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sraab928
07-31-2012, 07:45 AM
Good Morning all - I am in the process of purchasing (under contract) a 2008 Mastercraft CSX 220 SS with an Indmar LY6 400hp engine. My question is this - when you first start the engine cold (not when its warm) the rpms go up and down (not sure of the range but its quite noticeable) for the first 15-30 seconds or so. I am told its the fly by wire controls setting themselves up. Since I have never owned a boat with this type of control I am curious if this statement is accurate. I searched the forum and couldnt find anything. I also looked over the Indmar manual on line and found nothing about it either.

I just want to make sure this is true before taking delivery.

Thank you in advance
Scott

CantRepeat
07-31-2012, 07:56 AM
Good Morning all - I am in the process of purchasing (under contract) a 2008 Mastercraft CSX 220 SS with an Indmar LY6 400hp engine. My question is this - when you first start the engine cold (not when its warm) the rpms go up and down (not sure of the range but its quite noticeable) for the first 15-30 seconds or so. I am told its the fly by wire controls setting themselves up. Since I have never owned a boat with this type of control I am curious if this statement is accurate. I searched the forum and couldnt find anything. I also looked over the Indmar manual on line and found nothing about it either.

I just want to make sure this is true before taking delivery.

Thank you in advance
Scott

I've never seen this as the default behavior in a throttle by wire system. Maybe Jim or EngineNut will have an idea as to why it is happening.

mckevin
07-31-2012, 08:54 AM
Might be ok... but mine doesn't do that at all.

sraab928
07-31-2012, 09:13 AM
It seemed like odd behavoir - the boat had been sitting - when we first started it - it would surge up and down for a short period than settled down. Upon warm restart it didnt happen. Now I have only witnessed the cold start once - I was told it was normal (because of the fly by wire) - but I really wanted to check it out before signing the final check as I cannot find anything about this online.

CantRepeat
07-31-2012, 09:21 AM
It seemed like odd behavoir - the boat had been sitting - when we first started it - it would surge up and down for a short period than settled down. Upon warm restart it didnt happen. Now I have only witnessed the cold start once - I was told it was normal (because of the fly by wire) - but I really wanted to check it out before signing the final check as I cannot find anything about this online.

Who told you it was normal?

sraab928
07-31-2012, 09:29 AM
The dealer.

sraab928
07-31-2012, 09:35 AM
I just called my local Mastercraft dealer (not the one selling the boat) and spoke to a service tech there who said that it is normal behavior for that motor. Not so sure why I didnt think to do that first.

Ironhorse
07-31-2012, 11:54 AM
Mine has always done this and it is only for about 15 to 20 seconds as you mentioned. It has never caused any other issues and my dealer said this was normal as well.

scott023
07-31-2012, 12:02 PM
I just called my dealer and they also said that is normal for the LY6.

sraab928
07-31-2012, 12:12 PM
Thanks guys - I feel much better now. I will post pictures of the boat when I get it home!

CantRepeat
07-31-2012, 01:00 PM
So it's normal for an LY6 but surely not normal based on throttle by wire.

scott023
07-31-2012, 01:03 PM
So it's normal for an LY6 but surely not normal based on throttle by wire.

That's right. Dealer said the MCX and L18 don't have that characteristic.

sraab928
07-31-2012, 06:10 PM
So I guess wrong explanation from the purchasing dealer but still the engine behavior is ok - Its good to know if anyone else is looking at one of these.

Coolerking
05-01-2014, 06:57 AM
Hi

I bought a 2008 XStar with only 150 hrs on it a couple of years ago. It has the LY6 Indmar 6ltr engine in it (Saltwater Series) and like you guys it hunted quite badly at cold startup (for around 20-30 seconds). Again, I was told that they all do it and not to be concerned.

Over the last 12 months the engine has progressively hunted more to the point that it stalled after a few hunts (5-10 seconds) meaning that I needed to provide additional revs to get the boat to run past the first 20-30 seconds. Once past the first 30 seconds the boat was fine all day.

I changed my maintainer to Maiden Marine in Crewe this year, and his (Mike) first comment was that as an Indmar specialist he didnít understand why it would hunt and had other customers with the same engine that didnít hunt, so it looked more like a common fault rather than a Ďfeatureí.

The first thing Mike diagnosed was that the fuel pump was failing. At first it was assumed that the previous owner ran the fuel tank dry at some stage but putting the engine back together (post service etc.) it started stalling again leading Mike to have concerns that the bleeding away of pressure was causing undue stress on the fuel pump and that the new one may fail soon.

The big question is, what is causing the pressure to bleed away that stops when the engine starts to warm and is about the engine being in a boat and not a truck?....

After many hours tinkering with components, fuel maps etc. Mike has diagnoses the O ring seals around the injectors. Because the routes/angles of the fuel lines into the engine are at strange and differing angles, it seems to be quite easy to get a seal that is bleeding fuel pressure. It would also seem that as the engine starts to warm that the expansion of the cylinder head makes the seal better.

