Boat is a 2006 Svfara SV609, with a Mercruiser Black Scorpion 5.7L. <BR> <BR>So, today, got it back on the water today after replacing my prop. Filled it up with marine gas before getting to the lake. Got out, and as soon as there was a load on the engine, it would start to miss, and run like hell. So did some research myself, Mercruiser says to run 87 octane in it. I called the station that I got the gas from, and the gas was 92 octane. This is only the 3rd time the boat has been on the water since I've owned it. When I took it out the first time, was my test drive with the dealership, then 2nd time, I added $40 in gas, then $55 in gas the 3rd time. <BR> <BR>So, was the higher octane gas that I ran not good for my engine? The 2st and 2nd time I had it out, it ran like a champ, no issues at all. So, now all of the original dealership gas has been run out of it, and its got straight 92 octane in it. Is that the cause of my problem? <BR> <BR>2nd problem is with the surge brakes on my trailer. Trailer is a ShoreRider tandem axle, drum brakes. When the brakes are applied, they make an awful grinding noise, like something is between the shoe and the drum. When I pulled it out of the water it was fine, then once I drove it into town, they started grinding again. <BR> <BR>Thanks in advance for anyone that might have any ideas!!

as far as octane goes the numbers in the manual indicates the minimum octane level you should run. 92 octane should not in any way cause trouble when 87 is recommended. <BR>Checked the brakepads on your trailer? If they're worn or a bit out of allignment you might get that screeching metal on metal noise

Everything is covered under your warranty. Take it back to the dealer and let them handle it. The gas would only be causing the issue if it had water in it, or in very rare cases had too low of an octane.

Running super in it isn't going to make it miss and sputter. <BR> <BR>I'd take that trailer to the dealership.

Thanks guys. Guess that's the problem with buying the boat from a dealership that's a 7 hour drive away. A long way to go when you need warranty work done! <BR> <BR>So, do you think my first course of action should be to get rid of the gas that's in it and try new stuff? Like I said, it ran 100% the time out before, and its only got 72 hours on it.

I talked to my dad today, he was with me when we had it out the other day. He explains it to me as - when you give the motor power, it bogs down and just doesn't want to throttle up. It wouldn't be a cylinder mis-fire at all. Hope that helps if anyone has any ideas.

is there any way the gas you put in was contaminated in anyway???? if maybe then yes change out the gas. <BR>a higher octane gas than required only wastes your money it won't do anything else. <BR>any mercruiser servicer can do the warranty engine work <BR> <BR>the trailer, it may be ok, when newly adjusted the shoes should just barely be contacting the drum and you might hear a schoosing kinda like grinding but smoother...jack it up spin the wheel check it out pull the wheel and the drum and inspect fix as neccessary <BR>hope this helps

Sounds like possible bad gas. If a dealer trip is out of the question, I would check the filter too. How long since the last time you had it out? Sometimes you can get water in the gas if it sits too long

I had it out first on March 23rd, 2nd time on May 5th, then again on May 19th. The time on the 23rd and the 5th, it ran 100%. Anyone have any idea where I can find the fuel filter?

Hi Jay, <BR> <BR>I'm also a Svfara SV609 owner (albeit a 2002). The brakes should not make a loud grinding noise when stopping. It could be something caught in the brake drum. Is it happening on both sides? Mine are louder than a cars, but not overly loud. <BR> <BR>The Merc engine in the boat is your standard MPI 5.7L engine supplied to a lot of boat mfgs. There are 2 fuel filters. One is the fuel/water separator located on the drivers side of the engine. It looks like an upside down oil filter. Remove it and empty out the contents. It may be full of water. The other fuel filter is an inline one, located below the one you just emptied. Just trace the fuel line from the pump and you'll see it. <BR> <BR>Good luck <BR> <BR>Trash

(Jay) May be the skinner valve starving the engine. <BR> <BR>Or the guardian system kicking in.

Hey guys. Got the fuel tank drained, put on a new fuel filter, new fuel/water seperator filter, and new tank of gas. Got it out on the water today, and it ran worse than last time. <BR> <BR>At an idle, it sounded great, up to about 1000rpm, it was great, then once it got up to about 1500-1700rpm, it started to bog down worse than last time, and miss really bad. <BR> <BR>What shall I check next? Fouled plugs are my next guess. I will check that tomorrow, I've got my mechanic buddy coming over to have a look.

Howies Marine and Apex Marine are listed by Mercrruiser as service places in Prince George. <BR>Warranty work on the engine should be available at any Mercruiser service centre.

Check the distributor cap. I have a Mercruiser in my Centurion, last year it started missing under load, I went through all of the gas and filter stuff, changed the spark plugs and it only got worse. Finally checked the distributor cap and rotor. There was lots of corrosion inside the cap that was causing misfires.

if you are running 92 the spark knock sensor is shutting the motor to gaurding mode. You can take it to a Mercruiser deal and have them put it on a computer to make sure. The motors acually run better on 87

I can't see it being Guardian at all. It will still rev up to wide open throttle, its just not happy when doing so. Guardian wouldn't let me do that, correct? I just talked to the dealership, and he said check the distributor cap as well, would be moisture or corrosion in there.

So I pulled the cap today, to find a ton of corrosion in there. Every point on the cap was corroded, and the top of the rotor was rusted. Cleaned that up with some emery cloth, put it all back together, dropped it in the lake, and she ran like new!! SO HAPPY!

get a new cap

A little more about the problem from a marine mechanic. In recent years Mercruiser started venting the cap thinking it would reduce condensation resulting in corrosion. Other manufactures use a sealed cap. The mechanic tells me he replaces alot more Mercruiser caps than any other brand. He suggest replacing the cap ane rotor every spring if you don't want to have problems on the water. The set cost about $40.

Its about an $80 replacement for cap and rotor. I'm gonna try it out now, I put some silicone on under the cap before I put it back on, so will see how well that works.

Jay, I just looked at my reciept $34.84 for cap and rotor from local marina last summer.

$64.00 for cap <BR>$12.60 for rotor <BR> <BR>The dealership here is a total ripoff! They charged me $75 for a fuel filter! But when they are all you've got, gotta pay what they want!

Mail order from west marine, boatus, skidim or any of the many parts distributors. I realy hope you didnt pay 75 for a fuel filter... Dealers are too proud of their stuff for their own good.

Bob, He is probably talking about the inline fuel filter, not the water seperator. The inline filter is difficult to find except from Mercruiser. Dealer MSRP is $40. There is a sierra aftermarket cross reference with an MSRP of $25 but I have never found it in stock.

He is in Canada so may be taking in "funny money"

It was $75 with tax for the inline fuel filter, and $12 for the water seperator. I found a Fram filter that was identical to the Merc one. Turns out the one end had different size threads on it, so it wouldn't work. Was happy that I saved myself $65, oh well, too good to be true.

The Mercruiser fuel filter (not seperator) is part number 35 864572T MSRP is $47. The Sierra aftermarket is part number 18-7721. It is the identical filter made by Racor division of Parker, I've seen this on the internet for $25. The Wix fuel seperator part number is 33225.

Yup, that's the one I spent $75 on. Oh well. I'll see if I can find the Racor one next time, that would sure be nice.