82 Johnson 200 loss of power in water

mscarol · Jun 19, 2007

Have been battling problem for a couple of weeks. Motor runs well in driveway on muffs, but put it in the water and can not get the boat to run much past idle. Boat ran ok when I boat her used. It is on a 20' Pursuit WA. Was never able to get her above 4600 RPMS at about 35-37mph. So far have done the following:

changed plugs and wires
fuel water seperator
removed carbs, cleaned and kits
compression 90psi on left bank and 75-80psi on right bank
changed most fuel lines
dismantle fuel pumps and cleaned
coils ok
spark on each cylinder

I'm running out ideas, do have a manual and was thinking of changing head gaskets due to lower compression on bank and getting new fuel pumps, as I was told that once you take them apart they are now no good.

HELP Please.

Mario

fireman57 · Jun 19, 2007

Re: 82 Johnson 200 loss of power in water

Welcome to iboats! Is the spark on each cylinder a bright blue that will jump your spark tester over 1/2"? You also may need to set your idle while in the water as the back pressure will not allow it to idle as if it were on muffs. If you set your idle on the water I believe it should be somewhere between 650 and 750rpms. Someone will be along shortly to verify that.

mscarol · Jun 19, 2007

Re: 82 Johnson 200 loss of power in water

thanks for the reply. yes on the spark and setting the idle. will idle in water after 1st start. then try to run and can not get rpms above 2000-2500. then will have trouble with idle and have to mess with idle set, to keep running...

mscarol · Jun 19, 2007

Re: 82 Johnson 200 loss of power in water

Fireman,

Did more investigation on the spark and have not reported correctly. I have found that there is spark, but not to the extent of 1/2" or bright blue. I had only tried checking by placing a screw driver in the wire and checking against the block. I have made a gizmo to check the spark with 1/2" gaps and found that I don't get spark with this method. I would appreciate any more input.

Thanks,

Mario

emdsapmgr · Jun 19, 2007

Re: 82 Johnson 200 loss of power in water

Put a timing light on each plug wire and note the flashes when running the engine. Strong, weak, intermittent, or none. I would expect normal compression to be in the 105-110 range on that engine. Try running a can of Engine Tuner through it and see if the compression comes up any.

mscarol · Jun 19, 2007

Re: 82 Johnson 200 loss of power in water

will try your suggestions tommorow and post results. any specific engine tuner?

emdsapmgr · Jun 20, 2007

Re: 82 Johnson 200 loss of power in water

Bombardier Engine Tuner is avail at any dealer.

mscarol · Jun 20, 2007

Re: 82 Johnson 200 loss of power in water

Was able to get a timming light on it and didn't see any light. But again can put screwdriver in plug boot and see weak spark against the block. If I move the screwdriver away at all I lose the spark.

Haven't been able to get the engine tuner yet.

I am thinking electircal problem and am not sure where to start. Coils, power packs, stator, magnets?

Any help is appreciated.

Mario

iwombat · Jun 20, 2007

Re: 82 Johnson 200 loss of power in water

Does every hole exhibit weak spark? If so, I'd be running some tests on the stator. It could also be coils, but less likely to be all of them.

mscarol · Jun 20, 2007

Re: 82 Johnson 200 loss of power in water

Yes all show weak spark. Suggestions on testing the stator.

iwombat · Jun 20, 2007

Re: 82 Johnson 200 loss of power in water

I'll have to refer you to a manual, or someone who knows those procedures off the top of their head. You'll need a good electrical meter to perform them though.

fireman57 · Jun 25, 2007

Re: 82 Johnson 200 loss of power in water

You can do a search of the forum which should yield some results for you but the best would be to buy an OEM manual. If you are in a hurry you might check the library and they should have a manual that would help.

82 Johnson 200 loss of power in water

Cadet

Captain

Cadet

Cadet

Supreme Mariner

Cadet

Supreme Mariner

Cadet

Captain

Cadet

Captain

Captain