Iím no mechanic and Iím sure Mike did a load of other things to the engine but a couple of things seem clear: 1) the wild hunting is not normal and 2) there is a common problem with the way the Indmar engines are installed into Mastrecraft boats.

If anybody out there has anything further to add please do as there maybe more contributory factors to the common fault on these engines.

I have yet to use the boat in anger this season. If anything further comes back I will post a message.

JamesL
05-01-2014, 11:51 AM
When I purchased my 08 with the LY6 I was told that it was perfectly normal for them to rev up and down like that for the first few seconds. I was told this by Eric from the boathouse in Chicago

willg
05-01-2014, 12:20 PM
I had a problem similar to this, it was the idle air control valve. Granted I have a much older LTR, but maybe something to check

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Forrest-X45
05-01-2014, 01:10 PM
Coolerking - Sorry but I disagree with your two points. What you describe behavior wise is normal behavior for a LY6. Mine does the same thing and has for years. As others have posted it is normal and my Dealer mechanics say they all do specially here on cool NW mornings. It is the cool morning air because mine won't do it later in the day on a first start if it is warmer out. It sounds like a drag engine idling with a huge amount of valve lift and squared off cam lobes. Gets everyone's' attention at the boat launch. :) Your second point is beyond believable. There are thousands upon thousands of MC's running Indmar engines without issues so having an install issue is crazy.

When the engine died after 15 seconds was this a one time occurrence or does it happen every cold startup? If it is one time caulk it up as that, one time. If the engine dies after 15 seconds every start then there is another issue. Throttle position sensor or MAF sensor???

Coolerking
05-01-2014, 05:31 PM
Thanks Willg / Forrest, just the responses I was hoping for. In reality I've no idea what the problem is, just repeating what the specialist is telling me, so anything you can add to shed some light on the problem is much appreciated.

Forrest, it did it every time once it started doing it. Yes agree re. the indmar's on MCs as the mechanic knows of indmars in MCs and non MC that work fine but he is saying the injector seal is prone to failure due to setup. Could this be a problem or unlikely?

I haven't tested it yet since the guy servicing it has fixed it. Will let you know how I go on but meanwhile I'm going to record your comments and pass them to the guy sorting it out. Many thanks.

1redTA
05-01-2014, 06:45 PM
sounds like a dirty IAC valve

1redTA
05-01-2014, 06:47 PM
dirty iphone

willg
05-01-2014, 07:06 PM
sounds like a dirty IAC valve

Yeah. I had this go bad on my MC and on a boat with a 454 Mercruiser motor. My MC LTR engine also had the throttle position sensor go bad and the boat would idle at 1000 rpm all the time. The valve is like $15 from the auto parts store. I don't know if a drive by wire boat has a tps sensor, but my money is something related to the intake air control or possibly the throttle body malfunctioning.

The symptoms on both were surging and stalling, cold or warm.

You can usually check the sensors, but they are so cheap its just worth replacing for piece of mind.

If you can figure out a gm car with the same motor, you can usually use it to cross reference parts at Napa/advance.

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willg
05-01-2014, 07:21 PM
This might be an interesting read, I know its an older boat, but he fixed his idle problem with a throttle position sensor

http://www.supraboats.com/bbs/showthread.php?1005-Engine-idles-too-high-sometimes-04-SSV

For what its worth, here's the IAC from bakes online ($220):
http://www.bakesonline.com/detail.aspx?ID=2410

and here is what I'm willing to bet is the same part from Summit ($70, they also have a cheaper one):
http://www.summitracing.com/parts/smp-ac147/overview/


And here is the MAP sensor
Bakes ($95):
http://www.bakesonline.com/detail.aspx?ID=1342

Summit ($50):
http://www.summitracing.com/parts/smp-as59/overview/make/chevrolet


I would think it was one of those. If you are at a dead end, it might be worth buying the cheapest one from summit and just changing them just to be sure. There are diagnostic methods for testing these components, but you are probably going to have to pay an hours labor to test them, its like a 2 minute job to just swap them.

CantRepeat
05-03-2014, 02:50 PM
No need to use the "toss parts at it method of diagnosis". There are tests for each of those parts.

JimN
05-03-2014, 03:27 PM
Good Morning all - I am in the process of purchasing (under contract) a 2008 Mastercraft CSX 220 SS with an Indmar LY6 400hp engine. My question is this - when you first start the engine cold (not when its warm) the rpms go up and down (not sure of the range but its quite noticeable) for the first 15-30 seconds or so. I am told its the fly by wire controls setting themselves up. Since I have never owned a boat with this type of control I am curious if this statement is accurate. I searched the forum and couldnt find anything. I also looked over the Indmar manual on line and found nothing about it either.

I just want to make sure this is true before taking delivery.

Thank you in advance
Scott

Shoot a video of it after sitting overnight, then e-mail it to MC and ask for their opinion.