scottchapin
07-25-2011, 04:22 PM
So about 8 weeks ago I got a 1988 Supra Mariah for $4000. It had some problems but seemed like a pretty good deal and I am happy to have an inboard after 4 boats with IOs and outboards. The motor ran well and the transmission seemed to shift well so I figured I couldn’t go too wrong for the price. I knew the boat needed some work and was prepared to put in the labor if not the money. Everything was going to have to be done on the low cost side. Eight weeks later the boat works well and we’re enjoying it. I figure I’ve probably got another $500 into it and about 100 hours of playing with it. I’ll post what I did in case someone else needs low cost options. These forums have been extremely helpful so thanks to everyone for the great posts. I won’t put in the things I learned how to do from previous posts but I’ll try to explain things I learned along the way. Supra purists may not want to read this since it is definitely a budget boat post.
I’ve also included the cheat sheet I made for the most commonly needed parts and settings.
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First up was power washing everything. The motor went from yuck to nice in a few minutes and the trailer wheels turned out to be chrome. The PO kept putting grease in the hubs and it had just sprayed all over the wheels so you literally couldn’t tell what was under the grease.
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The floor had some soft spots but the stringers and motor mounts feel solid so I didn’t want to replace them. I’m hoping to get some years out of it before that’s mandatory (plus we live in a really dry place and the boat is kept on the trailer where it can dry out between uses). So first up was tearing out the old carpet that looked really bad and putting in a false floor and new carpet. I just jigsawed together 3/8 outdoor plywood, covered it in Lowe’s outdoor carpet and screwed it down. Of course during this I had to create new pieces for the ones that were totally rotted. The two sections over the drive line needed replacing and creating bracing for them was an interesting experiment in engineering. The cover around the pylon was rotted too so I included that in the false floor. I chose to remove the ski pole as we only wakeboard and the pole was only good for creating bruises (any old skiers can use the tow eyes on the transom right). For the engine cover base I wrapped it in the same carpet and used SS staples. A PO had rebuilt this base with treated 2x10 and used a really ingenious way of holding it together with the odd angles. He used SS door hinges on the inside of the odd front angles. Sorry I didn’t take a picture before covering it. After reading about the trouble people have had with this, the hinges actually seem brilliant.
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Next came getting the motor in shape. New plugs, points, condenser, cap, oil, trans fluid, clean the spark arrester, set the timing, aligned the motor, adjusted the carburetor (and sprayed a lot of cleaner through it -I’ll get to a rebuild over next winter), adjusted the electric choke, and replaced the drive shaft packing (thanks for the great write up on how to do this and the tip on using dental type picks!).
--------------------
I ran into the problem of the starter motor staying engaged when the key had been turned off (common it seems). First I replaced the starter solenoid but that didn’t fix it. After reading how low amperage and bad grounds caused this I cleaned all the connections but that still didn’t fix it. Then in taking the ground wires off again I realized the ends of the ground cables were the problem. They were loose on the wire and just twisted right off. No wonder I had a bad ground. So I cleaned up the cable ends and the cable itself then crimped the ends on real well and taped them up. That fixed the problem. Now it starts right up and is reliable. It still runs rough until very warm but I think the carburetor is the culprit. Also during this phase I put a cool 8 ball handle on the throttle lever so my 15 son would think the boat is cool too (Pepboys).
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On a water test run the boat would heat up too much (190) while idling but would cool off as soon as we started going so I thought the impeller was bad. When I took it apart the impeller still looked good but I put the new one in anyway (NAPA). After putting in a new impeller the same problem was happening. Turned out to be the EZ flush water system. I’ve got the type where the garden hose connects to a fitting mounted to the transom and the T’s into the fresh water intake hose. The plug that you put in when the hose is not connected was missing and the system was letting the impeller draw air through the line. When I got a plug and stopped the impeller from drawing air in through the fitting, and thus through the T in the fresh water intake hose, the problem went right away. I think the T is supposed to have a spring loaded valve to prevent this but apparently it needs replacing so it’s on the list for someday.
---------------
The seats looked ok (dirty white) but on further inspection three of them needed re-building as the wood was totally rotted out. I just removed the staples with a screw driver and pliers then used the rotted wood as templates to make new ones from 3/8 outdoor plywood. A couple were rotted enough to where using them as templates was more like guessing but it all worked out. Then just stapled the covers back on with SS staples. The ski locker cover and engine cover needed to have the wood replaced that the hinges mount to also. This was a very poor design with cheap materials on Supras part way back when. New wood (oak and then treated) did the trick. Once I got all the seats done I went to clean them but they turned out like crap. Magic eraser, Simple green, upholstery cleaner, nothing worked. A friend suggested painting them with vinyl spray paint as he had done it before. I decided to go for it instead of spending the money on new upholstery. 17 cans ($100) of spray paint later and it looks great, well way better than before. This paint is awesome, doesn’t come off, very easy to use, durable, inexpensive (relatively), and hides a lot. Only trouble is the paint turned out much darker than the cap would suggest. I used the medium gray which turned out more like dark gray to me (and a touch greenish). The vinyl had a few small tears in it so I taped them with vinyl tape before spraying. You can tell they were taped but it sure looks better then having tears. I used Duplicolor paint from the auto parts store. I would highly recommend this if your upholstery is ok but looks like crap due to age, dirt, etc.
