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View Full Version : X-Star Problem...Please Help


rmbrinner
09-01-2005, 07:13 PM
My boat is making some awful noises. It has the 310 Indmar engine in it, with 350 hours. When you get about 1500 rmp's it starts making a clanking noise somewhere in the engine, then looses power, and backfires out the carberator.

Initially, we though it was the transmission, so it was sent off to Hurth Transmissions. Now the transmission is back in the boat and it is still doing the same thing it was before we sent it off. We can't figure out what is wrong.

Please, someone help. I would greatly appreciate any advice you could lend.

AirJunky
09-01-2005, 07:24 PM
Your in TN & you chose to send it to Hurth instead of MC? And are you sure it has a carb? I thought the 310 horse was EFI.
I think I'd get it into a dealer ASAP rather than trusting a bunch of clowns on the net.
Honk Honk

rmbrinner
09-01-2005, 08:58 PM
It is at the dealership in Memphis. They are the ones that have been working on it and can't figure it out. They sent the tranny to Hurth because that is who manufactured the tranny in that boat. The engine is a 310 hp Indmar Vortec.

So, any ideas? The dealer is asking me for any suggestions I can provide.

I would appreciate any ideas or things that I should check.

André
09-01-2005, 08:59 PM
No such thing as a carburator on an X Star!!!
You had backfires and power lost so you send the transmission to Hurth ?????????
I'm missing something here...

rmbrinner
09-01-2005, 09:00 PM
It doesn't have a carb, that is just the expression the mechanic at the dealership is using (don't know what he means by it, just thought someone on team talk might).

rmbrinner
09-01-2005, 09:01 PM
It wasn't my decision to send it to Hurth, that was the dealership's idea.

André
09-01-2005, 09:05 PM
Why would a defective tranny( i know,i know!) cause backfiring?
Is the engine reving fine over 1500 rpm in neutral ?

rmbrinner
09-01-2005, 09:07 PM
I don't know. Why? I guess I should ask the dealer that.

André
09-01-2005, 09:17 PM
Don't know either,my "i know, i know" was because i use the infamous " tranny" word...
But if your dealer is asking you for suggestions as for what the problem might be,the problem might be him.

FrankSchwab
09-01-2005, 09:45 PM
Hopefully JimN or EngineNut will chime in here....

The problem is going to be diagnosing "starts making a clanking noise" from a long distance away.

It could be a fuel flow issue - the "clanking" noise could be pre-detonation as the fuel mixture leans out; this might be in keeping with the losing power and backfiring symptoms.

It could be an overheating issue - the noise might be pre-detonation as the engine overheats. Does the engine continue to run after the backfire? If it dies, how long before you can start it and run it again?

It could be an electrical fault - perhaps the distributor cap (if your boat still has one) is bad, and the noise is pre-detonation caused by the spark getting shunted to the wrong cylinder. This might also be in keeping with the power loss/backfire.

Perhaps it's the ignition advance mechanism - it over advances, causing the spark to occur too soon and causing pre-detonation.

Okay, so much for the pre-detonation issues.

If its not the tranny, maybe it's something else mechanical. Perhaps the engine mounts are loose, and the engine block rotates far enough at that RPM to hit something. Does the problem occur if you rev the engine in neutral, or only when you rev it in gear?

Answer as many of these questions as you can, and pray for enlightenment from the true engine gods that inhabit these boards.

Good Luck,

/frank

André
09-01-2005, 09:49 PM
Hopefully JimN or EngineNut will chime in here....

The problem is going to be diagnosing "starts making a clanking noise" from a long distance away.

It could be a fuel flow issue - the "clanking" noise could be pre-detonation as the fuel mixture leans out; this might be in keeping with the losing power and backfiring symptoms.

It could be an overheating issue - the noise might be pre-detonation as the engine overheats. Does the engine continue to run after the backfire? If it dies, how long before you can start it and run it again?

It could be an electrical fault - perhaps the distributor cap (if your boat still has one) is bad, and the noise is pre-detonation caused by the spark getting shunted to the wrong cylinder. This might also be in keeping with the power loss/backfire.

Perhaps it's the ignition advance mechanism - it over advances, causing the spark to occur too soon and causing pre-detonation.

Okay, so much for the pre-detonation issues.

If its not the tranny, maybe it's something else mechanical. Perhaps the engine mounts are loose, and the engine block rotates far enough at that RPM to hit something. Does the problem occur if you rev the engine in neutral, or only when you rev it in gear?

Answer as many of these questions as you can, and pray for enlightenment from the true engine gods that inhabit these boards.

Good Luck,

/frank
Good post Frank! You're in shape tonight! :worthy:

rmbrinner
09-01-2005, 10:27 PM
Thanks Frank. I am definitely going to tell the dealer to check these things in the morning. I hope one of them works.

I don't know if reving in neutral or reving in gear makes a difference - haven't tried it, but I will ask them to try it tomorrow.

PendO
09-01-2005, 10:35 PM
*** ... the dealer is asking you for suggestions, call M/C Corporate, ask them to reccomend a tech or a shop that uses their expertise, not the customers guesses.

Thanks Frank. I am definitely going to tell the dealer to check these things in the morning. I hope one of them works.

