1990 suspra sunsport-what to inspect/check first

[Konakev]

I have just recently purchased 1990 supra sunsport classic.
The motor starts and runs. Sounds ok but likes to start with choke on at first...Although, I dont trust anybody when it comes to boat motors. I like to do the maintenance and service myself if I can. This boat comes with a 454 PCM motor with about 850hrs on it and my questions are as follows

1) what problems should I be most concerned with this motor?
2) maintenance recommendations? Ie: known issues with specific part wear.
3) best place to find parts for the motor.

I can tell I will have a long relationship with this boat assuming everything in the motor checks out and I look foreward to keeping the forum updated with how it goes. I'll be posting pics of before and after once I get it all cleaned up
Thanks in advance

[Mischief IV]

Congrats on the purchase. New members can’t post pics until they have a few more posts to prevent spam. Posting pics here sucks bigly so use a third party website like Imgur.com or use the Tapatalk app.

1. I think not winterizing the motor correctly is the number one issue people experience with inboard boats. Search for a good thread on here or YouTube to learn more.

2. Change the oil and the impeller regularly.

3. Visit SkiDim.com Calling them works best, have great tech support.

[Konakev]

Congrats on the purchase. New members can’t post pics until they have a few more posts to prevent spam. Posting pics here sucks bigly so use a third party website like Imgur.com or use the Tapatalk app.

1. I think not winterizing the motor correctly is the number one issue people experience with inboard boats. Search for a good thread on here or YouTube to learn more.

2. Change the oil and the impeller regularly.

3. Visit SkiDim.com Calling them works best, have great tech support.

Awesome thanks for the heads up! I've been trying to research YouTube university trying to find exactly how to replace the impeller (I'm not having any luck) since I cant view pics in here it's hard to see the photos of what other ppl are doing for a fake lake and impeller change...

[Konakev]

Anyone have a part# for the impeller kit for the 454 pcm engine? Engine code is PLM-WR-L10

[crystal waters]

Anyone have a part# for the impeller kit for the 454 pcm engine? Engine code is PLM-WR-L10

As Mischief IV said - - -
Call Skiers Discount Marine
Aka Ski Dim
They are your best source for parts - know their stuff!
They will also give you technical advice on how to change your impeller.
Use them !

[Konakev]

As Mischief IV said - - -
Call Skiers Discount Marine
Aka Ski Dim
They are your best source for parts - know their stuff!
They will also give you technical advice on how to change your impeller.
Use them !Awesome will do!

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[hoop46]

Highly reccomend a silicon impeller. Pretty sure my backup rubber one will dryrot before the silicon one will give up.

[Konakev]

Highly reccomend a silicon impeller. Pretty sure my backup rubber one will dryrot before the silicon one will give up.Where can I find those?

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[Konakev]

Well, glad this is the first thing I checked...https://uploads.tapatalk-cdn.com/20200312/ba93a8cabaa4f6ef9daaba7bbed3f2c5.jpg

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[Konakev]

Also, when I was removing, one of the bolts snapped on the sherwood pump. It didnt take much to snap, I dont think its seized it's probably just a severely corroded/rusted bolt. Will try to remove later today at work. https://uploads.tapatalk-cdn.com/20200312/b05e50d4f79aff8a0851e988338ef1f4.jpg

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[michael hunter]

It should have been a stainless steel bolt the housing is brass corrosion should not have been a factor. Use a little heat and vice grips to get the old bolt out.

[Konakev]

So, got the boat out on the water today. A couple concerns....
1) boat vibrates quite a bit, It could be bc I'm not used to the older style boats, but how much it "too much" and what could be caused? (Its only while underway)
2) upon inspecting the engine compartment i did find a little bit of water coming in from the drive shaft that goes thru the hull... (worn bearing? Possible cause for vibration?) Nothing too serious other than I wouldn't feel comfortable leaving boat in water overnight.
3) boat seemed to run very hot (see photo) and oil pressure seems high... after about 20 mins of runtime. Not sure why it's so high... possible thermostat bad? Not opening? Any help is appreciated. https://uploads.tapatalk-cdn.com/20200322/4c40b80a309e5faac500e9d12f05d401.jpg

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[Konakev]

Update, replaced thermostat. Pulled old one and placed in boiling water. Never opened. I'm assuming its bad... replaced with new. (180*) hopefully it cools down, now my oil pressure in another thing.

