1998 Ski Nautique Engine Tag Missing

[AZDave]

The new guy, second post already asking for your help. I did an introduction thread here if you're curious what this noob was asking before.

I brought this boat home this morning and not sure why I didn't pay attention but there isn't an engine tag on this. I'm guessing it's a PLP or PCM? I'm not sure. I'm not too worried if it's 260HP or 285/290HP either one of those will suit my needs. I do however need to service this thing and I will need to do it myself. So impeller size, oil capacity, timing, etc.

If anyone has input I would appreciate it. I would like to put this on the water but I honestly don't know when it's been serviced. I did have it on a hose and started but I would rather just do a good maintenance on the thing and then put it through a good summer.







Thanks in advance.

Dave

[gary s]

If your lucky the engine decal might also be on the starter locating plate - here is a picture that may help you find it. Here is a link to a 1998 manual which supposedly covers all engines,it's located on the header of this page under manuals/brochures https://www.planetnautique.com/Corre...T-40Manual.pdf Use a quality oil filter of your choice along with a good oil with ZDDP usually >1000ppm for flat tappet engines. Use a genuine Sherwood 9959K Impeller

[NautiqueJeff]

Interesting. I never knew that was a possible location for an engine tag. Good to know!

[gun-driver]

3 things you can check to figure out which model engine you have.

1) check the transmission... BW 1:1 or PCM 1.23:1

2) which way does it turn... Righty or Lefty

3) Horse power... check the ends of the heads looking for 3 raised slashes = GT40 heads = 285 HP if no slashes standard heads 260 HP

[AZDave]

Thanks Gary and Gun-driver for helping out the new guy. I did notice the impellers are all the same after more research so I ordered a Sherwood name brand for that. I don't know if the one in it is good or bad but I would rather know. If the current one looks good, I'll have a spare. I see some of the motors take 6 qts of oil and others 4 qts so that's the kind of info I need. Wouldn't mind the bigger HP but either one is fine with me. I'll try and get out there this morning before it's 110 degrees out to check out the markings you all pointed out. Would be nice to just know what I have when I need things for it. It's an older boat so I'll probably find the info handy.

[Jonny Quest]

Well it’s clearly a Ford, so it’s a PLP or PLD (as it's not a GT40). Per the Model Specifications spreadsheet, the engine options for 1998 Ski Nautique were 260 HP (PLD) or 285 HP (PLP). The other 2 engine options were the GT40 and the GM based Apex. I believe that the 1.23:1 transmission was the only option, so that makes it a standard rotation.

As gun driver said, look at the ends on the heads for the telltale 3 raised marks indicating GT40 head. What is the prop diameter and pitch?

JQ

[AZDave]

I haven't had a chance to check the starter plate. I'll be changing the oil when tonight after the sun goes down, way too hot today. I took the boat out for the fist time two evenings ago and it did well. Has a flat spot when accelerating at a certain spot when the throttle is pushed pretty far. I can duplicate the issue so I'm hoping it's just a dirty jet or something. I'll look into it later as I get more time on this boat.

I do want to do the maintenance though so I'll be doing an oil change, tranny fluid, and impeller tonight. That should give me a little sense of security. The wife and I took Monday off to hit the lake with the kids for hopefully a full day of fun.

Here's a shot at the back of the heads, if those fins are the three fins you all are refering to then it looks like it's the PLP model. I'll double check if I can get to that starter plate and see if there's a engine tag but for now I'll assume it's the PLP and go off those specs for now.

[Jonny Quest]

Yup. GT40 heads. Looks like a PLP carby engine.