1991 Four Winns 4.3 Cobra overheat and now stern drive noise

[Ski Bob]

Overheating and now stern drive chattering on 4.3 cobra stern drive

I have a 1991 Four Winns 200 Horizon with a 4.3 Cobra and Cobra stern drive. I am the original owner and the boat is MINT and has NEVER had engine or drive issues other than a lower shift cable. So, problem is last week at the lake saw temp creeping up to 220. Would not cool by idle so had to shut down. Ten minutes later restart and ran fine. Few hours later putsing along at say 15 MPH in deep water overheat alarm went off at 230 to 240 degrees. Again, would not cool so had to shut down. Waited thirty minutes and restart ran great rest of day including water skiing. So, came home, pulled out thermostat housing and replaced thermostat. At no time was there weeds or any sediment on lower unit. No sediment or obstructions in hoses that I could tell. Anyway, started right up with muffs, water exhausting like normal but I could hear what sounded like hammering push rod, spun bearing or something hammering. Again, idle was perfect but hopped out and lower unit is hammering away inside by the tilt rams to the point I didn?t want my head next to it. Sounds like it wants to fly apart in the lower unit. This was at high idle, say 1500 RPM. I also noticed that temp was again creeping up to say 175 degrees. This thing has for twenty years ran at 165 degrees and I have noticed it has been creeping up about ten degrees but never with a garden hose. So, now I don?t dare lake run this thing because the lower unit sounds like it?s going to burst. Hope it isn?t the engine too but can?t pin down exactly all the hammering due to the stern drive pounding away. It has the exact same pounding whether it is in neutral, forward or reverse. As soon as RPM get over 1000 RPM, it is hammering away in stern drive bad! Any ideas? Thanks, Bob

 

[HT32BSX115]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Overheating and now stern drive chattering on 4.3 cobra stern drive

I have a 1991 Four Winns 200 Horizon with a 4.3 Cobra and Cobra stern drive. I am the original owner and the boat is MINT and has NEVER had engine or drive issues other than a lower shift cable. So, problem is last week at the lake saw temp creeping up to 220. Would not cool by idle so had to shut down. Ten minutes later restart and ran fine. Few hours later putsing along at say 15 MPH in deep water overheat alarm went off at 230 to 240 degrees. Again, would not cool so had to shut down. Waited thirty minutes and restart ran great rest of day including water skiing. So, came home, pulled out thermostat housing and replaced thermostat. At no time was there weeds or any sediment on lower unit. No sediment or obstructions in hoses that I could tell. Anyway, started right up with muffs, water exhausting like normal but I could hear what sounded like hammering push rod, spun bearing or something hammering. Again, idle was perfect but hopped out and lower unit is hammering away inside by the tilt rams to the point I didn’t want my head next to it. Sounds like it wants to fly apart in the lower unit. This was at high idle, say 1500 RPM. I also noticed that temp was again creeping up to say 175 degrees. This thing has for twenty years ran at 165 degrees and I have noticed it has been creeping up about ten degrees but never with a garden hose. So, now I don’t dare lake run this thing because the lower unit sounds like it’s going to burst. Hope it isn’t the engine too but can’t pin down exactly all the hammering due to the stern drive pounding away. It has the exact same pounding whether it is in neutral, forward or reverse. As soon as RPM get over 1000 RPM, it is hammering away in stern drive bad! Any ideas? Thanks, Bob

Howdy,

Welcome Aboard!

A good place to start here would be in the following link.....focus particularly on #1 and put some paragraph breaks in your posts to make it a little easier for all of us to read! http://forums.iboats.com/omc-i-o-in...have-technical-information-diyers-468655.html

Overheating problems are almost ALWAYS raw water pump or raw water related. not as much the thermostat(they do fail though)

If you have had a raw water pump failure in the past and the pump disintegrated, the pieces may be clogging enough down-stream to result in an overheat.

Running it for even a min can be enough to damage or destroy it.

You may have to remove the drive to determine exactly where the "noise" is coming from.

