1988 30hp yamaha breaking dowr

[sambrigman]

this motor will take off, run wide open for a couple hundred yards then start choking down will not take gas, idles ok but will not go. acts like timing is out. can stop for a while it will go a little ways then mess up again. I do not where to start. plugs look good any suggestions or ideas greatly appreciated!! thanks guys

 

[brodmann]

When it dies, is the primer bulb still hard? Try pumping the primer bulb while it's running and see if that helps. If it runs fine as long as you pump the primer bulb, you need a new fuel pump.

 

[sambrigman]

yes, bulb is hard, it is not a fuel problem, im afraid it is more serious

 

[99yam40]

overheating maybe.
does this rig have an alarm that functions?

 

[sambrigman]

not over heating

 

[99yam40]

How do you know it is not overheating?
do you have gauges and a warning alarm that works, that you have tested to make sure?
Is this a oil injected motor or a premix?
since you think timing is a problem, have you put a timing light on this motor to see if timing is in spec but changes when the problem shows up?
You can also test peak voltages into and out of the CDI when it is running well and again when the problem shows up to see if any of those change.

 

[sambrigman]

motor stays cool to the touch. it starts and runs perfectly too good to be timing. cdi advice sounds like it may be the problem, will test thanks