1988 Marlin Ski Magnum overhaul

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

I'd like GPS and will look into it once everything is done.

As to the life vests, I agree, the boys weren't scheduled to go on the test run, but I didn't have the help watching them I had planned on.

Throttle cable bracket is flexing and moving. I was able to see 4500 WOT today with no tuning changes, just making sure not to overstress the bracket. Speedometer said 39.

I was taking on more water than expected and found a screw I left out of the stern trim plate eek: and a drain petcock that was leaking at the back of my starboard manifold.

I know my prop shaft packing needs another strip of packing and adjustment, but I went with the floor in yesterday and again today.

We stalled in the middle of the lake while sitting at idle and couldn't get the engine to restart. When I got home I pulled the plugs and found water in # 6 and 8 but none of the plugs had the steame cleaned look. Fearing I had done mechanical damage I ran a compression test on that bank and found

#2 155
#4 155
#6 155
#8 175 (this was the cylinder with the most water)

I pulled the starboard manifold and retested it for leaks with acetone and found none. the riser is new and I tested it also and found no leaks, but the gasket surface of the manifold was a little off, so I dressed it down and put a new gasket on it and reinstalled it.

Oil level was good and oil was clear and clean so I cranked the engine plugs out to get rid of the water and squirted some oil in the cylinders and cranked again.

Plugs are back in, wires are back on and battery is getting a full charge back on it and I am calling it a night.

Tomorrow I'll try and fire it up and see if I have the problem licked.

I am very disappointed, but hopefully I got through this without any damage and everything will be okay.

 

[Bob_VT]

Re: 1988 Marlin Ski Magnum overhaul

Hmmmm a 50-50 test run. Glad it hit the water. The kids looked happy nut not really buckled up

I would have guessed a gasket..... your getting closer!

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

I'm going to change the other side tomorrow even though there was no water in the cylinders. The gaskets were the cheapo type and I didn't pay attention to the difference of the quicksilver brand and the cheapos. I thought I had a bad manifold, but retested with acetone and looked inside while it was off with a flashlight and saw no sign of seepage or fluid loss.

Kids enjoyed the run up the river and back and got to see some neat stuff. 2 guys playing in kyaks had caught a 4 foot copperhead and my youngest wanted to bring it home. I suspect we avoided trouble yesterday as I didn't let the engine idle much at all after we got away from the ramp.

I let a friend drive and he slowed to an idle and sat there a few minutes and then the boat stalled. Glad the boys weren't there today. Luckily we were within sight of a ranp and some nice folks gave us a quick tow, and another boat took my pal over to the right marina about 6 miles up the lake and he brought back the 4 runner and trailer. dragging the boat around a tied up TWRA boat and onto the trailer was uneventful and the boat loaded just fine with the winch strap. Even with a dead boat we were able to retrieve in under 5 minutes.

Hearing your guess of a gasket makes me feel better. These marine exhausts are a new animal to me, having wrenched on cars a bit and my only prior boat was a 175 Mercury outboard in a 19 foot Checkmate (With I had kept that for high speed runs!)

I got my 2 part foam in the mail yesterday. I was almost going to forego it, but the water leaks today and the noise makes me glad I ordered it. I know the interior will absorb some noise once I get it done, but my boat is loud! Thankfully, it sounds good.

Oh well, I never expected the first run to be perfect, I just hope I didn't do any damage to my engine. I think I am okay though and got enough running in to have started the break in.

Now I need to asses the flaws and develop a plan for addressing them.

Looks like the upholstery can wait a bit longer.

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

After dealing with the leaking manifold last weekend, I found that my ignition module (inside the old prestolite BIO distributor) was going bad by checking it with an OHM Meter. Got a replacement in Thursday and put it in this morning, reinstalled the distributor and fired it right up. Set the timing and after adding a strip of rope seal to the stuffing box, rewiring the electric choke and checking everything with a multimeter, it was off to the lake.

