94 250 txrs problems 911 HELP PLEASE

Get a drink this is gonna take a while.. I have twin 1994 250 txrs on a 31 fountain. last season near the end i had an issue when trying to get on plain the starboard motor would go to 1500 rpm then just drop off and stall. if I kept trying eventually it would take off ang go. the problem was intermittin. it was end of season and that power head was coming off for rebuild any way. So i did the rebuild put everything back on and still had the problem. The power head I had on was just being used to get me throught last season I had picked it up and it had dished pistons where my port motor had domed pistons. at top end it was a 1000 less rpm's than port motor. I figured this was the dished pistons. But now the rebuild is complete I have the same problem. So I have put new fuel filter , 3 new fuel pumps, all 6 carbs gone through, all coils wires and CDI swaped with port motor, stator and pulser coil swapped. TPS checked good and was reset. external tank added to rule out tank issues. The port motor runs great with all the other motors parts so what is left on the starboard to check? I am at my wits end. I have talked to a few yamah dealers around and they all say im on the right track but no one knows ANY HELP PLEASE!!!!!

There is dirt in the carb between the fuel line nipple and the float seat. You need to blow it out from the seat towards the nipple.

I just did that I soaked the carbs in cleaner then blew them out and reassembled them even took all jets out for cleaning but thanks for you response

Unless you blew air from the float/needle seat back towards the fuel line nipple there is debris blocking the fuel flow intermittently.

Just a guess but you may have a high speed charge coil that is breaking down. Someone should do a peak output test on that. Has your battery charging been diminished? That is frequently affected first and then then the whole stator starts to fail. Did you put new parts in this?
Have you done a fuel system vacuum test at the line after the check valve under the cowl?
Has anyone plugged in a test light and checked for codes?

I swapped stators no change dont have a vacum tester and and dont have a wink blinky bbut have swapped almost all electronics

OK I have swapped the carbs with the other motor also swapped the crank position sensor, fuel regulator and TPS no change ANYONE ANY IDEAS???

Sounds like fun, wish I was there. I left my brain unsupervised and it woke me up at 3 am with some off the wall possibilities. There are primers on each carb which enrich for starting and knock suppression. So, have you tried disconnecting the knock sensor? Is there a wire harness issue causing the primers to actuate? Could maybe isolate them once you have the motor running. Just guessing from this distance. What happens to your timing when rpm reduces. Is your rpm reduction kicking in? Have you grounded a heat sensor lead to see if the alarm actually functions. I've seen that happen and because of a faulty buzzer you don't suspect alarm mode. Alot of things point to your wire harness unless you have eliminated that.

the 1st thing do you run each engine off diff gas tanks

Steve

both engines are on same tank have not tried to discontect knock sensor not sure where to start with harness I agree with the primers i was thinking that my self but was not sure how to check it so all i ahve to do is disconect the knock sensor? what about voltage regulator?

Are your tank using the same pick-up...or do you have one for each motor

Steve

Voltage reg not the problem.

OK update still have problems but here is what i have done swapped all 6 carbs swapped knock senser swapped tps no change so I swapped the carbs back but not before removing them and cleaning them again and blowing air backwards from needle to inlet. Now have noticed something and its on this motor only when the motor is idling if I hit the trim button the motor trims and the motor idles very rough then when i let of trim button motor stalls. not while trimming but after button is released this is why im leaning to something with voltage.

I hope you have a battery for each engine, if so you have a bad cell in that battery, or voltage is very low from not charging from that engine

Steve

Your ECM needs adequate voltage and you have changed out everything but the wire harness. If that motor was here I would be stripping that harness from the voltage source on the port side to the ECM. Looking for any connection in a red or yellow wire that isn't clean and shiny.

Ok I went and bought a vacum gage hooked it up between the check valve and fuel pumps just like the manual says manual says I should have between 4.5 and not to exceed 6 in Hg im at 5in Hg looks good to me next im going to swap wire harnesses I think this is gonna tell the tale i keep getting this thing running and I think I have fixed it then I goes back to runnin rough I have been thinkin all along a broken wire just because its intermittin HEY PBRMAN come to Detroit ILL BUY ALL THE PBR U CAN DRINK wish me luck im missing summer

Thanks, and fingers crossed on that harness.

one other thing i noticed my trim indicator on my digital tach is reading drive all the way up no matter what position its in and the top bar flashes is there a way to adjust the trim indicator? if so where is it

It's up inside the port transom bracket. Probably stuck fully actuated. You may be able to spray some silicone lube on it and work it free.