I don't know if reving in neutral or reving in gear makes a difference - haven't tried it, but I will ask them to try it tomorrow.

rmbrinner
09-01-2005, 10:40 PM
The dealer has been working with MC corporate too. They don't know what the problem is either. Corporate has told them several things to check, but everything Corporate has told them to check has ended up being fine.

east tx skier
09-01-2005, 10:41 PM
When my jeep did this at low rpms, it was the U-joint. Since that's not possible here, just for grins, reach down and check the engine mounts. If they were loose, it would clank. I honestly don't think this is the problem, but it would be a cheap thing to check.

On a side note, I'm no mechanic, but a carburetor is not an expression the last time I checked. Sure, TBI might be called a close cousin, but I can't imagine a MC dealer tech actually saying that. I suppose he meant the throttle body.

JimN
09-01-2005, 10:47 PM
Ask the dealer if you can see the certificates from MasterCraft Servece Training classes. If they have none, they're either a new dealer or they told MC they would get the certifications and didn't.

If the motor backfires, it could be a few things. A bad valve spring hanging up at higher RPM, a bent valve, bad plug wires creating a cross-fire situation, a bad ignition control module, or even a jumped/stretched timing chain or bad gear. I have seen and heard about some bad distributor gears, too. Have the tech remove the distributor and look at the gear on the shaft and also on the cam. He'll need to turn the motor over slowly and look all the way around the gear for broken/missing teeth. Bad transmission? Yikes! It should have been pretty easy to hear whether the noise was coming from the motor or transmission.

Are you the original owner of this boat? If you are and the problem started before the warranty ended, it should still be covered. Trouble is, the dealer doesn't seem to know what they're looking for. If they actually think there's a carb, call MC and go somewhere else. MC hasn't had a carb in a boat since '94. other than the Barefoot, which was an outboard.

Ask for full documentation for what they have already done in order to diagnose the problem. They need to check compression/leakdown , hook up the diagnostic computer to check for codes, take a fuel sample, verify the base timing, make sure the battery terminals are tight and clean, the grounds on the motor are tight and known to be good connections and make sure the cap/rotor/plugs/wires are to spec.

What is the service history for this boat? Have there been other major problems before, and have you taken it to this dealer the whole time you have owned it? Has the motor ever frozen from not being winterized properly? This could result in a cracked block and the back of the piston skirt may be catching on the crack in the cylinder. Not terminal, the block can be bored out and sleeved. They do this with race motors all the time.

Has there been a time where the motor stopped running after shutting it down, and water was found in the cylinders? If it has, it could be a bent valve(as I said previously, a bent connecting rod or a bad piston head. It would be a lot easier if the boat was in fron of me, but these are some of the things I would be looking at.

rmbrinner
09-02-2005, 12:20 AM
I bought the boat in Texas and Texas Mastercraft was the one who serviced it. I called and talked to them and they checked the service records and said there had been no major problems.

All this started happening at 350 hours - 15 hours after I purchased.

Thanks for all the suggestions. I am going to tell the dealer to check these things tomorrow.

Would be glad to take any other suggestions as well.

rmbrinner
09-02-2005, 12:39 PM
Thank you so much for all your advice. The whole problem was the plug wires being in the wrong order. It is running great now!

east tx skier
09-02-2005, 01:24 PM
I can't believe they pulled the transmission and sent it off and it ended up being the plug wires.

Rockman
09-02-2005, 02:28 PM
Thank you so much for all your advice. The whole problem was the plug wires being in the wrong order. It is running great now!


Maybe that's why the last guy got rid of the boat...couldn't figure out what was wrong...and fixed the tranny 3 times and still the same thing!? :noface:

AirJunky
09-02-2005, 02:40 PM
The dealer is asking the customer for suggestions? And they yarded the transmission out 3 times for a simple ignition problem?!
Don't the diagnostic computers the shops hook up the engine to spell out ignition wiring problems pretty clearly!?
Doesn't sound like a very competent dealer to me. Hope MC is taking a look at them, especially since their in the home state!

River Rat
09-02-2005, 02:47 PM
I would be worried about taking it to that shop for a real problem. :huh:


Sorry sir we can't locate the problem so you will have to buy a new motor and see if that fixes the problem! :purplaugh

amesgardner
09-02-2005, 02:47 PM
To clear, are you working with an actual MasterCraft dealer?

rmbrinner
09-02-2005, 04:51 PM
Yes, it is an actual Mastercraft dealer. But, to clear things up, they sent the Transmission off because it did have water in it. The seals did need replacement. It wasn't like they sent it off for no reason. It just didn't fix the problem I was having. But thanks to John, I now have a boat that runs correctly. Thanks again!

JimN
09-02-2005, 06:47 PM
OK, water in the transmission is a good reason to repair it. The firing order is awfully easy to check, though.

amesgardner
09-06-2005, 04:22 PM
Yes, it is an actual Mastercraft dealer. But, to clear things up, they sent the Transmission off because it did have water in it. The seals did need replacement. It wasn't like they sent it off for no reason. It just didn't fix the problem I was having. But thanks to John, I now have a boat that runs correctly. Thanks again!
glad it is working now....but I didnt see who John was. Someone at the dealer, or a post?

rmbrinner
09-07-2005, 10:08 AM
John was a post

Thrall
09-07-2005, 01:43 PM
Seems pretty suspect that the dlr couldn't find a crossed up firing order. Hope they didn't charge too much for that diagnosis/repair.
For future reference, your firing order for that engine and any of the older SB Chev motors is 1-8-4-3-6-5-7-2.

amesgardner
09-07-2005, 02:14 PM
i agree, the dealer should have been MUCH quicker with this. i thought plugs and wires are almost an automatic starting point.