Meltdown after resleeve. Machinist fault? What should I expect?

[CrazyJ]

Hey guys. After what seemed to be a successful rebuild, I took my OMC 115 crossflow out to the lake today. After about 15 minutes of fast idle and 3500 RPM, the boat loses power, warning horn comes on, I shut down immediately. We take it home, do some testing and pull the heads. Ends up #2 cylinder is scored badly and the side of the piston has rubbed aluminum all over the cylinder wall.<br /><br />Anyway, this is a cylinder that got resleeved over the winter. It also got a new Wiseco standard bore piston. There was still a crack in the block right outside the sleeve but the machinist said it was good to go. He was the one that actually encouraged the resleeve after I gave him the alternative to bore all 4 cyls of a different block. The cylinder scoring and melting happened in about a 1" wide path centered right on the crack in the block. I am fairly confident that the damage was caused by out of round cylinder or another flaw by the machinist. Does this sound reasonable?<br /><br />The machine shop is supposed to be the best in the area. I would expect them to take the blame and do some more machine work to fix the problem. However, as most of us know, the little bit of machine work required does not quite fix the issue of having to tear apart the whole engine, get new gaskets, pistons, etc.<br /><br />Also I'm not sure if I'd like to take my chances with this block again. I'd almost rather use the other block and get it bored and get all new oversize pistons. Of course the dealer isn't going to take back the 3 good standard bore pistons I just bought.<br /><br />So what should I expect from the machine shop? Are they going to buy me all new gaskets and pistons? Are they going to rebuild for me? Or are they going to tell me 'tough luck'? How should I approach this? What are they legally responsible for? Is any of this my fault? I live in Raleigh, NC.<br /><br />Thanks in advance for any help!

 

[OBJ]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

Man that is some bad news CrazyJ. But I would ask some questions here....<br /><br />Did you overhaul the carbs as part of the rebuild?<br /><br />How bad and just where was is the crack before the melt down and is the crack any worse?<br /><br />Are you sure the cooling system was functioning OK? Alarm working OK?<br /><br />The machinist only did the re-sleeving and I'm assuming you did the reassembly. Unless you can positivily say the fault is with the machinist, you may be out in the water without an engine.<br /><br />One more thing....did you replace ALL the pistons with Weisco?

 

[Dhadley]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

Why did the motor have to be rebuilt to start with?

 

[Freezebear]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

I had a friend with that same motor and had the SAME problem about a year ago. Just had his rebuilt with special high performance pistons and took it out and blew it very quickly. They told him that the thermostat had not been installed and caused it to happen and covered the repair. He still has it and is running fine. Good thing he let shop do the whole job or he would have been screwed.

 

[P.V.]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

Did you ever find a cause for the first breakdown? Did you rebuild all the carbs? Anything there? What year is the motor? How were the deflectors? Did you rebuild/replace the VRO? Did you test the VRO? Did you have 50/1 ratio in the fuel tank? What boat? WhaT PROP? what WOT rpms? Did you do a water pump job? Did you inspect thermos? Pressure relief valves? Timing? What quality fuel?????

 

[CrazyJ]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

Didn't touch the carbs with the rebuild. The crack is the same as before the meltdown. There is some of the old sleeve remaining between the cracked block and the new sleeve. Thats what makes the job look a little slack.<br /><br />The cooling system should have been functioning fine. The warning horn did come on at the end as it got hot, but I felt that it was hot because of the excessive friction, not a lack of cooling. Could this be correct? The inside of all cylinders seem lubed.<br /><br />All the pistons were replaced with wiseco.<br /><br />We rebuilt the motor because of the crack in the old sleeve and in the block. Had some issues before related to a rectifier repair going wrong. Check my old posts <br /><br />We had somewhere between 50:1 and 25:1 in the tank, plus VROs seem to be working. We weren't taking any chances with that! Boat is 94 Boston Whaler Rage 15 Jet. Prop is stock impeller, not very worn.<br /><br />We never got up to WOT. We were just breaking it in and in the motor manual it says that it needs a couple hours of really light throttle before running it hard. We haven't got to the timing because we did that at WOT last time. 93 octane fuel. Thermostats passed the test. We were getting good hard flow from the water exit stream in the back.<br /><br />After looking at it again, I don't know how anything else could be at fault. Of the ~44" of cylinder circumference of all 4 cylinders combined, the only bad area is near the crack on cyl #2. I drew something to illustrate it below. Obviously not a very accurate drawing though!<br /><br />

