200 hp Johnson runs, but has a few problems
 

Hello group,

A few weeks ago I posted about my engine smoking like a train. I got
this problem fixed with a new VRO, lines, etc.... Now the motor starts
fine, idles, and runs. I took the boat out on Sunday for a shake down
run and had a small problem. Started at the dock fine, idled out of
the marina fine, but after about 5 minutes of running at 4000 rpms the
motor falls on it's face. No power and will not rev up. Well it revs
in neutral, but in gear only to 2500 rpms. I took the cover off and
the engine did not feel hot. I could keep my hand on the heads, just
felt warm.

I drove the boat back to the dock at 2200 rpms and stuck it back on the
trailer. I did some research on this group and it seems to be the SLOW
warning system coming on. I did re-connect each temp sensor (tan
wires) while working on the motor. When I got the boat these wires
where disconnected! I wasn't thinking on the water, but I should have
disconnected these sensors. What else can cause my problem? No horn
alarm, 2500 rpm max in gear, revs in neutral, idles fine, runs good to
2500 rpms, WOT makes the motor bog (lean?), and starts easy.

I also removed and cleaned each carburetor. Tons of crap in the bowls
and floats where a little low. While putting the carburetors back
together I did notice that all the jets are different. Not one carb
has the same jetting. I know this cannot be correct. Also one
carburetor (venturi) is bigger than the other 5. Does anyone know the
standard factory jetting for this motor?

The motor is a 1991 200hp Johnson VJ200TXEIB running at sea level.

thanks,
-Terry Quan

Tquan wrote:
Hello group,


I also removed and cleaned each carburetor. Tons of crap in the bowls
and floats where a little low. While putting the carburetors back
together I did notice that all the jets are different. Not one carb
has the same jetting. I know this cannot be correct.

You won't believe it, but this is correct. And it varied some
year-to-year. Consult a manual for your year.

Also one
carburetor (venturi) is bigger than the other 5.

No way. Even if a carb was changed out(there were 2 different size
carbs used on the 90 deg. V-6's) both venturis would be the same on each
carb. How are you "measuring" the venturi size? The venturi size is
stamped or machined on each carb body somewhere(going from memory here).



Does anyone know the
standard factory jetting for this motor?

It varied some year-to-year. Consult a manual for your year.

Rob

Hello group,


I also removed and cleaned each carburetor. Tons of crap in the bowls
and floats where a little low. While putting the carburetors back
together I did notice that all the jets are different. Not one carb
has the same jetting. I know this cannot be correct.

You won't believe it, but this is correct. And it varied some
year-to-year. Consult a manual for your year.

I can see it vary a little, but I have some with #31, #28, #50 etc...

Also one
carburetor (venturi) is bigger than the other 5.

No way. Even if a carb was changed out(there were 2 different size
carbs used on the 90 deg. V-6's) both venturis would be the same on each
carb. How are you "measuring" the venturi size? The venturi size is
stamped or machined on each carb body somewhere(going from memory here).

The throttle plates/body are the same, but the vent on that one carb is
bigger. It almost looks like someone broke a carb and stuck this one
on. You can see with the plain eye that one vent is larger than the
other. With this carburetor the vent is larger than the throttle
plate.


-Terry