Problem with Yamaha 200 @ higher Rpm

[yamaha200]

The motor is a 93 Yamaha 200, it has 250heads.

The problem starts @ ~3500rpm's, the engine starts to break up, almost sounds like it is miss-firing. I have already changed the......


pulsar coil,
all 6 coils,
and both fuel pumps,

and had the carburetors rebuilt,

None of the changes made have altered the problem in any way, good or bad.

Any info you guys can divulge would help tremendously. Running out of time and money for the boat.

Thanks in advance for your time and help.

 

[rodbolt]

Re: Problem with Yamaha 200 @ higher Rpm

you simply cannot have 250 heads, dunno who told ya that but you cannot.
your engine is a 2.6L and the 250 was a 3.1L and not much would interchange.you need to test CDI output AT the problem RPM with a peak reading multimeter and the specs from the tuneup spec guide.
for the money you have spent splattergunning you could have purchased some nice test equipment.
post a full model number and pictures of the powerhead.
gotta try to figgure out what someone has done to possibly frankenstien the motor.

 

[yamaha200]

Re: Problem with Yamaha 200 @ higher Rpm

you simply cannot have 250 heads, dunno who told ya that but you cannot.
your engine is a 2.6L and the 250 was a 3.1L and not much would interchange.you need to test CDI output AT the problem RPM with a peak reading multimeter and the specs from the tuneup spec guide.
for the money you have spent splattergunning you could have purchased some nice test equipment.
post a full model number and pictures of the powerhead.
gotta try to figgure out what someone has done to possibly frankenstien the motor.

My bad, i mixed up the info my dad was telling me over the phone.

It has 225 carbs and might have 225 heads, im not sure how to check.

here are some pics of the motor.

 

[rodbolt]

Re: Problem with Yamaha 200 @ higher Rpm

has it ever ran correctly with an RPM in the mid 5000 range.
if so then either we cant get fuel in a cylinders,bad carbs restricted fuel system.
or we have an ign miss.
that ign system uses a high and low speed stator winding.
test stator or CDI output at the problem rpm.

 

[yamaha200]

Re: Problem with Yamaha 200 @ higher Rpm

has it ever ran correctly with an RPM in the mid 5000 range.
if so then either we cant get fuel in a cylinders,bad carbs restricted fuel system.
or we have an ign miss.
that ign system uses a high and low speed stator winding.
test stator or CDI output at the problem rpm.

since its been in our possession, it has not run correctly over 3500rpm.