Have you had the drive oil changed recently? And was it changed IAW the OEM OMC manual?

What's the actual model number of the engine (is it original?)





Regards,


Rick

 

[Ski Bob]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Ok, thank you for your responsive post.

Ok, it is original engine and book says it is a 4.3 Cobra (Chevrolet) says so on intake and model in book says 432APRRG1. That said, I was up all night reading the hundreds of posts. A lot of smart folks on here! So, I opened up the lower unit cover (the 3 3/8 bolts and pulled off the impeller housing. IT looks MINT with no issues at all or leaks. By the way, read that these three bolts should be torqued at 108 to 132 ft lbs? I just tightened them down good.

So, then pulled hose from thermostat housing that leasds to the power steering cooler I didn't know I had and water flushes cleanly out the drive. No debris either. Then flushed both manifold hoses as well and again, clean out the drive.

By the way, I DID replace the thermostat because the one in it was original. In fact, everything other than the lower shift cable and shift lever is original. I need to get this thing out more!

By the way, I am going to change out the unit grease because the boat did sit last season due to a car crash and I was out of commission. Trying to get back into things now and turned into the broken boat people!

So, I did all this flushing and now ran the boat with muffs. Ran like a watch! Temp stayed at 170 degrees and went to 175 when I let it run at 2000 RPM. But it DID NOT heat up. Ran boat for 45 minutes!! Of course muffs are muffs and the lake is the lake!

Now, I am going to take your advice and change out the gear lube. So, I was told to use high temp gear lube but will certainly take your advice. Currently using Evinrude/Johnson HPF XR Synthetic Blend recommended by the boat dealer by me. Good fit or no?

Appreciate all the advice from you folks and the other posts are very helpful. Thank you.

PS. I have been kicking around the idea of ditching the ENTIRE OMC stern drive and going with something else. AS it is right now, the shift lever is broken and not safe. The neutral lock lever is broke so I do need to address it. I know I could start a new thread, but my brother in law has a pretty new boat with a Volvo Penta and the darn thing shifts like a car! Mine shifts like a truck! Thanks again. Opinions welcome! Bob

 

[bruceb58]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

By the way, read that these three bolts should be torqued at 108 to 132 ft lbs? I just tightened them down good.

108-132 INCH pounds.

Sounds like you need to pull the drive to investigate your noise issues. How often have you been pulling the drive, changing drive oil, changing u-joint bellows...?

 

[HT32BSX115]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Ok, thank you for your responsive post.

Ok, it is original engine and book says it is a 4.3 Cobra (Chevrolet) says so on intake and model in book says 432APRRG1. That said, I was up all night reading the hundreds of posts. A lot of smart folks on here! So, I opened up the lower unit cover (the 3 3/8 bolts and pulled off the impeller housing. IT looks MINT with no issues at all or leaks. By the way, read that these three bolts should be torqued at 108 to 132 ft lbs? I just tightened them down good.

Howdy Bob,

Um....it's probably 108-132 IN-lbs! I think Ft-lbs would strip them!! And you might have a closer look at the engine model number....

Here's the 1990 and 1991 models from BRP -- Parts Catalogs
432AMLPWS 1990
432APRPWS 1990
434AMLPWS 1990
434APRPWS 1990

432APLRGD 1991
432APRRGD 1991
434APLRGD 1991
434APRRGD 1991

By the way, I am going to change out the unit grease because the boat did sit last season due to a car crash and I was out of commission. Trying to get back into things now and turned into the broken boat people!

Have a look at the manual for replacing the gear lubricant. Be sure to follow the OEM instructions for filling a Dog-clutch Cobra.....do it wrong and you replace the drive.......Boatinfo - OMC 1986-1998 Service Manual

So, I did all this flushing and now ran the boat with muffs. Ran like a watch! Temp stayed at 170 degrees and went to 175 when I let it run at 2000 RPM. But it DID NOT heat up. Ran boat for 45 minutes!! Of course muffs are muffs and the lake is the lake!

