2003 Yamaha 115 HP 4 Stroke EFI Starting Problem

[JDPMN55125]

[QUOTE=TownsendsFJR1300;n217323]From post #18

Quote: " He removed and cleaned IAC Valve after the lake test" end quote..


Two things about this,

(1) Why did he clean it, as earlier noted, it's usually replaced-Yamaha does NOT have a procedure for "cleaning" it. And it SHOULD RATTLE when turning off and re-setting.
Testing it is easily done by a push of a button on the lap top while running and hooked up-idle can be raised and lowered testing the function of the IAC..

I do not know why he cleaned it.
I would speculate, (1) he has done this before on other motors (2) the ISC was replaced on this motor in 2012.


(2) The engine / issue was NOT tested AFTER he cleaned the IAC... That SHOULD have been done. Seems to pointing to an IAC not working correctly.

The motor was tested in the shop, running with YDIS software. The ISC opened and closed properly.
Then the owner and I took the boat on the water a few days later and experienced the same symptoms as before.

[TownsendsFJR1300]

[QUOTE=JDPMN55125;n217328]

From post #18

Quote: " He removed and cleaned IAC Valve after the lake test" end quote..


Two things about this,

(1) Why did he clean it, as earlier noted, it's usually replaced-Yamaha does NOT have a procedure for "cleaning" it. And it SHOULD RATTLE when turning off and re-setting.
Testing it is easily done by a push of a button on the lap top while running and hooked up-idle can be raised and lowered testing the function of the IAC..

I do not know why he cleaned it.
I would speculate, (1) he has done this before on other motors (2) the ISC was replaced on this motor in 2012.


(2) The engine / issue was NOT tested AFTER he cleaned the IAC... That SHOULD have been done. Seems to pointing to an IAC not working correctly.

The motor was tested in the shop, running with YDIS software. The ISC opened and closed properly.
Then the owner and I took the boat on the water a few days later and experienced the same symptoms as before.

Exactly.... It should have been TESTED on the WATER "AFTER HE CLEANED IT", where the issue is OCCURRING... It's NOT happening in the shop...

I would inquire as to why he cleaned it (and just being curious), and how, as it's not in the Yamaha shop manual and DOES NOT REQUIRE ANY MAiNTAINANCE...

And if I understand correctly, there is NO CHATTERING on shut down.. ???????

[TownsendsFJR1300]

Exactly... He "cleaned" the IAC AFTER the water test. It should have been tested on the water, BY THE TECH, AFTER cleaning.

Is there still NO chattering/re-set of the IAC after shut down?