Johnson 115 '84 V4 Losing power (and dying) under load

[Fastworker]

Bought a boat package with this engine. Ran for a few runs and seemed to be running OK - The motor got the boat (like a Boston Whaler 18') up on a plane and up to >25kts. It was a bit difficult to start at times. Boat came ashore from a mooring and some water washed over the enginer but didn't swamp. Started and ran reasonably OK, but wouldn't restart. As I wasn't aware of the history or condition I sent it to a mechanic for some checks. So far, between us we has done the following:
- Cleaned tank and new fuel and 50:1 mix.
- Stripped and rebuilt carbs with new gaskets. Did not strip Reed valves.
- New Fuel lines
- Using pre-mixed fuel and isolated two-stroke feed
- Compression is between 95 and 108lbs
- Spark in all cylinders.

Right now I have it starting OK in the water - Idles OK, but sounds a little uneven. Motor rocks a little back and forth a little. Is this unevenness typical for a V-engine?
Problem is when I engage reverse it just cuts out. Similar with forward unless I up the rev with the idle lever.
One other point, there is a trickle of oil running down the outside of the shaft - Any thoughts on this?
Any suggestions where I go next?
Wondering if there is something I should check about the detailed spark timing and advance etc.
Anything else. I don't know the service history of the engine except that it was running reasonably OK recently and that the ignition coils on one side had been changed last year.
I need to get a workshop Manual ( Any suggestions which I should get? - Any available by e-book?)
I've already missed most of the summer season, so really keen to get on the water to get things right for the start of next year!
Any help greatly appreciated!

 

[metcalfej]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

It looks as though you realy have gone to town on this however, just to make sure that you didn't forget obvious things like tuning the engine under load, because it sounds as if the mixture getting through isn't right and I wonder whether it was tune in neutral hence is running too weak a mixture

Hope you get back on the water soon

 

[Fastworker]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

Thanks for the reply - By tuning, what had you in mind? I haven;t made any specific adjustments, do you mean idle speed adjustment of fuel mixture?

 

[KYHunter2]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

The best manual to get is an oem, for your specific motor and year.

The compression doesn't sound too bad.

Though seems a might low.

Do a decarb , and retest. They need to be within 10 - 15 percent of each other.

When you did the spark test , was the spark bright blue and able to jump a 7/16 " gap ?

There's not alot to set on the carbs, really just a link and sync.

When the guy rebuilt them did he thoroughly clean them and blow out with compressed air ?

Also besides just the gaskets.

Were the needles , seats and floats replaced ?

As a matter of fact if they were rebuilt , then the link and sync. had to be done .

If it wasn't , then that could be alot, or all of the problem.

Also , since you dont know the history of the motor.

A new waterpump is a must.


This will give you a few things to check.

If you google the manual for your motor , you should find it.

There are alot of manuals being offered on e-bay as well.

KYHunter

 

[Fastworker]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

Thanks for the help.

the guy blew out all jets with compressed air. Not sure that he replaced the float, seats and needle. I can check. I'll repeat the spark check for the 7/16 jump.

On the link and synch adjustment - Am I right to assume that this just adjusts the idle level and the balance between the carbs? is the adjustment done - is it just balanced based on listening for the most even idle? The guy mentioned that it needed to be done, but we had wiped the battery at that time, so he needs to come back to complete that.

Time to get the manual I think. Thanks again!

The new water-pump: is this just sensible to avoid a pump failure blowing the engine or do you think it could be related to the problem?

 

[KYHunter2]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

If the link and sync. is done correctly .

As well as the WOT timing , under a load.

The low speed idle should take care of itself.

The timing has to be in sync. with throttle , as well as carbs in sync. with each other.

The timing is advanced along with the throttle.

I doubt the water pump is causing your running problems.

But, you do need to verify that the over heat switches and horn are working.

If you dont have one, a water pressure guage is invaluable, to monitor water pump condition and coolant flow.

The reason I said to rebuild the pump.

Is that they need to be rebuilt about every 2 years.

Cheap insurance, to prevent overheating.

Another thing to check, whether it has anything to do with your problem or not.

Is clean all the grounds , engine , coils etc.

And the pins on the amphenol plugs.

I just use some emery cloth ,and a small screw driver to wrap it around, and shine them up.

And yes , the manual is the only way to go.

We can try to help as much as possible.

But its much easier, when you have a manual .

So, you'll understand more of what were referring to.

As well as the procedures, that are too long and varied to do without it.

KYHunter

.

 

[emdsapmgr]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

You could be dropping a cylinder. Run the engine under load, then put a timing light on each plug wire. Each should have a flash, on a constant, regular basis. Look for misfires every 4th or 5th flash. The engine will run on 3 cylinders, though it will vibrate.

 

[tashasdaddy]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

the best manual is the OEM manual #394607, at Kencooke.com it is $120.00 . watch ebay and try to find one.

 

[Fastworker]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

the best manual is the OEM manual #394607, at Kencooke.com it is $120.00 . watch ebay and try to find one.

Kencooke.com??

I tried that site and it's a company selling Pergolas!??

Appreciate the help...


Colum

 

[ezeke]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

Mr. Cook does not have an 'e' in his last name.

"http://www.kencook.com/evinrudejohnsonmanuals/"

Also:

"http://marineengine.com/mfr/johnson_evinrude_outboard.html"

"http://www.maxrules.com/fixbooks.html"

Copy to your browser without the quotation marks, please.

 

[xtraham]

Re: Johnson 115 '84 V4 Losing power (and dying) under load

http://www.kencook.com/evinrudejohnsonmanuals/index.cfm?fuseaction=home.main