ignition timing

[1stpriority]

Is there anyway to adjust the timing on a 1994 yamaha 250txrs. I looked in the shop manual from yamaha and cant find anything on it. I am assuming it is all controlled by the computer and if it is what would trip the computer to not let the engine advance all the way to 18btdc?

 

[rodbolt]

Re: ignition timing

any sensor failure can lead to high idle and timing lock at 7*BTDC.
a TPS failure will also.

 

[1stpriority]

Re: ignition timing

Thanks rodbolt, couple more things. I have the diagnostic light and hooked it up at idle with no codes being tripped. Can I leave the light hooked up and operate quickly at wot where the problem is to rule out any sensor failer? Can I run the boat at wot with air cleaner off and squirt mixture of gas and oil into each carb to see if it possibly leaning out or kill the motor with lanyard switch while at wot and pull plugs to see which if any are white from leaning problem? Thanks Rodbolt

 

[rodbolt]

Re: ignition timing

yes
yes
I dont reccomend it.
with the test lamp installed automatic oil transfer is prohibited.
manual transfer and alarms still function.

 

[1stpriority]

Re: ignition timing

Can I run the boat at wot with air cleaner off and squirt mixture of gas and oil into each carb to see if it possibly leaning out or kill the motor with lanyard switch while at wot and pull plugs to see which if any are white from leaning problem? Thanks Rodbolt

 

[rodbolt]

Re: ignition timing

yes but there is no air cleaner.
yes but read the above about the oiling system.
I dont reccomend pulling the kill lanyard at high speeds not only is it hard on the gearcase but can leat to flooding the bottom cylinders with water.