1987 Thundercraft 18' Ski Boat

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Were your out of water adjustments to the shift interrupter switch adequate or did you have to tweak it more in the water?

Did you reference any manuals or other info in order to figure out how to adjust it? I think I may have the exact same problem with my 4.3L OMC Cobra (stutter on shift to forward, kind of tough to find neutral).

Also, can you describe a little more where it was on the engine? I unfortunately don't have a fully removable dog house, so it's a lot tougher for me to get into my engine compartment.

Hi Sean,

I'm glad you brought this up. NO, the adjustments where NOT adequate. Once you get the prop in the water the shift points will change (ie, the moment the drive starts to go in gear compared to your controls up front). I would say you can get the adjustments close, at best, on land and finish them up once you get to the water. I had to do just slight adjustments, and it's perfect now.

I used information from this site: http://www.hastings.org/~stuart/cobra/ . I was able to figure out the function of everything once I had it apart.. At that point, it was just getting the timing right. I didn't adjust the cable that goes trough the transom to the drive.. I just adjusted the point at which the front controls pull enough to engauge the SIS.

The switch is on the top port side of the engine. If you are facing the engine while standing inside the boat, it is the top left side directly above the valve cover. There are 3 cables going to this one switch, so it is pretty easy to track down. Hope this helps!

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Thanks for the kind words everyone!!

Decided to finish up the other side today:

Before:

And After:

Enough cosmetic stuff for now.. I'm pulling the drive off next week to replace the bellows, grease the u-joints, and replace the gimble bearing (if needed). If anyone has any pictures or tips of the process, I would appreciate it!

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Hmmm... I sure don't post much in the winter, do I?

Well.. I went and did a BAD THING. I pulled the drive, replaced all the belows, greased everything up... and did not take a single picture. Shame shame shame on me.

Pulling the drive for anyone that stumbles across this thread:

Very Easy. Very. Do not be intimidated by this for one second. I set the drive down until it was just about to touch the skeg and put a piece of plywood under it. Unbolted the hydraulic rams, and loosened the 6 bolts that hold the drive on. I had to use a couple of pry bars (GENTLY!!) to seperate the drive.

Once it was out, I could easily pick it up and move it by myself.. I'm not sure on the weight, but I would guess under 150 pounds. I had a friend help align the splines when I put it back in, but I found it was very do-able for a single person to pull it.

Pulled the pivot plate off with 2 allen heads, and it was a cake walk to work on from that point.

I'll find out next weekend if the water issue is resolved. I filled the bildge with water after I finished to see if I could see any leaking out. None. Zip. Zero. Nadda. I REALLY hope that this issue is resolved..

Other little stuff I've done and didn't take pictures like an idiot? I moved the hydraulic fluid cooler from the back of the engine to up on the transom. I can now easily reach the plug for winterization, and I gave myself enough hose to bypass it if it ever starts to leak. I had to go back and use a few screws to hold all of the new upholstery in place. I still want to pull the side panels and replace the carpet this year. I changed the oil (no freaking oil drain plug, so I had to suck it out the dip-stick!!!), and all of the filters and fluids are ready to go for the start of the year.

Next time I do any work on the boat, I won't be an idiot and I'll remember to take pictures!

 

[coolguy982]

Re: 1987 Thundercraft 18' Ski Boat

Great work on the boat, and thanks for the informative posts and pictures.

I recently acquired (first-time boat owner) a 1987 Thundercraft Citation with a 4.3L engine and OMC Cobra outdrive. It's a lot like yours, but has a bench seat in the back with a full engine compartment and is blue instead of red. Luckily my upholstery has been taken care of and doesn't need replacing!

The boat was sitting in the water for quite a while and I faced the same oxidization problems on the hull and outdrive. I got it buffed out of the hull for the most part (except the very bottom), but the outdrive still needs repainted. I see that you spray painted your Cobra outdrive. Could you provide a bit more detail about how you did this? What type of spray paint did you use? Has it held up well? What all did you cover with masking tape when painting it?

Thanks!

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Great work on the boat, and thanks for the informative posts and pictures.

I recently acquired (first-time boat owner) a 1987 Thundercraft Citation with a 4.3L engine and OMC Cobra outdrive. It's a lot like yours, but has a bench seat in the back with a full engine compartment and is blue instead of red. Luckily my upholstery has been taken care of and doesn't need replacing!

