mercruiser advice

[01SeaRayBR]

Hi everyone, new to the site. I've been on here for a couple of weeks now doing research and I love it already. I need some advice. I just purchased a 2001 sea ray signature 230 BR with the 6.2mpi and bravo I drive. I think the motor needs a rebuild, but i wanted some expertise on the issue. It turns over but will not start. I have fuel at the fuel rail, and i have spark at all 8 plugs. I ran a dry and wet compression check and here is what i got:

Dry:

c8) 0psi c7) 110psi
c4) 80psi c5) 95psi
c6) 62psi c3) 90psi
c2) 80psi c1) 110psi

wet:

c8) 0 psi c7) 115 psi
c4) 95psi c5) 100 psi
c6) 80psi c3) 95 psi
c2) 120psi c1) 111psi

what you guys think?

thanks in advance.

Nic

 

[CobiaXL]

Re: mercruiser advice

Ya the 0 is pointing that way...Sounds like a valvejob at the very least.Might just have a stuck valve,pull rocker cover and tap on it to see if its moving.

 

[01SeaRayBR]

Re: mercruiser advice

What are your opinions for the other cylinders? Looks like the whole left side is having issues. What should the psi be in the cylinders on this particular motor? I looked in the service manual and is says 100psi. Does that sound right? I know its a 377 and not a 350, but i could of sworn i have read other threads where people were talking about having 150-160psi in their cylinders in a 350.

 

[cr2k]

Re: mercruiser advice

At this point it needs a pull down of the intake and heads to see whats going on. How is the oil? Full? Over full? Milky?

 

[01SeaRayBR]

Re: mercruiser advice

The oil looked normal, didn't look old at all. As for the Oil level, it was reading normal on the dipstick.

 

[mkast]

Re: mercruiser advice

Now is the time to do a cylinder leak down test, it will show you where the leakage is.
100 psi is minimum compression, it should be higher.

 

[01SeaRayBR]

Re: mercruiser advice

I know how to do a leak down test, i just have never performed one. What is the easiest way to tell when each cylinder is at TDC? Should i do all the cylinders or just the ones running the lowest?

 

[mkast]

Re: mercruiser advice

I know how to do a leak down test, i just have never performed one. What is the easiest way to tell when each cylinder is at TDC? Should i do all the cylinders or just the ones running the lowest?

Do you have the tester?
The manual will tell you what cylinder is at tdc in the valve adjusting section.
You only have to so the cylinders that are less than 140-160 psi.

 

[01SeaRayBR]

Re: mercruiser advice

That would be all of them haha. I do not have a tester, but i plan on picking one up in the next day or two. I will take a look at the manual.

 

[01SeaRayBR]

Re: mercruiser advice

Any other advice or tips i should do or check while im out?

 

[mkast]

Re: mercruiser advice

i should do or check while im out?

Yeah, find out who is going to pay the national debt, and make sure the compressor is working.

 

[Don S]

Re: mercruiser advice

You don't need a leakdown test on that cylinder or any of them. The oil in the cylinders told the story. you don't have a ring problem you have a valve problem. Even if you do a leakdown test, all it's going to tell you is you will need to pull the head.
Just pull the head, you probably have a tuleped valve on the 0 psi cylinder.
I would also bet your compression tester is way off. Those engines are normally in the 150 to 170 range, and I can't the other cylinders dropping that low in such a short time (2000 boat)

 

[01SeaRayBR]

Re: mercruiser advice

Do you think i should pull the heads while the motor is still in the boat, or just snatch the whole thing outa there?

 

[81 Checkmate]

Re: mercruiser advice

How did you do your compresion check?

just snatch the whole thing outa there?
That to me would all depend on how much money and how much working in the boat space i have.

Could be just needs a valve job on the heads. Heck its only 10 yrs old, must have been rode hard and put away wet.

 

[Don S]

Re: mercruiser advice

or just snatch the whole thing outa there?

If I have jobs at the shop that needs the head/s pulled, I always pull the engine. But I also have a hoist at hand for doing that.
It's just so much easier, faster, and cleaner to work on the engine out of the boat than in it.

 

[01SeaRayBR]

Re: mercruiser advice

I pulled all the plugs, disconnected the distributor, turned the safety switch on so the fuel pump wouldn't run the whole time, opened the throttle wide open, hooked up tester and turned over the motor a good four revolutions. Same procedure when adding oil to the cylinders for wet test. I just purchased the compression tool, do you think its faulty? Unfortunately I don't have a houst or even a big tree in my yard ;( looks like she will be staying in there for at least the intake and head removal.

 

[dingdongs]

Re: mercruiser advice

could always prove tester on a car engine but the heads will have to come off.manifolds are heavy so work safely and if you can take any photos along the way they always are a good reference.your gauge can tell the difference between 62 and 120 so will assume all is well.a manual will be a good investment too.

 

[01SeaRayBR]

Re: mercruiser advice

Yea i thought taking photos every step of the way would be a good idea. I downloaded the manual from adults section yesterday. wish me luck. Thanks for all the help everyone. I will keep yall posted.

 

[01SeaRayBR]

Re: mercruiser advice

Bad news, pulled the head for the side with the cylinder that had 0 psi, piston looks like it has melted some. O boy, long block here i come. Would you guys go with a 5.7 or a 6.2? The 6.2 is $400 dollars more and i have to send my crank out of my old 6.2 to rapido so they can use it to make a 377 or 383 if its 30 over. What do you guys think? Pros? Cons?

 

[Lyle29464]

Re: mercruiser advice

I would find out WHY it happened. A long block will not fix it. See what caused this and budget that into your next move.