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1974 9.5 johnson. slow/low power

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phoen1x

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Ok.

Got the boat out today (75 degrees!) Just the wife and myself. I've run this motor in a trashcan to see if it would run (it does.) but this is the first time I've run it under a load (people and moving a boat) The bot it is on is a 13 10" vee hull jon boat. With the wife and I and running it full throttle it was only 7mph via gps) Also when I turned around headed into the wind (slight breeze and wake of another boat it started shuddering and conked out. It restarted easy enough but it never seemed to have power.

I expected a bit better power and speed.
 
ok. I have not had the chance to run the motor yet (too late now I don't want to disturb the neighbors) but I did pull the plugs and look at them. The white crown on the electrode looks ok. (nice light brown even coating.) It looks like both plugs have fired, and they are both new. Both plugs did have a black oily sheen in them and looked to be wet. The top plug especially.

I wonder if I had the choke set poorly or something. I am sure I have the right amount of oil in the tank.

that what I have so far.
 
Gas is less than a month old. I have additives given to me by the marine shop to help combat ethanol, as well as stabil etc. I'll try the thing you suggested tomorrow during the day. I did see one reference that stated this condition oily can be because of "running in" I assume a break in period.

http://www.triumphspitfire.nl/plugs.html

other sort od said the same thing. The motor is rebulit and looks new. so maybe...hope springs eternal. I ran it for maybe 30-40 minutes on the lake.

as an aside I have a friend who has the same set up A 9.9 Yamaha and he claims by himself he can get 21 MPH now maybe these engines are so different that this 9.5 will never be able to do that. The reference you guys gave me from a different thread about the tilt pinion said the motors are also low compression like 60 instead of 100 for each cylinder. If that means anything.

http://www.leeroysramblings.com/OMC_9.5.htm

I may just run it by a shop.
 
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Spark must be able to jump a gap of 1/4" with ease !----So do that test and report the results.----An answer like " good spark " does not help you in any way !
 
ok. So I ran the motor.

some observations: to start the the tiller handle cannot be in the "start" position it has to be in a position further left (as you face the engine) towards the Faster setting. If at any time I move to towrds start or rest on start it starts to choke up and die. I don't know it its helpful but I figured I mention it So if the tiller is on "start" I cannot start the engine or idle near there.

Sparkplugs. Ran the motor took out my trusty rubber handles channel locks pulled the wire off of the (top spark plug) OUCH! I guess they are not insulated and after all. Motor died immediately. ETA: I do believe that the spark jumped far enough since I am pretty sure I had the waire off when I got shocked.

Went inside got a rubber mat from the bath tub (wet ground) Got a different pair of channel lock with a rubber tip and a rubber handle
replaced the wire. Fired up the motor wiggled off the wire from other (bottom plug )and motor still runs. Also no shock.

Model and serial numbers (from the stern bracket plate I could not find any on the engine block, at least not yet.)

from the numbers I can read

Model number: 9222M

Serial Number: J018002

The gentleman who sold the motor to me called it a 1974 9.5 and the motor on leroy's rambling (http://www.leeroysramblings.com/OMC_9.5.htm is an exact match for this one. So maybe the guy who sold it to me has the year wrong, or Johnson switched in the middle of that year but whatever it definitely a 9.5 hp engine.

So now I am going to switch the plugs. I hope I don't get shocked again!
 
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ok switched the plugs

Pulled the bottom one first. Engine almost stalled but kept running. I moved the tiller a bit to give it more gas. ran ok. (No shock!)
replaced the wire. started the engine Pulled the top wire (no shock hooray!) Engine died immediately.

So this means? It runs on one cylinder. That why it does great without a load but does not with a load.


Thanks for your help guys really.
 
Ok tested the compression both cylinders come at 60 whix=ch according the leroy says is ok. I could not get either cylinder to spark with a spark tester but I know there is spark there since I shocked the crap out of myself today on the top spark plug. The spark tester did not fit very snug into the spark plug wire so....
 
You need to accept the fact that 73 was the last production year for the 9.5 model.---------Yes the motor is only running on one cylinder.-----Pull the flywheel and inspect the dual ignition you will find there.---One ignition system for each cylinder !!!
 
9222m was an Evinrude model designation ! ---You say your motor looks like one on the Leroy site,-----If it is a Johnson and it is painted all white it is a 64 , 65 or 66 model.---------Post a picture if you like.
 
Thanks guys I did see that. thanks for your help. I was hoping to just replace maybe condensers and then points but as per your advice it probably make more sense to just replace those as well, just to save time if nothing else. because chance are good it could be both!

Thanks for you help guys.
 
Those coils if original are likely cracked.------Inspection will tell you.---Make careful notes on how the coils are positioned if you need to replace them.---These coils often burn through on the bottom and short to the magplate.----Pull the flywheel and post a picture of the coils.
 
Is this difficult work to do. I am a novice at this, and the last thing I want to do is screw this up so it does not run at all!
 
You need to use a puller with 3 bolts to get the flywheel off ( screw holes are hidden by the stainless washer )-----------Nobody knows what your expertise is on doing work like this.-------But ask questions before you use a big hammer or prybar.----This outboard work is not hard to do !
 
My expertise is novice. no experience. I called the guy who sold me the engine before I put time and money inot this. He said as you face the engine the coil closest is the top spark plug the other is the lower plug. He said he puts new points in as a general rule and (like you guys) that its most likely the coil. I asked him if it was hard to work on it, he said no but I should not have to mess with it. He put coils in, but sometime stuff happens. He said bring it to him and he'll get it running correctly.

So I am taking it to him tomorrow, and I am going to have him show me how to do the work.
 
We looked at the motor He got a good spark from both cylinders. Ran the motor hard in his tank. The flywheel almost came off. It was seriously loose, (no I never touched it) So that may have been the issue, checked points (new) coils and condesor are all new as well.

Torqued it down really good (no we did not use a torque wrench) Fire it up and seems to run better now, nmade a few adjustments for idle etc...

Cautiously optimistic but always ran well in a tank. We'll see when I get it back on the lake.
 


I got a chance to take it for a spin with the wife and kids today (4/26). It ran better

With the whole gang it ran around 7mph throttle wide open, but unevenly. So I tottered around bit came back to the dock Kicked everyone out and took it for a spin with just me It ran ok got up to eight almost nine MPH ran but unevenly,hesitant loss of power almost seemingly almost stopped. So I went back to the dock and picked up my two little guys (total of maybe 70 lbs)I ran out from the dock and the motor smoothed out purred like a kitten and flew along a almost 12MPH and climbing. It was doing well

I thought perhaps it needed to be wrung out a bit. after being idle etc... It did well and was very confidence inspiring. Then boom uneven again and sank down to about 8 mph. Ran back to the dock and put my oldest (almost 100 lbs) ran out 8-9 mph but unevenly. Its an old (1973 low compression engine I've no idea how fast it should be, but it ran uneven. I am going to get some non ethanol fuel for it. When it ran smoothly it was great.


Thoughts?
 
ran it (no carb rebuilt yet.) Still hesitant. So a carb rebuild is in the works.This is something I will not take on myself. so...off to the shop. what does it cos?. I got 7-8 mph with two guys (approx 350 lbs) I took the motor on a approx 10 mile round trip jaunt today down the inner coastal water way in NC (bouge sound) the fuel has sea foam in it and I ran it previously at home with sea foam in it. The motor runs quiet and does not smoke much. Just loses power. I thought for sure it would quit for sure a few times.

You can feel the engine want to surge and go faster...


so a carb rebuild is in the works. in a tank it runs well. but under load not so hot.

what does a carb rebuild cost?
 
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