You're good if it stays that way! If there's a slight leak in the pump that allows it to suck any air, it will be a problem in the lake.

Now, I am going to take your advice and change out the gear lube. So, I was told to use high temp gear lube but will certainly take your advice. Currently using Evinrude/Johnson HPF XR Synthetic Blend recommended by the boat dealer by me. Good fit or no?

Just about ANY GL-5 gear lubricant will work. most of us like the synthetics too. (Mercury HP, Volvo Syn, E-Rude/Johnson syn, Mobil 1, Amsoil, etc etc...by the way, there IS NO[ASTM or NMMA] Marine spec for gear lubricant)

PS. I have been kicking around the idea of ditching the ENTIRE OMC stern drive and going with something else.

Yes. I did that. removed my OMG 460 King Kobra and replaced it with a MUCH newer Mercruiser 454/Bravo III.

Replacing with a newer Volvo SX is absolutely a great choice too.

I found my engine and drive on Craigslist. I looked for a Volvo for quite some time and never found a suitable combination but found several Mercruiser choices.

You would need to find the entire drive and gimbal mount + flywheel housing and exhaust system (manifolds and risers) for the new engine + shift linkage etc..... A really good way is to find a donor boat with the engine and drive you want. you could even go to a 5.0/5.7L V-8

That way you get all the small parts that would cost a small fortune if you had to obtain them individually.

 

[sea wolf]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

That knocking sound coming from the drive could be u-joints. Could be. Pull the drive & take a look.

If you want to dump the OMC, SEI Sterndrives has a conversion kit for that Cobra. But it will run you about 2k & that's if you don't need a new shifter at the helm.

 

[Ski Bob]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Ok, thank you all very much. Ok, Model number is the 432APRRGD a 1991 4.3 Cobra Chevrolet.

So, I am going to stick with the synthetic oil in the drive it seems? So, Evinrude it is. Going to change it this week before hitting the lake.

Ok, so this may surprise you. I have NEVER pulled the drive off in the 22 years I have owned the boat. It has been pulled three times by two separate dealerships. The first was when I asked for PREVENTITIVE maintenance and ended up having them stretch the lower shift cable, which took to the next season to diagnosis. So, another repair place figured out the stretched cable and fixed it. Then it was bad again so again they pulled the drive to fix it again. I am now noticing a few THUNKS when throttle up after putting it in Forward gear. In the past, a stetched shift cable causes the thing to not be completely into gear until I throttle up, hence forth the thump. Sounds like a rubber mallot striking the transom. So again, I will take it to hopefully a trusted Four Winns dealer. They are hard to come by in Minnesota.

On the gear lube, I change it EVERY FALL when I winterize the boat. I DID NOT change it last year because the boat sat the entire year in a garage due to my car crash. By the way, I never knew I had this power steering cooler so I never "DRAINED" it or anything of the sort. What I always do is remove the hose from the thermostat housing that leads to it and place it as low as I can in the engine cavity, draining it? Is this adequate? I have never done it any other way and nothing has froze so apparently ok? In fact, I beleive this hose from the Stat housing goes into the TOP of the cooler if I am remembering correctly. So, when we pull the screws out of the drive to drain the water, is that draining that cooler? Man, question after question! Mayby I buy another Power Ball ticket and buy the new Four Winns H310 31 footer! Nice.

So, this boat does not have the hours or use exposure of most other 1991 boats. I know time eats up everything so I have to keep that in mind but I have never had ANY drive issues, other than the shift cable and the throttle lever breaking twice.

The throttle lever was replaced in year two and it is broken again now. The safety lift underneath is broke so yes, if you fall against the throttle it WILL go into gear and take off. Yup, better fix it. But, if I ditch the OMC and go to something else, do I have to replace that anyway?

So, to recap. Thanks for all the advice. Going to change gear lube this week again to Evinrude/Johnson synthetic. Then, I am going to lake test it to see if it heats up or makes any drive noise that I heard the one time. I agree, maybe the drive was tilted in just a way that the U-Joints were rattling? Otherwise, it is devine intervention and I won't object to any of that either!