Got back on the water today and it seems I have beaten two minor problems, identified two more and managed to limp in with my engine missing.

I could push down on plug wires and the engine would smooth out and pick up RMP, but I also got some mild shocks, so I picked up some new plug wires.

My shaft log is leaking at the hull at a pretty good clip and my water pump is dripping some water too. Nothing that the bilge pump couldn't handle, but an annoyance, so I'll pull those parts and try and get them right.

Now the boat needs to dry out and I am going to remove the driver's seat (again) and pour my foam in the next few days. Hopefully next weekend I'll give her another run with these few problems ironed out.

Ran it with the engine cover off today and when you open the throttle all the way up it sounds like the SOB is going to fly! Saw 4400 at WOT again so I think I am going to have some fine tuning to do.

My trailer needs some adjustments, but launching and loading was super smooth. I think it took us under a minute to launch and maybe twice as long to load. Figuring out where to stop with the trailer has made a big difference.

As soon as I feel the boat is reliable and all the bugs are worked out, I'm going to start on finishing the interior. Stay tuned for more pictures

 

[proshadetree]

Re: 1988 Marlin Ski Magnum overhaul

Doc has shots for bugs man.Oh wait you mean the boat my bad.Kill them one at a time and soon theyll be all gone.Good looking ride man.

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

Snuck out to the Cumberland river tonight for a quick test run. New wires definitely helped. Top RPM was 4500. I bought a hand held Garmin 72 GPS and got a true speed measurement. Running upstream I hit 40 miles per hour and running downstream I hit what I considered to be an astonishing 45 miles per hour. Speedometer stopped at 39 both ways so it is close to true water speed as I figure on calm flat water I'd be running about 42.

My distributor turned during the run and I had to limp in -again.

Pulled all plugs and they looked fine then reset the timing and tightened it back down.

Lettering is on the sides of the boat now and foam is going in Thursday or this weekend depending on work, weather and such.

The brightest part of the trip was that my boat is no longer leaking water at all. My shaft log was a little tight and I loosened it to get a small drip and will have to tweak the adjustment, but it is close now.

Soon I will start back on the interior work and the stereo install, but I have a project going tearing out a bomb shelter that takes. . . well took up about half my basement space. If you need busted up concrete I have a whole bunch (about 60 feet of 7 foot wall) come and get it. with my basement under demolition, my tools are stacked and tarped so I have a shop renovation to complete before I can get to my saws and woodworking tools.

I am frustrated with the continuing engine issues and while they are all seemingly minor, it is getting me down. Hopefully the next trip will have these problems finally resolved. I want to take my kids out, but the boat has to be reliable. I hope that I am getting there. Perhaps this weekend I can get a good run in without any issues. Is that too much to hope for?

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

Well I spun a bearing or something that killed my oil pressure the last time out.

UGH!

So tonight I got my wrenches out and in 2 1/2 hours I had the engine out. Will update as soon as I get a handle on what is going on.

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

Engine is at the machinist for tear down and evaluation. I should know something next week.

I thought about pulling the pan and checking the main bearings, but decided to just let him look it over as I don't want an argument if it is a warranty issue.

Been having evil thoughts like building a 383 with high ratio roller rockers, higher compression, a better intake and a slightly hotter cam. I like the feeling and sound of power, but I keep coming back to the reality that it is a ski boat hull and even if I add another hundred horsepower it will never have the top end of an outboard with half the horsepower.

Oh crap! I just realized I need another boat! LOL

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

Spun main bearings with a suspected leak of gas into the oil is the diagnosis. Hope to have the engine back in early August.

In the meantime I have gotten some upholstery work finished and added flotation foam to the boat. I managed to move my bunk boards and winch post back to make the trailer a little less tongue heavu, but it is still way heavier than I had hoped. At least the transom is now properly supported and the prop has much more clearance. I am going to try and get a little more cosmetic stuff done and the floors glassed between now and the motor re installation.