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[NorCalPR]

Lookup how to align the propshaft. It should be done every couple of years. It takes about 30 mins with some feeler gauges. If its really out of whack, maybe an hour tops...

Also, dumb question but is the prop dine and dent free? The smallest ding can make a difference.

As for the leaks, small drips while underway are normal. When stopped it should not drip. I can't remember off the top of my head but somewhere around 1 drip every 5 to 10 seconds is normal. It's better to have more drips than less, as too little cooling on the packing glands will score the shaft and will require propshaft replacement.

The packing around the propshaft needs to be cooled by water when running. You can tighten the nut to slow the leakage. If its tight but youre still getting too much water in, replace the packing.

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[Konakev]

Lookup how to align the propshaft. It should be done every couple of years. It takes about 30 mins with some feeler gauges. If its really out of whack, maybe an hour tops...

Also, dumb question but is the prop dine and dent free? The smallest ding can make a difference.

As for the leaks, small drips while underway are normal. When stopped it should not drip. I can't remember off the top of my head but somewhere around 1 drip every 5 to 10 seconds is normal. It's better to have more drips than less, as too little cooling on the packing glands will score the shaft and will require propshaft replacement.

The packing around the propshaft needs to be cooled by water when running. You can tighten the nut to slow the leakage. If its tight but youre still getting too much water in, replace the packing.

Sent from my SM-G920V using TapatalkGood info thankyou. I'll look into it. I've never had to align the shaft before. Maybe that's my problem...as for the nut and letting in too much water. I'll look into that too..

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[Konakev]

Next on the to-do list
The temperature. Is this a normal temp for the motor to be at? At what point should I be worried? I put a 180 degree thermostat in there. But not sure if that's good or not. It climbs slowly up to about that area. And stays.
2nd photo is the gelcoat after 1full day of buffing and waxing. Not perfect but way better than it used to be.https://uploads.tapatalk-cdn.com/20200328/50f3baee922b92b37e66677e688bc375.jpghttps://uploads.tapatalk-cdn.com/20200328/bb5dba988297f5d964c447cb5184fd8c.jpg

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[hoop46]

My Comp stays at 160 in the summer time. If the water is cooler it will sit around 150.

[scottschmitt]

Video on aligning shaft: https://www.youtube.com/watch?v=5UqniaiggKA. The vibration is either from this or from the prop being banged up. It doesn't take much of a ding on the prop to make things vibrate.

Blog description of how to fix leaking at the stuffing box: https://marinehowto.com/re-packing-a-traditional-stuffing-box/. These boats are designed to leak at the stuffing box. There is a wax string that helps seal the stuffing box. It dries out and needs replaced. Skidim has the string or you could replace with Goretex: https://www.skidim.com/prodinfo.asp?number=GFO316X24. The stuffing box needs adjusted every now and again.

On temp, check your hoses and see if any are soft and might be collapsing under low pressure. That impeller looked pretty rough. Maybe the hoses also look a bit rough. Hopefully you don't have chunks of the impeller stuck somewhere. Maybe a 160 thermostat will help.

That gel coat wax is looking sharp!

[Konakev]

Video on aligning shaft: https://www.youtube.com/watch?v=5UqniaiggKA. The vibration is either from this or from the prop being banged up. It doesn't take much of a ding on the prop to make things vibrate.

Blog description of how to fix leaking at the stuffing box: https://marinehowto.com/re-packing-a-traditional-stuffing-box/. These boats are designed to leak at the stuffing box. There is a wax string that helps seal the stuffing box. It dries out and needs replaced. Skidim has the string or you could replace with Goretex: https://www.skidim.com/prodinfo.asp?number=GFO316X24. The stuffing box needs adjusted every now and again.

On temp, check your hoses and see if any are soft and might be collapsing under low pressure. That impeller looked pretty rough. Maybe the hoses also look a bit rough. Hopefully you don't have chunks of the impeller stuck somewhere. Maybe a 160 thermostat will help.

That gel coat wax is looking sharp!Thanks. I worked hard on the gel coat. I'll look up those threads thanks

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