The boat was sitting in the water for quite a while and I faced the same oxidization problems on the hull and outdrive. I got it buffed out of the hull for the most part (except the very bottom), but the outdrive still needs repainted. I see that you spray painted your Cobra outdrive. Could you provide a bit more detail about how you did this? What type of spray paint did you use? Has it held up well? What all did you cover with masking tape when painting it?

Thanks!

Hi Coolguy,

I really didn't do anything fancy with the paint. I just taped off the emblems, the hyraulics rams, around the drive on the transom, and anywhere else I didn't want paint. Then I just shot it with some rattle can rustolium.

Worked really well for about 1 season. Then it started to flake a little. I've noticed that places that were bare before I shot the rattle can seem to have held up well, and places that still had factory paint came off with more chunks of the factory paint.

If I had to do it again, I'll probably strip the thing down to bare metal and go after it with better paint. This worked fine for a while, but it looks like hell again.. I'm not sure a quick rattle can job is the best solution!

I would love to see pictures of your boat and get some more information on it.. You just don't seem to see a lot of these old thundercraft boats out there anymore!

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Okay.. Sun was out, was finally a nice day about 50 degrees.. I decided to get a little work done on the boat again!!

Have I mentioned before that I need a shop? Because I need a shop. This working outside constantly is for the birds..

The first major area that I decide to attack was the doghouse. I put new upholstery on it last season, and it worked just fine. However, it looked like complete crap as far as I was concerned. I was never happy with the wrinkles and lines, and finally gave up and just pulled it around until it looked alright from the front. This was the result:

Ugh.. I know, I know.. Like I said, it looked alright from the front but really did not look good at all from any other angle. So I ripped it apart and started over:

I still couldn't get the vinyl to stick how I wanted. I always had these terrible lines, and I wanted to keep the black/grey them going... So I got this far, and decided to tear it apart.. AGAIN. Ugh.

This time I decided that if I wasn't able to get the seams to look how I wanted, I would just hide them. Off to the lumber yard I went.. and away I walked with some teak wood. Pound per pound, I think this stuff might be more expensive than gold. Wow. But, it started to give me the look that I wanted:

Still need the cup holders:

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

There we go. That looks a little more gooder.

Of course, then you get to sand and tear the entire thing back apart for stain... Argh.

And then re-assemble everything...

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Now I figured it was time to deal with the sides.. Here is what I was working with again for reference:

So I started ripping the boat apart again.. Thank god this time I was able to reach most of the bolts that are tucked in under the cap. This allowed me to save 99% of the factory mounting hardware!!

Worked on the little side cushions at the rear first:

 

[coolguy982]

Re: 1987 Thundercraft 18' Ski Boat

Thanks for the info. Did you paint right over the bolt/screw heads as well as the prop?

I'll take some more pics soon and PM them to you or start a new thread to avoid stealing your thread, but I've attached one here of the boat in the water. Right now it's in the shop getting the prop shaft seals replaced (had water getting into the gear oil).

Scott

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Then I moved on to the big stuff. This was actually really easy compared to the damn dog house and seats. If everything had these simple lines, I would have finished this last year!!

I know some folks probably cringe when they see things done like this.. But this foam is EXPENSIVE!! So, I just repaired a couple of areas that had bad foam with some new foam. Basically, I just filled spots in so it would look good once the vinyl was stretched across it:

Yup.

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Hey it may not look like much.. But there is a lot of damn work in this little picture!!!

Now I just have to put it all back in.... Hey where did that bolt go?

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Darn good thing I finished it when I did.. Because we were out on the water the next day!!

I think I'll do the carpet yet this season. Maybe Santa will bring me some nice center seats, since I don't think that I'm going to try and re-do those nightmares...

Boat ran like a champ. I'm thinking a nice new stainless prop may help with the hole shot though. I'm kind of a big guy to pull up on 1 ski, so a little better hole shot would be a good thing. Other than that, we had a great day out on the lake!!

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Thanks for the info. Did you paint right over the bolt/screw heads as well as the prop?

I'll take some more pics soon and PM them to you or start a new thread to avoid stealing your thread, but I've attached one here of the boat in the water. Right now it's in the shop getting the prop shaft seals replaced (had water getting into the gear oil).

Scott

Hi Scott,

Yeah I just painted right over everything. I've had the out-drive off since and had no issue with the paint making bolts/nuts difficult to remove. Like I say, it looked good for about 1 season but really fell apart after that.

Your boat looks great! I love the lines of these old Thundercrafts.. I think the glass just makes them look mean. I've always liked how they sit in the water too. Let me know when you get that thread up, I'd love to see more!

