93 Echelon running on 6 cylinders

[amarfanhar]

Oh %$*&, Bad news....

After rebuilding a carborator, putting in all new spark plugs and distributor cap. The engine was still running rough maxing out at 3800rpm and 33mph while skiing. We did a compression test and here was the verdict...

#2-4, #6-8 pistons 140-150 psi

#5 piston 75 psi

#1 piston dead 0 psi

I need to rebuild my 350 merc carborated or buy a new engine it only had 530 hours 90 of them are mine. Any sugestions? Should I switch it to a fuel injection engine? Should I look to swap it for a "stroker" 383 and move it from 265hp to 400hp? My mechanic is quoting 4-5k for a standard rebuild and his labor. He wants to take a month to get it done and I have a few trips already scheduled in August. Any thoughts?

He recomended I run it through the end of this season (which is short here in Utah). He said that it shouldn't cause any more damage. He'd give me a winter discount if I can wait.

Edited July 21, 2010 by amarfanhar

[99response]

You can usually do a brand new longblock w/ vortec heads for under $3k doing it yourself. A rebuild will be cheaper assuming the block you have is still good.

If you can move to vortec heads you will get that thing up to 300 hp pretty easily. Much easier than doing an EFI conversion.

I'd take a look at Michiganmotorz.com for your options in terms of reman, new longblock, etc.

-Chris

[Michigan boarder]

Before going down that road, could it be a valve issue allowing poor compression? Pulling and redoing the heads is quick and cheap, versus the swap/rebuild.

[amarfanhar]

Before going down that road, could it be a valve issue allowing poor compression? Pulling and redoing the heads is quick and cheap, versus the swap/rebuild.

You were right!! The heads and valves were the issue found on a leak down test. They are going to swap them out for an aftermarket aluminum head kit which will increase the airflow and power a little without the cost of a full rebuild or a 383 conversion.

Any recomendations on an aftermarket head kit for my 1993 350 merc carborated?

[TrickyNicky]

You were right!! The heads and valves were the issue found on a leak down test. They are going to swap them out for an aftermarket aluminum head kit which will increase the airflow and power a little without the cost of a full rebuild or a 383 conversion.

Any recomendations on an aftermarket head kit for my 1993 350 merc carborated?

Wow, send Mb some thanks for that one. Maybe a 24-pack whiel your at it!

This is exactly why

[Michigan boarder]

You were right!! The heads and valves were the issue found on a leak down test. They are going to swap them out for an aftermarket aluminum head kit which will increase the airflow and power a little without the cost of a full rebuild or a 383 conversion.

Any recomendations on an aftermarket head kit for my 1993 350 merc carborated?

Beautiful!! Do you have to change jetting or anything, or just the heads? Woodski, what's your recommendation?

Wow, send Mb some thanks for that one. Maybe a 24-pack whiel your at it!

This is exactly why

Nah, it's a group effort. The mechanic would have found that anyway, I just provided a glimmer of hope until he did. But the crew does, in fact, rule!

[amarfanhar]

I just got a quote back from the mechanic. To do a stock head gasket and valve job he quoted $1581. To do an aftermarket head and valve job to jump my horesepower up from 265hp to 330hp it would be $3113 (twice as much). Do you think the extra power is worth the extra $1500? He said i should have a noticible power increase by doing the aftermarket kit.

Again I have 500 hours on the engine. I just installed new skins from Chee and I hope to keep the boat at least another 5 years.

What do you think crew should I go for more power?

Edited July 26, 2010 by amarfanhar

[Michigan boarder]

I just got a quote back from the mechanic. To do a stock head gasket and valve job he quoted $1581. To do an aftermarket head and valve job to jump my horesepower up from 265hp to 330hp it would be $3113 (twice as much). Do you think the extra power is worth the extra $1500? He said i should have a noticible power increase by doing the aftermarket kit.

Again I have 500 hours on the engine. I just installed new skins from Chee and I hope to keep the boat at least another 5 years.

What do you think crew should I go for more power?

Well, I'd say if all you do is board, then no. If you barefoot, then yes. If you haven't barefooted, then you gotta try it.

Also, shold you be worried about something on the bottom end going (weak link) with a fresh top end? Maybe stick with the stock heads unless you do a rebuild on the rest? Just something to think about, I'm sure a more qualified person than me can answer that.

[amarfanhar]

Well, I'd say if all you do is board, then no. If you barefoot, then yes. If you haven't barefooted, then you gotta try it.

Also, shold you be worried about something on the bottom end going (weak link) with a fresh top end? Maybe stick with the stock heads unless you do a rebuild on the rest? Just something to think about, I'm sure a more qualified person than me can answer that.

I'm mostly a die hard skier. I use the boat a little for surfing when it's choppy and we can't ski and I'm thinking about investing in a wakeboard. But if I opt for the power upgrade (which I think I will) I'm going to start footin.

I asked the mechanic about using my older bottom end with this new powerful top end and he didn't think there would be a problem. I thought the same thing. I think I'm going with the power. Now I just have to figure out how to pay for it.

[martinarcher]

^^ That's pretty good advice right there. If your happy with the power your boat had then I would save the $1500 and go with a normal head job. If your hardcore into slalom or barefooting.....then I have a fever and the only prescription is...MORE POWER.

Glad to hear it's not a bottom end issue! Oh yeah and you guys are right....

[Woodski]

To aid you decision, can you go ski with someone that has a 330 hp (Monsoon) boat and focus on the power level to see if that is worth the $1,500 to you? Personally, I am very happy with the power upgrade, but that is just me. I slalom and barefoot. Also, the aluminum weight savings will make an improvement in the wake at shorter line length's as the pair will be 50# lighter than cast iron. The existing exhaust manifolds will then be your limiter for unleashing all the potential power that is available.

