help with omc sterndrive

[nismo]

I am a first time boat owner and bought a used boat, the boat is a 19' aeroglass carisma 188, it has a 5.0 liter chevy 305 inboard motor, and an omc sterndrive lower unit. I know very little about boats, but am learning very fast as i repair this one. The question that i have is how do i find out what model of lower unit i have? All it has on it is "omc sterndrive", the prop will not spin by use of the motor, but will spin by hand. I was told it needed a shear pin however i have also been told that the omc sterndrives don't have shear pins in them.I see the ball gear spin and it makes an awful racket until the lower unit is lowered, at which time it quiets down, but the prop still will not spin. If anyone is familiar with these types of drives any information in helping me locate the problem and what i may need to replace would be very helpful. I have been looking through the parts list for omc sterndrives and see several listings for "cobra" and "800" as well as "400" and see that some take a drive shaft and ball gear setup, but i have no idea what drive shaft i would need to order. I have looked all over the lower unit as well as the motor for any model numbers and found a few on the motor itself but none on the lower unit. I thank you all in advance for any help or leads you may be able to give me, other than "junk the omc and buy a mercruiser" lol as i have already been told that by several people.

thanks,
Nismo

Forgot to mention it is a 1985 model boat, i am assuming the motor year is the same though i can not be sure.

 

[gst95dsm]

Re: help with omc sterndrive

Being an 85 it could be a stringer or a Cobra. If there is a large boot around the drive then I would say it's an 800 stringer drive. If the drive is mounted to the transom then it's a cobra drive. Sorry I do not know what is causing your problem though as I too am just learning about the OMC stuff.

 

[xltier]

Re: help with omc sterndrive

the stringer and cobra look nothing alike.the cobra sorta resembles a merc.the stringer could have a half moon type gear that raises and lowers it on the port side.a pic would be great.

 

[Bondo]

Re: help with omc sterndrive

I see the ball gear spin and it makes an awful racket until the lower unit is lowered, at which time it quiets down, but the prop still will not spin.

Ayuh,.... You bought a 800 Stringer drive,...... Good Luck, you're gonna Need it.....

 

[fendersfender]

Re: help with omc sterndrive

yep...800 series.....is it cooling? if its not cooling its probably the water pump shaft thats broken,,,,if it is cooling, it could be the lower unit, heck, it could be anything...i hope your mechanically inclined and have a service manual, or....a HUGE wallet....these drives were outdated when they made them...they are problamatic and high maintenance...believe me, i have twin 800 series on my boat...but if it is pumping water, its either the lower unit or something with the shifting mechanism....the lower units are fairly reliable on these, its the upper units and tilt mechanisms that are a pain.....good luck, get a manual

 

[nismo]

Re: help with omc sterndrive

Thank you all so much for your help. "yep...800 series.....is it cooling? if its not cooling its probably the water pump shaft thats broken" this actually makes me wonder now and seems a viable reason. I noticed yesterday after the motor had been running for a short time with the muffs on and running cold water threw the lower unit as i was instructed to do when running it out of the water, that the temp gauge went up to about 240 degrees, now i'm new to boats and i'm learning as i go as i stated before, but i have worked on cars for many years, and know a bit about motors especially since this is a chevy small block, and i know it should definatly not run that hot since i was running water through it from my garden hose. So that will be the route i will take first in my project, unfortionatly i do not have a manual, but will be picking one up. I will also take some pictures this evening for further help identifying the correct drive. thank you all again for your help, i am starting to rebuild my faith in the kindness of people and the willingness to help out others.

 

[Fishermark]

Re: help with omc sterndrive

I can't help too much except to say a couple of things...

1. Yes, that outdrive / prop does have a shear pin. I know because I sheared one before on an old stringer drive.

I see the ball gear spin and it makes an awful racket until the lower unit is lowered, at which time it quiets down,

2. From what I understand, you should never run the engine with the outdrive all the way up as it will greatly wear out the ball gears.

 

[chiefalen]

Re: help with omc sterndrive

guys that drive has a key.it might be the water pump shaft.they strip the splines sometimes.first thing first get a manual.now is the best time to shoot yourself in the head cause your in for one wild ride.i bought mine for the trailer and the guy threw in the boat stupid me.you'll have to pull the drive.maybe just the lower end to get to the water pump.when you pull the water pump you'll see if its the shaft not to bad if all you'll need to do is a shaft and a water pump.i bet its fried.buy the whole kit with the plastick housing.good luck post what happens.

 

[nismo]

Re: help with omc sterndrive

ok, so here are some pictures of the lower unit, i hope they help to identify exactly what it is. Again i thank everyone for all of their help so far and in the future. Chiefalen, I too bought mine for the trailer and the boat came with it. I paid $500 for the trailer, well sorta, the boat belonged to my father in law who bought it from a friend of his, he ran it for one season until it stopped operating. he doesn't know much about it at all. He has basically told me i could have the boat instead of paying him the $500, so it was really a free boat. Can't go wrong with free! I will pull the bottom end of the lower unit and check the water pump shaft, unless these pictures show something different and ya'll have other suggestions.

 

[WizeOne]

Re: help with omc sterndrive

I did not have time to read the whole thread. Got to get to a dinner arraingment.

What I did read causes me to say "DO NOT RUN THE ENGINE WITH THE OUTDRIVE IN THE UP POSITION". You will wear out the ball gear and blow the bearings in the intermediate housing as well as the upper outdrive housing.