All of this adds new deadlines and goals, so I am now hoping to put the boat back on the water by Labor day weekend which will make the overhaul a one year project.

Maybe I can post a few progress photos later on tonight.

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

Well here is the interior work to date. The seat back has the stripe over the wrapped cushion. Everything else was stitched. I am probably going to take it back apart and redo it but for now it gives you a flavor of what I am doing.

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

Foaming the floor doesn't lend itself to lots of pictures, but just in case you want to see glued in plugs

Oh and I have been tearing out concrete walls in my basement so just to give you an idea until the basement is reorganized and photo worthy I included most of the block I removed with a maul, a chisel and a sledge hammer. I didn't include the full yard of sand that was poured in between the walls.

 

[Rickairmedic]

Re: 1988 Marlin Ski Magnum overhaul

Jmark looking good I like the wraparound bench on the passenger side .


Rick

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

Thanks, but I decided I didn't like the rear seat back cushion and spent an hour pulling staples than about another hour sewing in the stripe and making a pattern for the sides and sewing it all together. Looks a lot better now. I'll update the photo tonight.

Next project is to clean things up and put some glass on the deck. The alternative is to work on my side panels, but the weather here has been a little cooler than usual and working outside isn't uncomfortable, so I think I better take advantage of that.

Working wood in the shop is definitely more pleasant than laying glass when it heats back up!

 

[Rickairmedic]

Re: 1988 Marlin Ski Magnum overhaul

Jmark I dont know how much wall you have left to remove but Harbor Freight sells a 1" SDS rotary hammer drill for less than $100.00 that will make quicker work of that wall .


Rick

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

It is all out, just reorganizing all my crap.

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

Well I didn't like the seatback, so I spent a couple hours redoing it last night. It was easier than expected, my recommendation to anyone wanting to do their own upholstery is to get a very good staple gun!

 

[Rickairmedic]

Re: 1988 Marlin Ski Magnum overhaul

Much better looks like a pro did them . I have an air stapler so hopefully I will be ok there .

Rick

 

[lowkee]

Re: 1988 Marlin Ski Magnum overhaul

Wow, much better looking seat after the redo. The one from earlier looked a little 'bubba-ie', but I just didn't have the heart to say it .. especially since it likely looked better than what mine will, hehe.

What are you using to sew them? Commercial or Home machine? I just can't get myself to pay for a commercial machine and the homes ones just look chinsy to me. Luckily I have a ways to go before I am stressing about it. Wait, that probably isn't a good thing.. I need to work faster!

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

I am using a Janome home machine. I run it on a fairly slow setting with a medium wide stitch width. The bigest thing I have found is to use a good sharp needle and plan on how to control the excess fabric to be able to feed it through without hanging up. I have rolled up excess fabric on each side and used a strip of painters tape to hold the rolls shut. Also holding pieces together and stitching through the painters tape gives me a nice straight seam. Afterwards the tape pulls off and I trim the excess behind the seam down to a 1/4 inch.

The stripes are easy enough to do, butI elected not to do one on the seat bottom simply because it will get the most stress and also getting the stripe to line up looked like it might be a bit difficult with the shape of the seat, so i elected not to include the stripe there. Next I have to do the side panels, but I am waffling between using the panels I have cut already or redoing them in a slightly different manner.

I'm heading to Canada for 9 days on Friday so no more progress photos til after that, but my engine will be ready when I get back, so I hope to be on the water again by the 9th or 10th of August with the interior at least 80% done. I'll still have the mismatched blue engine cover unless I come up with a brilliant alternative than can be done in a day.

 

[J. Mark]

Re: 1988 Marlin Ski Magnum overhaul

Well my engine is back in the boat awaiting final assembly but I have been sidetracked with a different sort of "boat" Thought I'd share a picture.

351C 4V with 4 speed toploader and 456 gears-halfway thought about throwing the engine in the boat when I hit 6000 RPM in 4th gear last night