You won't have to rejet the carb, a carburetor is a "dumb" device, so it simply mixes the fuel with whatever the airflow through the carb is, so it will keep pretty much the same air/fuel mixture. Some minor tuning could be required based on swirl or port flow characteristics. One other key element, if you go with aluminum heads, make sure you add a zinc anode as a sacrificial probe in the system. Somewhere in the manifold will work just fine. Also, a cylinder head change will probably be to a D shaped exhaust port shape, so you will need to match the exhaust manifold to the cylinder head. There should be adequate material to do it and you match using the gasket as a guide and grind with a die grinder. 500 hours is no issue, I have over 700 hours on the upgrade alone.

[JDubya]

An extra $1500 would be too rich for my blood. Just coudn't justify the added benefit given how well these engines/boats perform stock.

I would save the $1500 personally. You can reprop to gain the necessary speed to barefoot if you want to try it. I can do a helluva lot with that extra $1500.

[99response]

He's fighting altitude IIRC...

[JDubya]

He's fighting altitude IIRC...

Excellent point, that does change things a bit....still think a prop might be a better solution than a $1500 price jump. But it does change the equation.

edit:fat finger typing

Edited July 27, 2010 by Ramman17

[jk13]

If you can fund it, do it for sure.

My brother just put new heads on his 351 and took his HP from 240-300ish and WOW what a difference. His brother-in-law foots all the time and he loves it. Also, my brother primarily slaloms and yanking his 250lbs out of the water on one ski is a helluva lot quicker and smoother. Mine will be done in a few seasons when the list above it gets crossed off.

Three things you can never have too much of:

1) Money.

2) Horsepower.

3) Watts.

I was going to add time, but if what you are doing at that moment sucks, you can certainly have too much of that.

[soft2]

An extra $1500 would be too rich for my blood. Just coudn't justify the added benefit given how well these engines/boats perform stock.

I would save the $1500 personally. You can reprop to gain the necessary speed to barefoot if you want to try it. I can do a helluva lot with that extra $1500.

I could foot at 42 mph behind my 93 Echelon with stock mercruiser and original 3-blade prop, which was 4mph faster than I liked to go. I weigh 180 and our lake is at 1,000ft. Never felt like I needed any more power or speed. I tried a 4-blade and it went faster but sucked for barefooting because it created way more prop wash and a harder pull in the slalom course. One thing I always liked about the echelon, and Malibus in general was the great barefoot wakes with low turbulence compared to almost any other inboard.

Having said all that, I'd go for the power upgrade just because it will be more fun to drive!

[amarfanhar]

FYI...

I'm going with the power upgrade. Money doesn't grow on trees but I'll get more. I'm now excited to get it out on the water with a little more juice!!! I think I have been running on 6 cylinders for the entire season it will be a shock to have it up to stock specs not only an extra 75 horses.

Thanks for the advice all

[Woodski]

Good point on altitude, what is the altitude of the lakes you spend time on? At 5000 ft, you will have 83% of the sea level power rating, at 6000' it will drop to 80%. That might also help you make a decision.

[amarfanhar]

I picked up the boat yesterday!!! The engine looked pretty with the performance edelbrock aluminum intake manifold and roller cam shaft. We fired it up and the timing was off so the adjusted the timing and got it running well at the shop. I would say the engine has 30% more power than it did stock.

So, I took her out for a ski last night. Wahoo!!!!!!!!!! It fired right up with a great deep rumble. I took it her out quickly before we loaded the car driver after launch... I needed to see what she could do. At 5000 feet elevation, it got up to 30mph in about 4 seconds 40mph in 6 seconds. The top speed was 43mph with 4 180lbs people in the boat at 4800rpm. She was running great. She has some serious extra torque and power(at least 30% more power).

Some small complaints that require some tuneing.

- The engine was running ritch. Gas fumes were by the driver seat and observer seat.

- More boat vibration than usual at high speed, could be the prop.

- It stuttered and almost backfired with a WOT upon starting a skier. Carb adustment?

Check out my restoration and the new engine pic's https://www.google.com/accounts/ServiceLogin?passive=true&go=true&continue=http%3A%2F%2Fpicasaweb.google.com%2Flh%2FviewAlbum%3Funame%3Dcowleygardner%26aid%3D5505125612906202753&service=lh2

Edited August 14, 2010 by amarfanhar

[wienrdog]

The stutter & backfire on wot startup sounds like a lean condition & is typically an accelerator pump adjustment. Had to do that a few times on my previous boat.

Can't help you much on the others.

[amarfanhar]

The stutter & backfire on wot startup sounds like a lean condition & is typically an accelerator pump adjustment. Had to do that a few times on my previous boat.

Can't help you much on the others.

How do you adjust the accelerator pump? I had a leakey crankshaft gasket (oil leak) and replaced it and a timing issue whick I think we fixed yesterday. I'm taking it back to the lake this morning but would love to adjust the accelerator pump.

[martinarcher]

The stutter & backfire on wot startup sounds like a lean condition & is typically an accelerator pump adjustment. Had to do that a few times on my previous boat.

Can't help you much on the others.

I'll backup the lean condition hypothesis. Ours did the same lean backfire under hard acceleration to WOT when the fuel pump was giving up.

[OLDGUY]

Thats a great looking boat.

[amarfanhar]

I found the accelorator pump and adjusted it for more fuel flow. I'll let you know if it solved the problem.

[martinarcher]

If your carb is a Holley this should help....