4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

[Subliminal]

Hey guys,

I have a new (leftover 08) boat. I've clocked about 8 hrs on it, and it's had some issues:

1. It takes a couple of tries to get it to start and stay running. I pump the gas twice before I start it, and it usually starts, but then dies after running for a minute or two when I put it into gear.

2. It diesels a little when I kill it, sometimes.

3. Everytime I start out, whether I slowly raise the throttle or just gun it, it hesitates and then takes off.

4. I pulled a skier for the first time this weekend. There were 2 of us in the boat and a single slalom skier. The boat is 18 ft with 190 HP setup and it struggled to get the skier out of the water. My buddy's 97 18 ft searay with a 125 outboard pulls a skier out of the water faster.

Anyway, I have no ideas where to start to even think about tinkering with settings, but I wanted to ask the experts...which are you guys.

Thanks!

damon

 

[Don S]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

For one thing, you haven't even gotten the engine broken in yet with only 8 hours. Did you get an owners manual with it? Even left over 08 engines have Warranty, take it back to the dealer and have them check it out.

1. It takes a couple of tries to get it to start and stay running. I pump the gas twice before I start it, and it usually starts, but then dies after running for a minute or two when I put it into gear.

If it's a carbed engine, it's normal. It's a carb. Let it warm up first.

 

[wire2]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

Hey guys,

I have a new (leftover 08) boat. I've clocked about 8 hrs on it, and it's had some issues:

1. It takes a couple of tries to get it to start and stay running. I pump the gas twice before I start it, and it usually starts, but then dies after running for a minute or two when I put it into gear.
Carb or EFI? If carb, is the choke plate closed when cold?
2. It diesels a little when I kill it, sometimes.
What rpm does it idle at?
3. Everytime I start out, whether I slowly raise the throttle or just gun it, it hesitates and then takes off.
Is it warmed up to 160-180? when you do this?
4. I pulled a skier for the first time this weekend. There were 2 of us in the boat and a single slalom skier. The boat is 18 ft with 190 HP setup and it struggled to get the skier out of the water. My buddy's 97 18 ft searay with a 125 outboard pulls a skier out of the water faster.
You may be over-propped for skiing. What's the prop pitch? What's the rpm at WOT? Keep in mind, a 125 o/b weighs a fraction of your i/o system. Your engine is not broken in yet, it will gain a bit of power with run time. You're aware to vary the speed for the first ~25 hours?
Anyway, I have no ideas where to start to even think about tinkering with settings, but I wanted to ask the experts...which are you guys.
I don't claim to be an expert but I have been boating for 40+ years, have some experience.
Thanks!

damon

You're welcome

 

[wire2]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

Don, I had a feeling that if I took too long typing a response you (or someone) would get one in first.

 

[fossill]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

Sounds like the dealer never did a very good job on the pre-delivery inspection, if at all.
Take it back. It's an '08 so you probably have at least 2 years warranty on it.

 

[Subliminal]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

I have 5 years on the drivetrain, starting in mid-April. However, the dealer is 2 hrs each way from my house. My only other carbed equipment has been lawn maint. equip, but I've rebuilt a few carbs and noticed there are only a few basic adjustments on them. Wasn't sure if the boat carb was similar, so figured I'd ask.

As to your questions:

On break-In: He said he ran it in a pool for the initial 1.5 hr of break in and to test stuff out, but it definitely doesn't seem right...maybe I'm being over zealous after spending so much money on a new toy which is still foreign to me, but it just seems to run weird.

Don, It is carbed, and I do let it warm up for a moment or two...wasn't sure the starting was an issue, but I figured I'd mention it as coupled with the other stuff, it might have been pertinent.

Wire, it does this hesitation whether it's warm or not...whether I'm starting from idle or goosing it from a slow crawl.

