Gentlemen,
I have a 2008 Yamaha HPDI that has had religious,routine maintenance. On a recent trip I noticed it started idling lower than normal. I could hear the change in rpm. After a few minutes it stalled. I started it right up and hauled tail with no problem after it bogged down for 5 seconds or so… I ALWAYS idle in neutral and never shut it down. A friend thinks im fouling plugs idling all day… Am I wrong?
It’s possible that you could be fouling plugs. It should be simple enough to look at the plugs and see if they are fouled. I would probably change the plugs at least every season on that motor. When were they last changed? You should be able to idle in neutral all day.
Easy,
The plugs are brand new. Saturday was the first trip on them. I noticedit idle down over the summer while I was offshore spadefishing. It never died that time because I headed in. Saturday was the first time its ever stopped running. It cranks right back up though with no ossues.
Capt. R. Killin
21 Contender “Killin Time”
So it only does it at idle?
Never while cruising?
KILLINR ; CHECK THE FUEL PRESSURE TO THE INJECTORS , MAY NEED TO CHANGE/CLEAN THE HIGH PRESSURE FUEL FILTERS…
George McDonald
US Navy Seabees,Retired,
MAD, Charleston Chapter
[http://www.militaryappreciationday.org
When you see “Old Glory” waving in the breeze, know that it is the dying breaths of our fallen hero’s that makes it wave.
author unknown
High Pressure Pump and or filters
Tall Sail Marine
I remember reading something about “indexing” spark plugs in outboards. Did you index the new ones?
ZX
Yes only at idle but after an extended period. If I crank it now it will fire right up and idle perfectly. I did not index the plugs.
Capt. R. Killin
21 Contender “Killin Time”
Are you sure the idle is going down?
Or maybe does it lose a cylinder and start skipping?
It sounds like the idle just gets lower and lower until it shut off. It fired right back up and ran fine after. I earn it the next day, shutting it off when id arrive at my spots and had no issues. I hope it’s not losing a cylinder!
Capt. R. Killin
21 Contender “Killin Time”
quote:
Originally posted by killinRIt sounds like the idle just gets lower and lower until it shut off. It fired right back up and ran fine after. I ran it the next day, shutting it off when id arrive at my spots and had no issues. I hope it’s not losing a cylinder!
Capt. R. Killin
21 Contender “Killin Time”
Capt. R. Killin
21 Contender “Killin Time”
I believe it’s only the e-teck you need to worry about indexing to plugs. I would check my fuel lines and water separators and filters. Years ago I had a similar problem. It was the fuel line separated & the inside was collapsing.
I am fragile.
Not like a flower.
But like a bomb.
Well I know sometimes a coil pack will over heat and cause 1 cylinder to misfire. I’ve had that problem before and I could shut it off and it would start back up normal. That’s why I asked. Probably not the case with yours because it only happens at idle.
quote:
Originally posted by easyridingwoWell I know sometimes a coil pack will over heat and cause 1 cylinder to misfire. I’ve had that problem before and I could shut it off and it would start back up normal. That’s why I asked. Probably not the case with yours because it only happens at idle.
Sorry to hijack but I just had this happen to me and a key off and restart fixed it but dont think overheating was the issue since I had been drifting w/ the motor off for an hour when the problem occurred. Do you know a way to find which coil?
Chris
22’ Shearwater
Well, I put a new coil and an ignition tester in the boat and decided the next time it happened I would check each coil 1 at a time but when it happened I restarted the motor it ran fine and each coil tested good. I knew it would happen again so I just went ahead and changed “coil A”. I guess I got lucky and changed the right coil the 1st time. I haven’t had the problem again in over 30 hours run time and I am confident it is fixed.
Got it, thanks for help.
quote:
Originally posted by easyridingwoWell, I put a new coil and an ignition tester in the boat and decided the next time it happened I would check each coil 1 at a time but when it happened I restarted the motor it ran fine and each coil tested good. I knew it would happen again so I just went ahead and changed “coil A”. I guess I got lucky and changed the right coil the 1st time. I haven’t had the problem again in over 30 hours run time and I am confident it is fixed.
Chris
22’ Shearwater
That motor does not require indexing the plugs
that motor drops 2 cylinders when in neutral, and picks them back up when you shift into gear.
that motor is also computer controlled, so it will do its very best to maintain a steady idle.
for example, if 1 of the 4 running cylinders is not firing, the computer will compensate by increasing the fuel to the other 3 to try and keep the motor running.
sounds like you have an issue with one or more of the 4 idle cylinders.
Most likely if you had a fuel pressure issue or a filter obstruction, the motor will not run properly at high RPMS.
www.teamcharlestonmarine.com
www.bombislandboats.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING
Chris,
Id like you to check it out for me. Ill call then bring it down to your place to see whats up with it. Thanks
Capt. R. Killin
21 Contender “Killin Time”
ask for Brian
He runs the store for me
www.teamcharlestonmarine.com
www.bombislandboats.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING