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91 OMC cobra 23 engine

reneeweeks

New member
"I have 91 2.3 OMC cobra engin

"I have 91 2.3 OMC cobra engine,runs like a champ and does well with the boat but I was wondering what highest temp should go to running wide open for a long period of time go to.. If I run it wide open for a long period of time it will get up between 220 to 240 but when I back off just a little it cools right back down to 190 and just going slow and idling it runs 160..Does this sound about right or is it getting too hot?
Thank Renee"
 
"220-240 is too hot. I would

"220-240 is too hot. I would say that the hottest you want it for any extended period of time would be 190. Mine usually sits at 160. If i am wide open for a WHILE it goes up to 180. Lets see what everyone else says, but 220-240 I would say there is something a little wrong with the cooling system."
 
Yes I was thinking it was too

Yes I was thinking it was too hot also..Thanks for your input though..You know it was running like yours 160 to 190 but as I think about it we pulled up on a sand spot and I was looking at it and sand might have got into something back there and that it when it seem to do that after we left there..So what do you think?Think it might have got in the foot somehow?
 
"Definitely way too hot, you s

"Definitely way too hot, you should at the very least replace the impeller (how long since the last one?)"
 
"You know, the guy we bought i

"You know, the guy we bought it from changed it out so it is new changed it so he could get more start off speed to pull his kids around and it is small,I wonder if the thing is making it run hot because of the RPM's it is turning when going wide open and it is too many?Just trying to think of ANYHING it could be.."
 
"um...Denise, I'm talking

"um...Denise, I'm talking about the impeller inside the raw water pump in the drive, not the propeller that makes the boat go."
 
I'm sorry I have been thin

I'm sorry I have been thinking this thing in the ground and I am not sure about the impeller but we will check that first but what do you think about the propeller could it be too small making the rpm's to much for the motor to handle and making it heat up?
 
It runs really cool otherwise

It runs really cool otherwise just by letting some off the throttle...and cools down REALLY fast when you let off the throttle..Even runs cool when idling..
 
"OMC stopped making the 2.3 in

"OMC stopped making the 2.3 in 1990, is it possible the boat is a 1991 with a 1990 power plant in it? Post the engine model # if you can.

For the RPM's the 2.3 does rev pretty high, WOT (Wide Open Throttle) RPM's should be 5200-5600, does your boat have a tach and how high are your RPM's?

Your symptoms do match a worn out impeller, not able to pump enough water at higher speeds."
 
"Thanks ALOT guys y'all ar

"Thanks ALOT guys y'all are great and I will take your advice and change the impeller but first I guess i will have to find out about the year on it..I am not at home so I don't have the numbers on the engine but Friday I will get them and post them here ok?And thanks ALOT you guys y'all have been ALOT of help..
Thanks,Renee"
 
"Denise....a lot of times when

"Denise....a lot of times when dealers sell a boat, for example a 1991, if they have a brand new last years engine (1990) still in inventory they will install that to use it up rather than bring in another new engine. It's quite common to see, even in my own boat which is a 1990, it has 2 1989 engines in it. Doesn't really matter much but sometimes it's important to get the exact year of the engine/drive (power plant) due to changes made from one year to the next."
 
"Yeah I know that, just like w

"Yeah I know that, just like we have rv's and some of them have 2003 frames and the rv's are 2004.I did see in the parts on the impeller that a 1990 is different from the others and cost more..of course lol
Well I'll get that model number Friday when I get home and post it here.
Thanks Renee"
 
"Could any of you guys tell me

"Could any of you guys tell me where the serial number might be on that motor that tells the year model,I want to go out there and get it off tonight and I would like to just know where it is located so I can just go to it with the flashlight...I need to get that impeller tomorrow so we can put it back in the water this weekend..
Thanks, Renee"
 
"Should be on the rocker (

"Should be on the rocker (valve) cover, you want the model # and yours (if it's a 2.3) should look something like this 232BMRPWS"
 
232bmrpws...the PWS says it&#3

232bmrpws...the PWS says it's a 1990 model engine.

986030 is the model # of the stern drive which also says it's a 1990 drive.
 
Ok one more question if you do

Ok one more question if you don't mind????shifter is hard to move but we did find the problem the plastic connector that bolts to the engie is bending when we try to shift..It does fine if your idling but not trying to go..Do we need to replace that whole shift cable or can you buy thay black plastic peice?Or adjustments maybe?
 
"Need more description, are yo

"Need more description, are you talking about it being hard to shift into or out of gear. Or are you saying once in gear it's hard to increase the throttle?

Looking at the picture below are you referring to one of these shift cables or possibly the throttle cable?

290050.jpg
"
 
"When sitting at the dock, it

"When sitting at the dock, it will shift into forward and reverse just fine. Once out on the lake for a while though, it becomes hard to shift into reverse. We have had to shut the engine down, move to neutral, then start it up again to get it to go into reverse. We noticed that, after running for a while, trying to shift into reverse caused the black connector shown at the top of your photo (the one on the end of the red shift cable) to bend into the shape of a banana. We made a temporary fix by splinting the plastic connector with a metal bar, but are concerned that this may eventually damage the gears."
 
"Based on your description it

"Based on your description it really sounds to me like you are finding it difficult to shift into neutral from forward. It could be a problem with your ESA (electronic shift assist) or quite likely a stiff/binding lower shift cable (the bottom one in the diag) I believe the upper shift cable bending as you describe is a result of your shifting problem but not the cause. Have a read through this link from Stuart Hastings, the hard to shift problem is very well documented as is the process to replace/adjust the lower shift cable.

http://www.hastings.org/~stuart/cobra/"
 
"Bob,
I think we found t


"Bob,
I think we found the source of the overheating. We pulled the water pump housing and went trying to find a new impeller with the number stamped onto the old one. What we found was that the impeller that was in there did not match the housing. We've ordered a complete new water pump kit that includes the housing, impeller, wear plate, gaskets and all other parts using the housing number as a reference. You think that might get rid of our overheating problem?
We've also been doing some looking on the shift handle and have found that the throttle cable is hard to move. We removed the cable from the shifter and found that it shifts very easily with the throttle cable removed (but it was very hard to move the throttle when it was attached). We reconnected the cable to the shifter and disconnected it from the engine and saw that it was still hard to move. We can't find anything binding and the cable looks very new. Is there any way to lubricate those throttle cables or will we have to replace it?
Thanks."
 
"It's possible someone has

"It's possible someone has put wrong parts in there, hopefully the new pump assembly will fix you up but if not then let us know.

It is possible to have a sticky throttle cable biding the shifter up. You can't really lubricate them at all. Just make sure you follow it all the way back from the shifter to the engine and look for any sharp bends or it being wedged between something, other than that all you can do is replace it. Normally somewhere along the cable should be a sticker or label that indicates the length (or you can measure) they generally go up in 1 ft increments."
 
"Oh well, that didn't do i

"Oh well, that didn't do it. We're going to try replacing the thermostat. We think it also may be possible that the bottom water hose could be collapsing at high RPM's under load, so if the thermostat doesn't fix it we'll try that. Any other ideas? It does fine at about 3/4 throttle - will run all day long and stay under 180. 15 minutes at full throttle and it starts to climb over 200. Get back down to 3/4 throttle and the temp drops right on down."
 
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