Never run with the outdrive any more than 15% +-, and that only to get you out of a shallow water situation.

I know you have other issues but ultimately, the above, is of utmost importance. Also, don't let everyone snow you on the OMC. Short of salt water usage, that unit blows away Mercs in very many respects.

Any thing you have has ways they want to be used and or maintained. Do it right with that mechanical shift OMC and you will have a very good time boating.

You will never have to listen to things like upper shift cables, lower shift cable, gimbal, gimbal bearings, alignments, u-joints, yokes, etc, ad nauseum.

Oh, did I forget to mention that you do not have to change your impellar every year?

Ok guys, start slinging it!

 

[chiefalen]

Re: help with omc sterndrive

my boat didn't run for eight years.took it home put in a battery checked the oil and 3 or 4 tries it started i couldn't believe it.anyway you have to check the boot make sure it has no cracks.if it has one hole replace it.ebay is the place to get most of the parts you'll need.brp or doug russel marine have it online every year and model #'s to look up part numbers.my boat never let me down yet but i did need to put in a new riser,starter.impeller kit,valve cover,and timing cover alternator,t-stat again today.i like the way the drive turns way farther than a merc.and the drive comes up farther than a merc.in the right hands this setup cant' be beat.however getting parts is a b-yatch.when you get to know it maybe you'll love hate it like alot of people.now everything i had to replace you have to check also.never run it up ever.always have water running to the drive when you start it even for 5 seconds or you will toast your impleller.the tilt housing must be opened and cleaned out and packed with greese.you must greese the zerks on the outdrive.and don't forget the one on the backside half way up it's in a hole.greese the turning gear.keep an eye on the outdrive gear oils all three.keep up posted and we will help u.good luck

 

[bruceb58]

Re: help with omc sterndrive

I can't help too much except to say a couple of things...

1. Yes, that outdrive / prop does have a shear pin. I know because I sheared one before on an old stringer drive.

No, it does not have a shear pin. The older stringers that did not have thru prop exhaust had shear pins.

 

[nismo]

Re: help with omc sterndrive

Thank you chiefalen, so by the pictures that i included is this a stringer 800 or a cobra or something else? Or can you or anyone else tell from the pictures?

 

[bruceb58]

Re: help with omc sterndrive

It is an 800...not a Cobra.

 

[nismo]

Re: help with omc sterndrive

Sweet, thanks soooo much! now the search for parts begins

 

[chiefalen]

Re: help with omc sterndrive

it is a stringer.

 

[NW Redneck]

Re: help with omc sterndrive

I'll back up my fellow white anchor guys WizeOne and Chiefalen, OMC drives ain't as bad as you'll no doubt hear everywhere. I've got a '75 electric shift I resurrected after a 15+yr 'hibernation'. While parts may take a little looking for, a great many can still be found. I've come to like mine, even with it's weak points (ball gears, tilt system). They don't have MORE problems than mercs, just different ones. After working on mine and then my FIL's merc, I feel the OMC is a simpler system. I'm a KISS kinda guy, I'll take take simple if all it means is a little more care with operating and maintenance. IMHO, engine development peaked with the old Ford straight 6's. Efficient? Not realy. But they'll damn near run forever! And the plugs are ALOT easier to change than on my Exploder!

 

[nismo]

Re: help with omc sterndrive

Just an update, i have the bottom end of the lower unit apart. I think i have located the problem, I do have some more checking to do but it got dark on me before i could finish inspecting everything. this is what i have found so far and it may be very good news. Once i got the bottom end apart, i pulled the top barring off of the shaft and was working the shaft back and forth to see how much play it had in it, I noticed the prop was spinning after i pushed the shaft down, so this is what i am thinking is happening: I think the cables are not engaging the rod all the way down which would lock the shaft into drive mode. Does this sound like it makes any since to anyone? Or have i completely lost ya'll on my description? Does this not sound like it could be an adjustment issue? Also i think i found my cooling problem, there was this huge bees nest right in the water inlet channel of the bottom end, it was definatly big enough to block the flow of water. All the barrings look good, seems to be little to no wear on them.

 

[chiefalen]

Re: help with omc sterndrive

your water pump is in the upper gear case easier to work on when u lift the outdrive up.thats where i think the water pump shaft stripped out or the key snapped if snapped key thank your lucky stars.when u have it apart replace the impeller.than your good to go for 3-4 -5 years maybe.maybe you might want to rebuild it totally up to u need the kits though.good luck post here your results well help u if we can

 

[Zero Balance]

Re: help with omc sterndrive

Sweet, now the search for parts begins

To be honest, in your search, I'd consider searching for a reputable OMC mech. He'll likely be old and crusty like mine treating you like you know nothing at first but after you get to know him better he'll likely be you and your boats best friend.

I've had my stringer apart a couple times. The first to have some things checked out before I bought the boat. The second to replace my water pump several years later. Soon again it will be time for ball gears and a new diaphragm. My stringer is 40 years old and runs like the day it came off of the show room floor. They are just different from the norm and that scares most people.

These drives are built like a tank. If it was well taken care of and is in good shape internally it will bring you years of pleasure with your boat. Don't be a skeered of OMC.

pop off the cone at the prop and see if the pin is in there, if not, install one. If it is... Like I say, find a good mech.

Good luck in your endeavors.