideas ??????

 

[k4ubr]

Re: Johnson 225 VRO wont idle

i dont think you can have an over cooling problem. the lower end has nothing to do with idle, i would pressure check the VRO. if you are useing it. it should hold about 10 psi on both sides of the fuel side of the pump.

 

[jonesg]

Re: Johnson 225 VRO wont idle

Interesting problem, lets think a minute...

what is the idle speed on the hose?

I wouldn't trust the temp guage, put your hand on the cylinder head to test temp. You can feel the difference between 80F and 140f for sure.
If you find one side going cold thats the clue.

You got it to fire up, you let it warm up at idle ? ok...

Have you tried bumping the choke at idle to keep it running when coming off the throttle? Only to see if its the fuel side.

Try a timing light to see if its dropping spark to a cylinder?

Could be it warms up and drops a spark or two under load, then there not enough spark to keep running when dropping back to idle.
Thats what I would look for.

That would also explain the engine going cold under way, it drops spark and obviously will run colder. Then at idle spark returns and it warms up again.

alternatively...Look for wet plugs immediately after throttling back, cut the engine, dont let it idle, the wet plugs are the dead holes.

Also check the shift interupt switch, disconnect and run to test.

Find the cold bank and try swapping the coils to the other side, maybe the problem will follow the coils but more likely its the power pack.
You can get a peak reading meter off ebay for $60 and run powerpack tests.

If it uses 2 powerpacks swap them round, if the problem follows the PP you found it. Hope that helps.

 

[Oregondunes]

Re: Johnson 225 VRO wont idle

thanks to both of you....now I got a weekends worth of testing to do and Ill get back to you here.

Do you have a link to that tester on ebay that I can look at ?

Someone else said to buy a CD Volt meter and test the stator

 

[Oregondunes]

Re: Johnson 225 VRO wont idle

thats another issue I didnt mention. It idles and runs fine on the hose, but in the water is where the problems all surface.

 

[tashasdaddy]

Re: Johnson 225 VRO wont idle

idle speed has to be set high on muffs, then fine tuned in the water with the engine in gear. on muffs there is not any backpressure on the exhaust. suggest you do a linc n sinc also.

 

[ezeke]

Re: Johnson 225 VRO wont idle

You should start with a compression test and record the results by cylinder.

Then use an inductive timing light so that you can "see" the firing on the running engine. Inductive timing lights have fingers that wrap around trhe spark plug wire so that you do not need to remove anything.

Check to be sure that the timing advance is working when starting your motor - it's mechanical, so you have to watch the linkage at the engine.

The loopers hate running cold, so make sure that the thermostats are functioning properly.

 

[jonesg]

Re: Johnson 225 VRO wont idle

thats another issue I didnt mention. It idles and runs fine on the hose, but in the water is where the problems all surface.

but in the water is where the load is, no load... no problem.!
Thats great if you want to do all your boating in the driveway.

Try all the troubleshooting proceedures before delving deeper buying special test equipment, I think you'll find the problem in 30 minutes.

Do as Tash recommends, check your linc and sync settings.

Its gonna be something simple.

 

[ezeke]

Re: Johnson 225 VRO wont idle

It's Linkage and Synchronization.

 

[Oregondunes]

Re: Johnson 225 VRO wont idle

thanks everyone. I will test it all this weekend and report my findings here.

I Wish some (or all for that matter) of you were closer to me. Your experience and helpfulness is truly appreciated.

 

[Oregondunes]

Re: Johnson 225 VRO wont idle

the primer bulb stays fairly hard once primed.

The plugs last night were BLACK and wet....obviously cause I tried to start it over and over and over.

Im leaning towards an ignition problem (or lack there of) below say 1500 rpms. It runs like a bat out of hell once you get it off idle.

 

[another todd]

Re: Johnson 225 VRO wont idle

Sounds similar to my 130 HP motor. Runs 140 at idle and cools off to just above water temp under way. I researching that, almost everybody has said that it is normal. The thermostats push off under pressure allowing full bypass of water, hence the "over cooling". Although my idle isn't as bad as you describe, it isn't great. I have found the recirc. system may be at fault. In testing the check valves, 2 of the 5 were suspect testing both good and bad at times. I have ordered 5 new check valves and am awaiting arrival. I hope this clears up my problem, and may be something you want to look at as well. I was fouling plugs every trip, even with synthetic oil, especially in the lowest cylinder in the engine, which pointed to the recirc. system.

 

[Oregondunes]

Re: Johnson 225 VRO wont idle

Sounds similar to my 130 HP motor. Runs 140 at idle and cools off to just above water temp under way. I researching that, almost everybody has said that it is normal. The thermostats push off under pressure allowing full bypass of water, hence the "over cooling". Although my idle isn't as bad as you describe, it isn't great. I have found the recirc. system may be at fault. In testing the check valves, 2 of the 5 were suspect testing both good and bad at times. I have ordered 5 new check valves and am awaiting arrival. I hope this clears up my problem, and may be something you want to look at as well. I was fouling plugs every trip, even with synthetic oil, especially in the lowest cylinder in the engine, which pointed to the recirc. system.

Todd

Thanks for the heads up...keep me posted please.

 

[ezeke]

Re: Johnson 225 VRO wont idle

If you have not done so, de-carb your engine before you put your new recirculation check valves in or they will just get clogged up as well.

 

[Oregondunes]

Re: Johnson 225 VRO wont idle

OK.........so it's been a while since I was perplexed with my issues. I gave up and took it to the stealership. Actually, they have turned out to be pretty great guys and Im very happy with the results.

Here is what they found.

1. Carbs jetted (both air and main) -4 sizes for sea-level (very lean)
2. Enrichment valve set from "auto" to manual and in full rich mode.
3. Enrichment valve had crack cover. First spraying fuel at start and low idle, then sucking air at WOT (causing it to lean out even more).
4. Timing was way off. was only getting 11 degrees advance at WOT.

All of these issues were "reset" to factory specs and now she runs like a champ. Im looking forward to installing my new high speed jack plate, nose cone and cleaver style prop. My goal has been to exceed 70 mph without a headwind. I hope to reach that before the "boating season" is over this year.

 

[Oregondunes]

Re: Johnson 225 VRO wont idle

oh and now that the engine is running correctly, my temps are a lil higher. Still not holding at 140, but were gonna try some new thermo's and see what happens.