 

[Boilermaker]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

I'm no outboard engine expert>>but why would the machienest leave part of the old sleeve in there???<br /> I would think that would cause the cylinder to become out-of-round from the thermal expantion rates being differant in the area of the old steel/iron sleeve.

 

[Dhadley]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

A couple of things come to mind. If there was an issue on that cylinder before, the cause may still be there.<br /><br />Timing should be set as part of the installation. Whoever installed the powerhead should have done that before the boat gets put on plane.<br /><br />The carbs should have been rebuilt. Thats standard as is a new pump kit on any rebuild.<br /><br />The motor should be run on 87 octane, not 93.<br /><br />Now, a couple of questions -- What did the machinist use for a finished bore size?<br /><br />What spark plugs are you using?

 

[Duck Loads]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

If I understand this........Part of the old cracked sleeve was left in the block. A new sleeve was pressed in covering up the old crack leaving you with a new thin wall sleeve. Imagine having a crack in your sheetrock wall. You mud over it, and a week later the crack has propogated through the new mud. Dosen't sound good. good luck

 

[ledgefinder]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

The overheat alarm generally doesn't come on when a cylinder fails - particularly at light throttle like you were running. Sounds like a cooling issue that may be unrelated to the sleeve job. Sorry, CJ.<br /><br />I'm not saying the sleeve job was OK. My first reaction would be exactly the same as yours - sounds hokey. But I'm not an expert machinist and I may be wrong.

 

[KentBoyle]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

CrazyJ,<br /><br />I wish you all the best on your repair...<br /><br />Hoping you'll be able to give me a little advice... I purchased a 1998 jetboat with the 115/Turbojet configuration, and my boat also makes a terrible clunk noise, usually stopping the engine when it is at idle. You described a similar problem with your boat. At higher RPM's, the clunk noise goes away. How did you fix this problem? I would appreciate your advice!<br /><br />Thanks,<br /><br />Kent

 

[R.Johnson]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

For a machinist to bore out the sleeve,leaving part of the existing sleeve, just does not make sense, Where did the center line to the crank go? If you look at An OMC block, you will note that there is not much support between the cylinder wall, and the cooling outer jacket. These cylinder block's are not all that straight to begin with. This was pointed out by the man who rebore's our block's. He takes great pains to bore to the center line. He also stress's that the head be torgued properly, and retorqued after a short running time, We have not had any failures with anything this man has done.

 

[CrazyJ]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

Jade, I think the noise was especially bad for me when I had only 3 cylinders firing. The inconsistency would cause bad gear mesh. When I got all 4 firing, it got a little better. Still, when there is little load on the impeller, I get a some noise. Obviously, I have bigger problems here though <br /><br />I think there could have been a cooling issue, but isn't the warning horn supposed to be a "warning", not a "your screwed"?? I cut the engine immediately as the horn came on. I have read a lot and it doesn't seem that there should be damage at this point.<br /><br />It seems a cooling issue, compounded with the uneven thermal expansion, caused the meltdown.

 

[Dhadley]

Re: Meltdown after resleeve. Machinist fault? What should I expect?

The sensor for the cooling reads water temp not combustion temp. You could very well have a combustion temp issue (the cause of the previous problem, a carb problem etc) on that cylinder. The cooling water is OK but as the piston locks up, the motor quits and THEN the horn goes off. It all happens rather quickly.