99 yamaha s200 txrx carburated

[soeedshop5]

I have issue on a 99 Yamaha s200 txrx carbureted engine runs great 5200 rpm for several miles then starts dropping rpm to 3800-4000. Once the boat is set down it will not take off turns around 3000 rpm. Things I have done complete fuel system clean tank, replace pickup and lines rebuilt carbs. Replaced stator because ignition coil was burnt. Also replaced ecm (ouch) because it was acting like it was a timing issue. you can go down the lake with a timing light and you can see the timing go crazy. Pulsar coil, regulator and crank shaft sensor all check good. I am lost on this one. Any help would be appreciated.

[TownsendsFJR1300]

What exactly is: "the timing go crazy" ??

[soeedshop5]

When it happens the wide open timing mark can not be found unless you dial it back in with timing light

[99yam40]

so it advances way too far,so it does not show up on the timing marks?

[soeedshop5]

Yes it does and when it does this like it drops cylinders. When it does this I have checked and made sure each cylinder is still firing

[99yam40]

I have never heard of a motor advancing the timing too far before.


do you have gauges that will tell you if the motor overheats or low oil shows up?

Do they work OK?
does the alarm buzzer work?

just trying to make sure the motor is not having a problem that you should be notified about with proper operating equipment

[soeedshop5]

Yes motor runs around 130 and oiling system is working warning buzzers are working

[soeedshop5]

[soeedshop5]

Can a pulsar coil check good them after it runs checks bad? I think I know the answer but just wanna make sure.. also new on this forum can we ask for used parts???

[99yam40]

I do not see why any electrical parts would not fail when heated up.
but not sure how often that has happened to a pulser coil in the past.

the host of this forum sells new parts, so it would be best to search for used parts elswhere

[soeedshop5]

Would the host be boats.net?

[99yam40]

that is what you get when you click on the Yamaha parts up on top?

[soeedshop5]

Ok I have a account with them already thanks

[panasonic]

Couple of Questions. It happens when the engine is hot, how long after you shut down till you can get it to work properly again?
Have you checked peak voltages in and out of the CDI using the proper attachment for your meter? Done both with the engine cold and hot?
I see in your picture a Clymer manual, do you have the proper Yamaha manual? If not ..I would get one.

Have you looked closely at the wiring from the timing plate for chafes or overheated wires?
Finally did this start happening after the coil and stator you replaced?

Sorry for all the questions, but many questions can lead to an answer.

[99yam40]

testing while the problem shows up is the best way to find a problem.

was it a new stater or used?

did you mean you had a burnt charge coil(instead of ignition coil)?