1987 OMC 1.8L Seadrive

[spies]

Hi all,<br /><br />I am purchasing a boat with two of the engines described above. I know they were only made for one year - so I am wondering if there is anyone out here who has had experience with these motors, and could tell me what to look out for? <br /><br />I am getting this boat really cheap - so I don't mind investing a few $$ in it. So far, I know that the flywheels will turn freely with the spark plugs out - and are very difficult to turn with them in. I plan to do a compression test before purchase, since I cannot get a sea trial.

 

[Dhadley]

Re: 1987 OMC 1.8L Seadrive

The small bore V4's were made from 1985 to 1987 (3 years). The good thing about Sea Drives is that if they lasted this long, they're probably OK. The biggest killer was when the boat company installed them too low and they would injest water. If they haven't done it by now, they probably wont.

 

[muskrat]

Re: 1987 OMC 1.8L Seadrive

junk & hard to parts for..

 

[surlyjoe]

Re: 1987 OMC 1.8L Seadrive

OUCH! muskrat... do you speak from experience?

 

[Solittle]

Re: 1987 OMC 1.8L Seadrive

Well I got a pair of 1987 1.6 L V4 SeaDrives sittin on the back of my 23' CC. I have had this rig for 12 years and love it. I have had zero problems with the SeaDrive units and the powerheads are pretty much the same as the Johnny/Rudes. If you get this rig and plan on doing your own work I strongly recommend that you get the OMC shop and parts manual.<br /><br />I have had no problem getting parts or service.<br /><br />Post back if you get it.

 

[spies]

Re: 1987 OMC 1.8L Seadrive

Wow - what a great response - Thank you! I guess there are widely disparaging opinions, and some facts as well. These are 1.8 L motors, only made in 1987. These engines are mounted pretty high on the transom - So I hope the water ingestion problem will not arise. The boat is a 1987 Pro-Line 25 Walkaround - it has been sitting for a few years on the trailer - I am paying $4500 for it. The hull is in great shape - just needs bottom paint and a buffing. The 'twins' only have 271 hours on them, and as I said in my previous post, both flywheels turn smoothly when the plugs are out. Bought a compression gauge today to check all cylinders. I did get hold of a Seloc Evinrude/Johnson Book, hoping that there are similarities, but if y'all recommend the service manual, I can get that for about 100 bucks. The engines show almost no corrosion, and all parts look clean and move smoothly. Just the usual birdnests and bee hives everywhere. I figure for this price I can afford to invest some bucks in the boat, and it will certainly sell for quite a bit more if I get tired of working on it - Heck - BoatUS asked me how I could be paying so little for it!! I posted a thread in the Pro-Line forum, but there are crickets chirping in there.<br /><br />I appreciate all opinions, and disparaging remarks - Muskrat - DO you speak from experience?

 

[Solittle]

Re: 1987 OMC 1.8L Seadrive

These engines do have a reputation for ingesting water as Dhadley points out. That is due, I think, to ham handling of the throttle while coming off of plane. If you abruptly chop the throttle the stern wave will rush towards the transom and can wash over the engine. The way to avoid this is to kiss the throttle before the wave hits the engine. This takes a tad of planning. The stern will rise up and no harm is done. At least this is the way I do it.<br /><br />Go for the $100 bucks on the manual. By the way there are two manuals depending on whether you have hydraulic steering or not.

 

[Dhadley]

Re: 1987 OMC 1.8L Seadrive

The water injestion was largely due to the motors being mounted too low. Pro Line was one that it was common on but not on every boat. Again, I would think that if they are OK now, they'll be OK. It doesn't take long. <br /><br />Just to expand on that, sometimes the Sea Drives were mounted as high as the boat shape or rubrail would allow but the AV plate was still too low. OMC didn't do a good job of policing that. They did however replace a lot of powerheads under warranty. (With that kind of logic it really makes one wonder why they aren't around anymore)<br /><br />It might not hurt to look at the powerhead and see if it's been upgraded to a 2.0 liter powerhead. Wouldn't surprise me. The tab on the top of the head gasket will tell. Its either straight across or has a U shaped cut out.<br /><br />I'm anxious to hear from Muskrat too.

 

[spies]

Re: 1987 OMC 1.8L Seadrive

Thanks so much again. Hopefully, my photo will come through: <br /><br />

<br /><br />I plan to check the compression on these motors and check the powerheads for upgrades this afternoon - and I will post the results, if anyone is interested. By the photo would you say that the engines are mounted too low?

 

[Dhadley]

Re: 1987 OMC 1.8L Seadrive

It's hard to tell about height from that angle. Let's hope the antiventilation plates (commonly called cavitation plate) is up at least a couple inches from being even with the hull right in front of it when the plates are parallel.

 

[spies]

Re: 1987 OMC 1.8L Seadrive

Got the boat this week, much to the dismay of a lot of people at the Marina where it is sitting. ;> The price was right - $4500. I have the original parts catalog and service manual - both for hydraulic steering 'cause that's what it has - and on top of that I got hold of the option parts guide, all on eBay.<br /><br />I plan to paint the bottom while it is still on the trailer, drop the lower units and service them (clean out old gear oil, replace the water pumps, and check all internal parts), Buff the gelcoat and make repairs to any damage (there is ner nothing to do in that respect). Then I will put the lower units back on and put 'er in the water to work on the powerheads. All hydraulic systems are working fine, with no leaks.<br /><br />The parts catalog for the engines says it has a 'Low Compression Head gasket' - I got around 20 PSI on all cylinders just spinning the flywheels by hand, which was rather difficult to do. Anyone know about this? I know I should check compression with a fresh battery, but that is the initial result. I want to clean the pistons and cylinders anyway, and put new head gaskets on. I also have 8 carburetor rebuild kits on order, and new thermostats. Suggestions? I figure for what I paid, I can invest about $4,000 more in this project, and it will still be worth it.