Need help Don. 225 PRO XS-Motor has a slight miss at idle. Worse now.

[06champ198]

We had temps of 98 and heat index of 108. The motor did a few funny things. Hit the key to start it and it would fire then die. Hit the key again and idle normal. Seemed a little slugggish. My partner also has a PRO XS and he noticed it also. If I give it a little throttle just to get it to about 1000 RPM seemed smooth. Could I have gotten some bad gas? I run Quickcleen and Marine Stabil. It ran fine on the top end with no issues. Once started it never died and I had no alarms of any sort. Could it be time for some plugs? Just reached about 125 hours. It has always had a slight little miss but it seemed to really be worse over the weekend.

Thanks

[EuropeanAM]

Definitely time for a set of plugs.

In warmer weather, you MAY find better idle quality with mid-grade (89 octane) fuel. Don't run anything higher than 89 octane, however.

Probably a combination of heat, bad fuel, and spark plugs overdue for replacement.

[nightbasser]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EuropeanAM &raquo;</TD></TR><TR><TD CLASS="quote">Definitely time for a set of plugs.

In warmer weather, you MAY find better idle quality with mid-grade (89 octane) fuel. Don't run anything higher than 89 octane, however.

Probably a combination of heat, bad fuel, and spark plugs overdue for replacement.

</TD></TR></TABLE> + 1

[mikepags]

We had temps of 98 and heat index of 108. The motor did a few funny things. Hit the key to start it and it would fire then die. Hit the key again and idle normal. Seemed a little slugggish. My partner also has a PRO XS and he noticed it also. If I give it a little throttle just to get it to about 1000 RPM seemed smooth. Could I have gotten some bad gas? I run Quickcleen and Marine Stabil. It ran fine on the top end with no issues. Once started it never died and I had no alarms of any sort. Could it be time for some plugs? Just reached about 125 hours. It has always had a slight little miss but it seemed to really be worse over the weekend.
Thanks

had the same thing happen to me last week..........I am within about 10-15 hrs of a 100hr service..........did you notice your water psi was a little off as well.......mine has been off by about 1-2 psi depending on the speed...........

[jxb9723]

My past 3 opti's have had a slight miss at idle. 2004 225, 2001 200 and a 2006 225 Pro XS. Usually the miss is worse after you have been fishing for awhile and are idling to warm it back up. After an on plane 3000 rpms and above run and then back to idle is seems to be smoother. But you gotta remember this is still a 2-stroke engine. Its not a car engine. If the idle is somewhat smooth then it is fine. If it runs good otherwise with no performance decreases then I wouldn't worry about it. You need to ride with somebody that has an hpdi and you will think your Opti is a sewing machine. Those HPDI's cough and spit. I know how it is having a 15k motor and being paranoid about it. I used to listen to every little thing my engine did. Now I just run it hard and as long as its performing and the warning horns are not going off. If its not broke then run it like you stole it and feed it good fuel and oil!!!

[alabamaphoenix]

Don, what is the downside to running gas with an octane rating higher than 89?

[EuropeanAM]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alabamaphoenix &raquo;</TD></TR><TR><TD CLASS="quote">Don, what is the downside to running gas with an octane rating higher than 89?</TD></TR></TABLE>

1. Running higher octane (higher than the engine was designed to run) can result in an improper burn of the fuel. Improper (or incomplete) combustion will result in carbon buildup, both on the cylinder head, AND on the piston. Over time, these "carbon deposits" grown, and create "hot spots" on the piston crown. These can, over time, cause premature piston failure.

2. When refining fuel, it's more expensive to make a higher octane fuel. Hence, many blends utilize higher concentrations of Ethanol to "boost" the octane. More ethanol is CERTAINLY not something you want- we all have ENOUGH problems with that.

3. Because higher octanes burn slower and cooler, you would likely see a decrease in performance from running a fuel of "significantly higher octane".