-----------
The ski locker (rear bench type) Supra put in was made of thin plastic that had cracked over the years. This was a really BAD design. I wanted an easy repair and I’m not great with fiberglass so I just used the existing plastic tub and coated it with a layer of fiberglass mat. First cut it to strips you can work with then roll on the resin with a disposable roller, then the glass, then roll on more resin. I put a layer around the lip and covered the underside completely. A little sanding and spray paint and good to go for another 20 years. Probably $15 total at Lowe’s.
I’ve also included the cheat sheet I made for the most commonly needed parts and settings.
------------
First up was power washing everything. The motor went from yuck to nice in a few minutes and the trailer wheels turned out to be chrome. The PO kept putting grease in the hubs and it had just sprayed all over the wheels so you literally couldn’t tell what was under the grease.
-----------------
The floor had some soft spots but the stringers and motor mounts feel solid so I didn’t want to replace them. I’m hoping to get some years out of it before that’s mandatory (plus we live in a really dry place and the boat is kept on the trailer where it can dry out between uses). So first up was tearing out the old carpet that looked really bad and putting in a false floor and new carpet. I just jigsawed together 3/8 outdoor plywood, covered it in Lowe’s outdoor carpet and screwed it down. Of course during this I had to create new pieces for the ones that were totally rotted. The two sections over the drive line needed replacing and creating bracing for them was an interesting experiment in engineering. The cover around the pylon was rotted too so I included that in the false floor. I chose to remove the ski pole as we only wakeboard and the pole was only good for creating bruises (any old skiers can use the tow eyes on the transom right). For the engine cover base I wrapped it in the same carpet and used SS staples. A PO had rebuilt this base with treated 2x10 and used a really ingenious way of holding it together with the odd angles. He used SS door hinges on the inside of the odd front angles. Sorry I didn’t take a picture before covering it. After reading about the trouble people have had with this, the hinges actually seem brilliant.
----------------
Next came getting the motor in shape. New plugs, points, condenser, cap, oil, trans fluid, clean the spark arrester, set the timing, aligned the motor, adjusted the carburetor (and sprayed a lot of cleaner through it -I’ll get to a rebuild over next winter), adjusted the electric choke, and replaced the drive shaft packing (thanks for the great write up on how to do this and the tip on using dental type picks!).
--------------------
I ran into the problem of the starter motor staying engaged when the key had been turned off (common it seems). First I replaced the starter solenoid but that didn’t fix it. After reading how low amperage and bad grounds caused this I cleaned all the connections but that still didn’t fix it. Then in taking the ground wires off again I realized the ends of the ground cables were the problem. They were loose on the wire and just twisted right off. No wonder I had a bad ground. So I cleaned up the cable ends and the cable itself then crimped the ends on real well and taped them up. That fixed the problem. Now it starts right up and is reliable. It still runs rough until very warm but I think the carburetor is the culprit. Also during this phase I put a cool 8 ball handle on the throttle lever so my 15 son would think the boat is cool too (Pepboys).
------------
On a water test run the boat would heat up too much (190) while idling but would cool off as soon as we started going so I thought the impeller was bad. When I took it apart the impeller still looked good but I put the new one in anyway (NAPA). After putting in a new impeller the same problem was happening. Turned out to be the EZ flush water system. I’ve got the type where the garden hose connects to a fitting mounted to the transom and the T’s into the fresh water intake hose. The plug that you put in when the hose is not connected was missing and the system was letting the impeller draw air through the line. When I got a plug and stopped the impeller from drawing air in through the fitting, and thus through the T in the fresh water intake hose, the problem went right away. I think the T is supposed to have a spring loaded valve to prevent this but apparently it needs replacing so it’s on the list for someday.
---------------
The seats looked ok (dirty white) but on further inspection three of them needed re-building as the wood was totally rotted out. I just removed the staples with a screw driver and pliers then used the rotted wood as templates to make new ones from 3/8 outdoor plywood. A couple were rotted enough to where using them as templates was more like guessing but it all worked out. Then just stapled the covers back on with SS staples. The ski locker cover and engine cover needed to have the wood replaced that the hinges mount to also. This was a very poor design with cheap materials on Supras part way back when. New wood (oak and then treated) did the trick. Once I got all the seats done I went to clean them but they turned out like crap. Magic eraser, Simple green, upholstery cleaner, nothing worked. A friend suggested painting them with vinyl spray paint as he had done it before. I decided to go for it instead of spending the money on new upholstery. 17 cans ($100) of spray paint later and it looks great, well way better than before. This paint is awesome, doesn’t come off, very easy to use, durable, inexpensive (relatively), and hides a lot. Only trouble is the paint turned out much darker than the cap would suggest. I used the medium gray which turned out more like dark gray to me (and a touch greenish). The vinyl had a few small tears in it so I taped them with vinyl tape before spraying. You can tell they were taped but it sure looks better then having tears. I used Duplicolor paint from the auto parts store. I would highly recommend this if your upholstery is ok but looks like crap due to age, dirt, etc.
-----------
The ski locker (rear bench type) Supra put in was made of thin plastic that had cracked over the years. This was a really BAD design. I wanted an easy repair and I’m not great with fiberglass so I just used the existing plastic tub and coated it with a layer of fiberglass mat. First cut it to strips you can work with then roll on the resin with a disposable roller, then the glass, then roll on more resin. I put a layer around the lip and covered the underside completely. A little sanding and spray paint and good to go for another 20 years. Probably $15 total at Lowe’s.