 

[bruceb58]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Sounds like you haven't been maintaining the drive very well. The drive should be pulled every year to check for water in the bellows and for alignment. Your bellows should be changed every 5 years. If your boat actually has 22 years on the original bellows, it would not surprise me if you have water in there. I would pull the drive before I put it in the water again.

 

[HT32BSX115]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Sounds like you haven't been maintaining the drive very well. The drive should be pulled every year to check for water in the bellows and for alignment. Your bellows should be changed every 5 years. If your boat actually has 22 years on the original bellows, it would not surprise me if you have water in there. I would pull the drive before I put it in the water again.

I'm surprised the gimbal bearing, U-joints or even the coupler hasn't failed! That bellows has probably been leaking at least for 5 years or more!!

So, when we pull the screws out of the drive to drain the water, is that draining that cooler?

Which "Screws" on the "Drive" are you referring to?

Depending on the position of the PS cooler, it may drain sufficiently to prevent freeze damage if it hasn't happened......

 

[Gangly]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Your Gimball bearing can make a racket too if it isnt greased up. Grease it through the fitting and see if that eliminates the rattling.

 

[Ski Bob]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

I told you I need a Four Winns repair place in Minnesota. I am mechanically inclined but not to smart on the outdrive! Can you tell?

Ok, the screws I pull on the drive, sorry no book in front of me, there are two vent screws on one side and one on the other. In fact, when I was reading one post, one screw that I am sure I pull every fall had a sticker post that said, "NEVER REMOVE THIS SCREW" Wow. Yup, wondering again. But no book handy, as I am at work. So, I was wondering when this hose is drained, does it not drain this pump? Am I just getting lucky?

So, that said, the cooler sits at a 45 degree angle and the hose I am draining goes to the top of this cooler. The bottom of it has a hose that goes to the outdrive?

As far as doing anything with the bellows or U-joints, I have never done anything! Never knew other than to change drive grease. I need to look up the bellows and U-joints as I know NOTHING about them!

So, if I decide to switch to a new stern drive, should I just wait and pull all this and sell it on craigslist? Wow, such decisions.

Thank you all. You are a very smart bunch. Makes me feel stupid!!! Bob

 

[HT32BSX115]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

I told you I need a Four Winns repair place in Minnesota. I am mechanically inclined but not to smart on the outdrive! Can you tell?

Ok, the screws I pull on the drive, sorry no book in front of me, there are two vent screws on one side and one on the other. In fact, when I was reading one post, one screw that I am sure I pull every fall had a sticker post that said, "NEVER REMOVE THIS SCREW" Wow. Yup, wondering again. But no book handy, as I am at work. So, I was wondering when this hose is drained, does it not drain this pump? Am I just getting lucky?

well, if you DIDN'T remove the "Never-Remove screw" you're money-ahead!!

So, that said, the cooler sits at a 45 degree angle and the hose I am draining goes to the top of this cooler. The bottom of it has a hose that goes to the outdrive?

You maybe dodged that bullet!!

As far as doing anything with the bellows or U-joints, I have never done anything! Never knew other than to change drive grease. I need to look up the bellows and U-joints as I know NOTHING about them!

You'll need an OEM manual for the procedure. It's not all that hard.

So, if I decide to switch to a new stern drive, should I just wait and pull all this and sell it on craigslist? Wow, such decisions.

Thank you all. You are a very smart bunch. Makes me feel stupid!!! Bob

That's what I did. before that I hadn't done much with boats......

I'll speak for myself........Nah......I'm not all that smart......I don't do any of this stuff for a living! but I am a heII of a DIY'er!!

 

[Ski Bob]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

I'm surprised the gimbal bearing, U-joints or even the coupler hasn't failed! That bellows has probably been leaking at least for 5 years or more!!

Which "Screws" on the "Drive" are you referring to?

Depending on the position of the PS cooler, it may drain sufficiently to prevent freeze damage if it hasn't happened......

