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1976 - 10HP Chrysler hesitates to rev under load

H

Hofty

New member
Folks,

My 2 stroke outboard is struggling. Wondering if it might be an issue caused by the removal of the pull start mechanism (1 open screw hole) leaking air into the intake manifold or if it is timing related. I'm hesitant to think it's timing as I have adjusted it manually when under load and revving up whilst still have hesitation to accelerate.

Could also be this air hole on the engine side of carburetor?

See pictures Attached

2.jpg1.jpg3.jpg4.jpg
 
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The hesitation could be the position of the air/fuel mix screw???
You know how to set that screw?
The holes for the starter shouldn't go through the block, do
the starter fluid test for sucking air.
Start motor, spray SF around the intake side, everywhere but
right into the carb.
If that makes the motor run different??? then it's sucking air somewhere.
The tiny hole in the side of the carb is a low speed jet.
Clean the carb, no additives in the fuel until the problems solved.
Then the only thing added is Ethanol treatment or Sta-bil.
 
Sounds to me like it is running on one cylinder.----Just check and see if spark can jump a gap if 1/4" or better on both leads.----Sparkplugs are not used when doing that test.
 
racerone said:
Sounds to me like it is running on one cylinder.----Just check and see if spark can jump a gap if 1/4" or better on both leads.----Sparkplugs are not used when doing that test.
Click to expand...

So you were right disconnected the bottom plug and engine runs as it does with both connected. Now to figure out of it's the lead or the coil. Coils run at $120 CAD a pop which is unfortunate. Checked points and sandpapered the points. Think I broke my finger pulling starter Chord so off to hospital first.
 
Thanks for the video.
Racerone suggested running on 1 cyl. and it does
sound like running on 1 cyl.

At home running in a DEEEEP bucket, pull one plug wire at a time
and see if it stalls.
Then remove the flywheel and "file" the points.
I say file because the sandpaper doesn't always cut through the carbon
build up???
If the filing doesn't work?? try swapping the coils around and see
if the no spark follows the change?
The condenser can go bad too?? Try to swap them if the other swaps doesn't
work?
How's the finger??? :(
 
Update: So the one cylinder theory is correct. I have unplugged and checked the spark on the bottom cylinder which is there but very very weak. So action:

- Swapped condensers to check if that was the issue. Still runs on 1 cylinder just fine. And same weak spark on bottom spark plug test
- Checked resistance on faulty coil/wire. Did not produce good results or I'm not that proficient with multimeter so maybe I'm just not doing it right, so attempted to pull ingnition wire from coil BUT no success; it is hard wired from factory as one unit so cannot just replace the wire without getting whole new coil (stupid)
- Called local boat repair shops. $285 CAD a coil. But just found coil and ignition wire on eBay from reputable seller for $100 CAD so it arrives in 2 weeks.

In all honestly. I cannot think of any other fault other the the breaker point not contacting properly but there was weak spark when I performed spark plug test so not sure if it would be the breaker arm /points not connecting fully. I checked and appears they fully contact properly plus I applied 800 grit sandpaper on either side to smooth up surface of contaminants or rust.

What do you think now? I know Chrysler is an old and not the greatest motor but I'm attempting to make due with what I got.
 
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Update:

So I pulled the arm off with the points. It looks like there was a gummy substance on the points as mentioned in the previous comments. Only drawback now is that I destroyed the last ccoil so will report back in 2 weeks once new coil comes. Cannot hurt to add a new component but I will be using some electrical contact cleaner to brush up the point contacts to see if I can remove all residue.
 
There is nothing wrong with the design of these older Chrysler motors.------But just like any other old motor you have to learn to do the work yourself.
 
By chance did you do a compression test?

I'm with Racerone about the old Chryslers,
They're just as dependable as any Yam or Merc.
ANY motor can break down.
Usually the worst thing you can do is let ANY motor
set for any length of time.
 
Jerryjerry05 said:
By chance did you do a compression test?

I'm with Racerone about the old Chryslers,
They're just as dependable as any Yam or Merc.
ANY motor can break down.
Usually the worst thing you can do is let ANY motor
set for any length of time.
Click to expand...

Morning,

I have not performed a compression test. I am now awaiting the coil part so I can install that as I destroyed the previous one. It comes as a 1 part unit so the wire could not be separated from the coil. The new coil seems to have a independent wire and coil so it will be interesting to see now that the gum that was on the point is gone if a proper spark is apparent. The previous coil did not seem to add up with its multi meter test as per the other coil seemed to produce a reading. Maybe a combination of both were creating weak spark.

For the life of me it felt like the motor was running fine just not getting enough fuel or air mix ratio but now that I'm going to replace coil of she is running on 2 cylinders that should fix it with right air setting on screws.

My next job is to adjust the gear lever. It has 2 settings as it is adjusted. Neutral and fwd. No reverse. I fiddled with the arm and it does go into reverse without issue. So if this all fixes the motor. I'm going to be using her for the summer for trolling. It's extremely hard to come by a 4 stroke outboard deal where I live in Canada. People are seeking to sell even motorai in really poor state or repair for 30-50% of their cost new and the motor is 20 years old plus. Goes to show they have a strong resale value.
 
Took about 4 seconds on the video to determine it was on 1 cylinder.----Years ago I was at an ----" Wanna fix boats / motors shop "----Owner asked what i thought was wrong with a 1962 model 10 HP.----Running on 1 cylinder I said.------He spent time to explain that there was no way it was running on 1 cylinder.----Shop closed up about a year later.----He had no idea what he was doing.
 
My neighbor had a 9.9 Mercury on a 12ft.Alum. boat.
He said it runs ok just not as god as he thought it should.
I checked it over and laying in the bottom of the covers was a plug wire
that went to the bottom cyl.
Hooked it up and he was the fastest 9.9 around.
Lots of 2 cyl. motors rung good on 1 cyl.
 
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