Yamaha F115txrb Shakes at Idle

[Jaymz007]

Hello everyone,

I have yet another problem.

Initially, the motor was shaking while in neutral and in gear.

First checked the spark plugs and number one and two were fouled.

Changed all spark plugs.

seemed a little better.

Checked the engine with YDS and found 2 codes and fixed the 2 codes.

Now the idle came down a bit and it was running around about 850 +/-.

I believe the idle speed is correct but what would cause the motor to shake kind of hard.

I have read a lot on the forums about this issue and I did clean number 1 and 2 injectors.

This motor is a 2003 F115TXRB with only 83 hours on it.

Any suggestions or help would be greatly appreciated.

BTW did oil and filter change and all fuel filters were changed as well.

Thank you in advance.

[Jaymz007]

Update

I have cleaned the injectors and reinstalled them.

1) I unplugged the injectors one by one and number one and two didn't cause any difference in the idle.
2) I checked the spark plugs and number one and two were fouled.
3) I replaced number one and two spark plugs and retested.

Now when I Pull the electrical connectors to the fuel injectors number one and two make a little difference.

I pulled all the injectors and changed the order of them and placed one and two into position three and four and same for three and four into one and two.

it condition seems the same as before I changed the location of the injectors.

Now my question is when pulling the electrical connection from the injectors one by one, pulling injector one seems way less pronounced then pulling like number three and four.
Sames as pulling number two but, number two is a little more pronounced then one.

So is it supposed to be like that or does it all need to be the same when pulling each connector?

Thank you
Jaymz007

[TownsendsFJR1300]

"Disabling" each cylinder one at a time (by ignition or fuel injectors) should result in the same "lesser performance" in a proper running engine.

850 RPM idle sounds kinda high but I'd be checking for actual spark at # 1 and #2 cylinders.

What codes (issues) popped?


.Also quote: " (2) I checked the spark plugs and number one and two were fouled. ". end quote.. That indicates fuel IS making it to the cylinders however fuel is NOT being fired off (no spark)...

.

[Jaymz007]

Thank you for your reply

When pulling the injector connector on number one the idle seems to weaken less than pulling number 4.
By that I mean when you pull the number 4 you can notice a big difference in how the engine idles vs number 1 which makes a very little change. in idle.

I just ordered the spark plug gap tester so I will have to wait to test for spark until the tester comes in.

There are no codes as of now.

The weird thing is the engine runs fine all the way up through the RPM.

This happens only at idle.

Which is causing my motor to shake at idle.

Thank you
Jaymz007

[99yam40]

you said it had 2 codes and you fixed them.
we have no idea what codes or how you fixed them

a timing light will tell if you are getting pulses to the plugs