| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 107.1 | Get it checked out | NRADM::WILSON | In the last days of bachelorhood | Wed Aug 10 1988 17:03 | 15 |
| Mark,
If the noise seemed to come from the powerhead, make sure you
don't have a case low speed pre-ignition or detonation. It can
be caused be low octane fuel, mis-adjusted timing or carburetor(s),
carbon buildup, etc. In severe cases the motor will actually skip
a beat and give a loud "thud" when the early combustion tries to
force the piston back down while it is still on its way up to
top dead center. I know my 40hp Evinrude will do this if I lean
the mixture out on the carb too much.
If this turns out to be your problem, be sure to get it fixed
quickly or you'll soon be asking us where to go for a rebuild.
Rick W.
|
| 107.2 | Mechanical or Electric shift? | ATSE::URBAN | | Wed Aug 10 1988 18:36 | 2 |
| Is this an electric shift Johnson? If so, I'll put in my 2 cents.
|
| 107.3 | | BTO::MILAZZO | | Wed Aug 10 1988 19:16 | 6 |
|
The shift is mechanical with two cables going back to the
motor.
Mark
|
| 107.4 | a better idea... | MAMIE::HAMEL | | Thu Aug 11 1988 16:32 | 10 |
|
Hay Mark,
Try getting a "real" motor.
"Hi!" from down south...
- Dean -
|
| 107.5 | We don't like those waves! | BTO::MILAZZO | | Thu Aug 11 1988 17:39 | 1 |
| Now at least mine starts Dean......
|
| 107.6 | ex | MAMIE::HAMEL | | Fri Aug 12 1988 20:20 | 7 |
|
I think THAT argument should be directed towards the guy that sold
it to me...
Hi Steve!
|
| 107.7 | Johnson Lower End Problem | TOOK::SWEET | Capt Codfish...Looking for Mr. Tuna | Mon Aug 15 1988 20:29 | 7 |
| I had a thud in my mercruiser when I put it in gear, turned out
a nut had worn down causing play in the prop shaft when it was shifted.
Basically the thud was the thing really going into gear, also the
shift cable needed adjustment. By all means have this looked into,
it sounds like a pay me now or PAY me later situation.
Bruce
|
| 107.8 | Johnson 20 outboard lower end problem | GOLF::WILSON | | Tue Oct 29 1991 13:07 | 18 |
| Moved by moderator...
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Note 926.0 Johnson 20 h.p. transmission problem No replies
WFOV12::DOBOSZ_M "Cogito Ergo Spud -- I Think, Ther" 12 lines 29-OCT-1991 10:32
--------------------------------------------------------------------------------
I was out in a friend's boat this past Friday and we had a drivetrain problem.
Here are the details:
The engine is a 1985 20-horsepower Johnson. We had been cruising along at
different throttle settings and the motor was running perfectly. Later in
the day, the transmission would suddenly disengage at about half-throttle.
The engine was running fine, but we were unable to keep the transmission
engaged at anything over half-throttle.
Has anybody experienced anything like this? We're still scratching our
heads over this one...
Mike
|
| 107.9 | A spun prop | ROBOAT::HEBERT | Captain Bligh | Tue Oct 29 1991 14:14 | 14 |
| It sounds very much like a "spun prop" to me. The propellor blade casting
is not connected directly to the sleeve that is driven by the gearcase
shaft, but is actually connected through a rubber grommet and sleeve.
Frequently, the bond between the rubber and the aluminum breaks, with the
result being operation such as you described.
This construction actually prevents the shock of hitting a rock or hard
bottom with prop blades from being transmitted directly to the gearcase.
It also keeps some vibration from the spinning prop from being carried
through the engine, to the boat, to your feet/spine.
Replace the prop, and it should fix your problem.
Art
|
| 107.10 | The prop can be fixed | GOLF::WILSON | | Tue Oct 29 1991 14:54 | 10 |
| Art is probably right, it sounds like the rubber sleeve between
the inner and outer hubs of the prop has slipped. If the motor
reaches a point where it suddenly freewheels and the boat slows
down the prop is usually busted.
This can be repaired by a good prop shop though; you shouldn't
have to replace the prop unless it's already beat up. Do a
"DIR/TITLE=PROP" for info on prop repair.
Rick
|
| 107.11 | Clutch Dog???? | MR4DEC::DCADMUS | | Tue Oct 29 1991 20:41 | 17 |
|
IT MAY BE A SPUN PROP OR A BAD FORWARD CLUTCH DOG If the engine
"jumps" out of gear for an instant, the clutch dog and forwqrd gear are
bad and will need to be replaced. If the prop slows down and the engine
rev's up- it's the propellor.
The clurch dog is very common on the OMC motors- I mus have replaced
the dog/gear a half a dozen times on th various motors I've had. It is
a simple job if you are mechanically inclined, and parts should cost
around $75-$100 fro a 20 Horse.
If it's the prop- a $35 rebuld will fix that
Dick
Dick
|