Wire, the prop is whatever came stock. I haven't let it go to WOT yet, but it does around 50 GPS at 4300 rpm, and I believe redline is 4500 on that engine. I've been varying the RPM whenever I run it. For example, we drove 1 hr each way to Philly and I tried to change the RPM at least ever minute or two by a few hundred RPM.

 

[wire2]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

I have 5 years on the drivetrain, starting in mid-April. However, the dealer is 2 hrs each way from my house. My only other carbed equipment has been lawn maint. equip, but I've rebuilt a few carbs and noticed there are only a few basic adjustments on them. Wasn't sure if the boat carb was similar, so figured I'd ask.

As to your questions:

On break-In: He said he ran it in a pool for the initial 1.5 hr of break in and to test stuff out, but it definitely doesn't seem right...maybe I'm being over zealous after spending so much money on a new toy which is still foreign to me, but it just seems to run weird.

Don, It is carbed, and I do let it warm up for a moment or two...wasn't sure the starting was an issue, but I figured I'd mention it as coupled with the other stuff, it might have been pertinent.

Wire, it does this hesitation whether it's warm or not...whether I'm starting from idle or goosing it from a slow crawl.
Pull the flame arrester from the carb, look at the choke plate cold, then look again when the engine is up to temperature. Should be closed to start, fully open warmed. I suspect it's electric, make sure the wire is not off the terminal.
Wire, the prop is whatever came stock. I haven't let it go to WOT yet, but it does around 50 GPS at 4300 rpm, and I believe redline is 4500 on that engine. I've been varying the RPM whenever I run it. For example, we drove 1 hr each way to Philly and I tried to change the RPM at least ever minute or two by a few hundred RPM.

50 gps seems reasonable, the hesitation does not.
Maybe pull the plugs, compare the color/appearance one to another?

 

[security6]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

A thought regarding dieseling.

My folks had a Maxum with a carbed 4.3 mercruiser in it and it also dieseled. My dad took it in to the dealer and they gave him some suggestions because there was nothing mechanical to fix. Here are a few ideas:

1. Run a higher octane gas
2. Let the engine idle for a minute or two before you shut it off (idea is to lower engine temperature)

Besides that, we just learned to deal with it. It does seem to me that the 4.3 is prone to diesel more than other motors.

 

[fossill]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

If it's an '08 it more than likely has the TKS carb system.
My 4.3L, also an '08, can sit for a month and when I put it in the lake it starts up within 5 seconds with no issues.
If you're under warranty, don't touch it cause now there is an excuse to deny any present and future warranty claims because you tampered with it.
You also probably got a stock 23 inch prop. Mine did, I had it re-propped to a 4 blade 20 pitch merc diamond 4 to bring the rpm close to the upper limit. Gets on plane way faster and also runs way smoother.

Oops, disregard, I see you have the Volvo/Penta.

 

[6meter]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

Don't compare an I/O and a 125hp outboard for pulling skiers out of the water. I had a 20hp pull me out but my 4cyl Volvo I/O wouldn't. Normal. But a 4.3 should pull somebody up with no problems. Your hesitation issue is related to your power issue more than likely. Bring it back to the marina.

 

[Sparkinator]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

A buddy of mine just got a brand new Crownline 185 with 190 horse Mercruiser. It'll do 55 and looks beautiful, but won't get on plane with 2 tubes. He's ordering a 19 pitch 4 blade and getting rid of the 21 pitch speed prop. I gave him an old 17 pitch 3 blade he's gonna try.

Speed sells, and I understand manufacturers touting top speed on sales brochures, but if you want to pull skiers, that prop that will top out at 55, probably isn't very versatile.

JMHO

 

[mattb1974]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

it probably has 2 year old gas in it

 

[Subliminal]

Re: 4.3SX hesitation and struggle to pull skier out (8 hrs on engine)

I actually thought of that, but I've run at least a tank through it now. I was thinking of throwing a bottle of carb cleaner in with the gas, but hadn't decided if that was a good idea yet.