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

My 5th of July project!

Decided we wanted to be able to listen to a little music while out on the water. I didn't want to deal with CDs skipping, so I picked up a CD player that also had an ipod in jack.

After searching around the boat for the best place possible, I landed on the jockey (glove) box. In here, the player would be almost 100% safe from wet towls/people, and is completely out of the weather. I did a lot of measuring before I started to cut. I found that on the side the CD player could sit flush and still have enough room behind the box to not be a concern:

The CD deck:

Tucked away nice and safe:

And the hard part.. Where the hell to put the speakers. I considered putting them in my freshly reupholstered sides.. But I couldn't bring myself to cutting that area out again just for a set of speakers. Instead, I used a pair of 6x9 speakers in factory made speaker boxes. I'm actually happy with the location. You can hear the stereo very well from inside the boat, but it shouldn't car AS BAD as some of the other options.. Especially to the front of the boat.

Also set the timing over the weekend, but didn't take any pictures. Boat is still running like a champ even after all these years!

 

[SeanT]

Re: 1987 Thundercraft 18' Ski Boat

Nice stuff! I agonize over speaker placement as well. Convenience vs. invasiveness...

 

[coolguy982]

Re: 1987 Thundercraft 18' Ski Boat

Good work on the radio install. My Thundercraft has a radio mounted in the glove box as well, but it's on the bottom of the box rather than in the side so it takes up a lot of space. I like how you mounted it in the side. My radio needs replacing so I might do the same thing.

What did you do to support the backside of the radio? One concern I had with a digital radio is that if I don't wire it to the battery at all times it will lose the radio memory presets. Do you have that problem, or do you only use it to play iPod music?

Oh, and I finally got around to starting a thread about my Thundercraft! I have pics of the radio and speaker locations.

 

[TNbrave]

Re: 1987 Thundercraft 18' Ski Boat

I have a 1987 thundercraft ski boat,but i use it for fishing.When i put it in cold water its hard to start,it starts good in Warm water,would temp have something to do with it...its a 4.0 L motor.

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

Good work on the radio install. My Thundercraft has a radio mounted in the glove box as well, but it's on the bottom of the box rather than in the side so it takes up a lot of space. I like how you mounted it in the side. My radio needs replacing so I might do the same thing.

What did you do to support the backside of the radio? One concern I had with a digital radio is that if I don't wire it to the battery at all times it will lose the radio memory presets. Do you have that problem, or do you only use it to play iPod music?

Oh, and I finally got around to starting a thread about my Thundercraft! I have pics of the radio and speaker locations.

It is a tight fit there, but it does fit. I tried to put it so it would be at the back of the glove box rather than the side, but I couldn't find a spot that would have enough room. This ended up working just fine though.

The Dual CD deck came with a large metal frame that I used to support the player. I removed the deck from the frame, and got it in the spot with an extremely snug fit. I then bent the tabs in place to hold it. I cut the hole snug, and with the metal frame in place it isn't going anywhere. Time may wear it loose, but I seriously doubt that it will move an inch.

Where we boat, we don't even get cell service. lol. It is a large resevoir in the middle of no-where Idaho. I don't have to worry about radio stations or anything like that. I wired both the dedicated power source and the switched source to the toggle. It is kind of pain for the CD player to index the music when you shut it down. After a while of turning it on and off when we were on the dock and what not, I finally just left the toggle up all the time. That way I didn't have to worry about it searching my ipod every time I wanted to listen to music.

I'll check out the thread!

 

[md-lucky]

Re: 1987 Thundercraft 18' Ski Boat

I have a 1987 thundercraft ski boat,but i use it for fishing.When i put it in cold water its hard to start,it starts good in Warm water,would temp have something to do with it...its a 4.0 L motor.

Thats kind of an interesting issue.. I would post that question in the engine section.

These are fairly old carbuerated engines.. I know that I usually have to pump my throttle twice and then try to start it. I also keep it in neutral and bring the RPMs up to about 1100 right after it starts, and I let it warm up for a minute before I take off.

Once it has been running for a while and is up to temp it runs fine. It is just that intial start after sitting for a week that sometimes is a little difficult. I've never had a "hard start" condition, but it will crank for closer to 2-3 seconds when cold rather than the instant "touch the key and fire" when it is warm.

 

[calinip]

Re: 1987 Thundercraft 18' Ski Boat

NIIICE WORK!!!!! i love it..seeing your pics and progress just motivated me to do the same!