The screws I was referring to when I winterize are the three on the stern drive pivot housing. I remove the water drain plug on the port side of the drive housing and on the starboard side I remove the vent plug and drain plug. Don't mix the "drain" plug with the drain for the stern drive grease. In other words, there are three identical screws that have a little rubber O-ring on them that I have removed every fall and "momentarily" turn the engine to blow out any water in the pivot housing. It is in the manual. Hopefully I have that correct. By the way, yup, the manual says to remove the hose on the bottom of the power steering cooler I didn't know I had to drain it. Have I been ducking the rock for 22 years? So, this year I will tilt the darn thing or remove the bottom hose! Wow, what an idiot.

 

[Ski Bob]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Sounds like you haven't been maintaining the drive very well. The drive should be pulled every year to check for water in the bellows and for alignment. Your bellows should be changed every 5 years. If your boat actually has 22 years on the original bellows, it would not surprise me if you have water in there. I would pull the drive before I put it in the water again.

Ok, so I pulled out the nice little OMC book that came with my boat. Yes, it says to grease the Gimbal bearing every year and I have stuck the grease gun to it each year. However, I have NEVER pulled the drive to grease the U-Joints like the book and you folks say. I remember ONE TIME about ten years ago when I had a boat place do it. That is the one that screwed up the lower shift cable. So, the book insists that if I pull the drive, I need to align the engine, which I do not have the tools or skill. So, do I take this thing to the dealer, if I can find one left and have them grease the U-joints and while they are at it, check the lower shift cable? Or is this a good time to also replace the unsafe throttle control that does not need the safety catch to be lifted to go from nuetral to forward or reverse? Lottery tickets are a must! Thanks Bob

 

[bruceb58]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Just so you know, pulling the drive can't stretch the lower shift cable. Unless they remove the shift cable from the pivot housing, which there is no reason to do, it would be impossible for maintenance to cause that. i would be more worried about taking it to the guy that told you that than the first guy that got accused of doing it.

 

[sea wolf]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

I told you I need a Four Winns repair place in Minnesota. I am mechanically inclined but not to smart on the outdrive! Can you tell?

Ok, the screws I pull on the drive, sorry no book in front of me, there are two vent screws on one side and one on the other. In fact, when I was reading one post, one screw that I am sure I pull every fall had a sticker post that said, "NEVER REMOVE THIS SCREW" Wow. Yup, wondering again. But no book handy, as I am at work. So, I was wondering when this hose is drained, does it not drain this pump? Am I just getting lucky?

So, that said, the cooler sits at a 45 degree angle and the hose I am draining goes to the top of this cooler. The bottom of it has a hose that goes to the outdrive?

As far as doing anything with the bellows or U-joints, I have never done anything! Never knew other than to change drive grease. I need to look up the bellows and U-joints as I know NOTHING about them!

So, if I decide to switch to a new stern drive, should I just wait and pull all this and sell it on craigslist? Wow, such decisions.

Thank you all. You are a very smart bunch. Makes me feel stupid!!! Bob

Forget about the dealer. You need a mechanic who knows how to work on that Cobra, especially the shift cable adjustment. That thump your hearing is caused by an out of adj. cable or it's shot. If it's not done properly by someone who knows what their doing you're asking for trouble. Hopefully, the damage isn't already done.

No way would I take the boat out with the problems you're having with it, including that shifter.

 

[Ski Bob]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Sea Wolf. Thank you very much. I appreciate your honesty here. I WILL NOT put it back in the water until I do these things. So, for those of you that helped me along the way, I thank you. I have learned more about this Cobra in the last three days than in the first 22 years I have owned.it.

So, I am going to have the lower shift cable looked at and adjusted or replaced.
Remove the drive to grease the Gimbal bearing, U-Joints and shaft.
Replace the shift lever. It has been keeping me on my toes! Dangerous condition that will haunt me if I let it go!
Replace the drive grease with the same Eviinrude/Johnson Synthetic.

Again, thank you all so much. I will do it right away. Oh, by the way, I will need someone's credit card number though.

 

[HT32BSX115]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Sea Wolf. Thank you very much. I appreciate your honesty here. I WILL NOT put it back in the water until I do these things. So, for those of you that helped me along the way, I thank you. I have learned more about this Cobra in the last three days than in the first 22 years I have owned.it.

So, I am going to have the lower shift cable looked at and adjusted or replaced.
Remove the drive to grease the Gimbal bearing, U-Joints and shaft.
Replace the shift lever. It has been keeping me on my toes! Dangerous condition that will haunt me if I let it go!
Replace the drive grease with the same Eviinrude/Johnson Synthetic.

Again, thank you all so much. I will do it right away. Oh, by the way, I will need someone's credit card number though.

I had an original OMC shift quadrant in my 87 Liberator when I pulled the engine/drive.

It was working but fairly worn out so I replaced it with a Teleflex CH-1700

As a minimum, (after 22 years of NO transom maintenance) you should be installing a complete transom service kit. That will include a drive and exhaust bellows, new gimbal bearing, gaskets clamps, etc.

You can buy the kit right here on iBoats, although you can shop around and you might find it cheaper.
Bellows Kit for OMC Sterndrive Cobra, GLM 21962 - Sierra 18-2771 - iboats



The drive removal is not all that hard and alignment is fairly easy too..........you just need an alignment tool and a little patience!

Don't know if I said it (I think Bruce did) Mercury, Volvo and I think OMC recommend removing the drive and checking the alignment every year.

The problem is that engine mount points move, shift, and (stringer) mounts get rotten over the years. Checking the alignment catches those changes before the coupler fails. (you have to remove the drive and engine in that order to replace the coupler)

You dodged that bullet too! I wish I was that lucky!

 

[Lou C]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Yep you need an OMC mechanic if you can find one. If the drive has been off only 3 times in 22 years, it might be a struggle to get it off, esp if there is water in the bellows and rusty ujoints, driveshaft, etc.
The noise could be ujoints, or the gimble bearing, The clunking is your clutch dog in the lower unit which is either worn out, or the cable is not adjusted to allow the clutch dog to fully engage in fwd and rev.
The shifter (is it an OE OMC control?) you just have to replace. The OMC OE controls were good but they do wear out. And if you want to go to a different drive system, it makes sense to replace it with something that can be set up to work with a Merc or Volvo system. The OMC will work only with OMC drives.
Too bad you have not had the pleasure of driving it with a good shift cable and not worn clutch dog. A properly set up Cobra shifts great. I'd rather have a properly rebuilt Cobra, than an SEI drive anyday because of things I've heard about the quality of the gears on those units.
One thing to keep in mind, is any I/O you can buy are all labor intensive machines. They all take work to be reliable. A modern outboard, while more expensive (maybe not now with I/Os having to have cat converter exhaust) is cheaper over the long run, less work, and safer. Keep that in mind for future boats.

 

[Ski Bob]

Re: 1991 Four Winns 4.3 Cobra overheat and now stern drive noise

Ok, for those of you still glancing at my issues, here is where I am at. I changed the lower gear lube and greased the Gimbal bearing. I had also replaced the thermostat and flushed ALL the hoses to make certain there were no obstructions. I panic'd too soon on the power steering cooler winterizing as it tilts downward. Therefore, when I pull the hose from the stat housing and lower it to the bottom of the engine compartment, it IS draining out the cooler. So, feel better there. Also, as stated, I removed the cover on the lower unit and pulled the impeller off to check it. It looks BRAND NEW. So, today I took the thing to the lake and ran the heck out of it. It ran solid at 170 degrees at idle and 175 degrees under high speed and RPM. In other words, I worked the boat for a solid hour. Never a temp issue and the lower unit sounded ok. THe only concern left now is to repair the shift lever where after close inspection, the little tabs that are the stop for the shifter from neutral to F and R is chipped off. Needs a replacement part. Second, I need to have the drive pulled and the U-Joints greased and the bellows checked. So, again, thank you all for your help. Happy boater today! Bob