Impeller housing overheating

[DGMan80]

I'll double check to see if it sits flush or not. I'll report back. I don't believe it referenced the Sierra number. I'll order the oe omc part number even if the old setup does sit flush. Worst case scenario if it ends up being the same and its something else is wrong I'll have a backup.

Ok here's the update, the boat sits at a good friends house who's got a shop and property. He's an automotive mechanic who's got everything under the sun to work on cars. Unfortunately he knows zero when it comes to boats. But having the proper equipment is half the battle. The other downside is said property is thirty minutes away which makes all work on it a planned event. Anyways back to the conundrum... I'll stop right here and say thank you to everyone with ideas and advice! I tried everything! The housing did in fact sit flush. I verified that the small fitting on the housing was pissing water. I also ensured I was getting full flow through the muffs by clamping them in place against the drive. This allowed next to no water to escape from the muffs while the water was running. I Fired up the engine and it started overheating again. Shut it down. I grabbed a backup emergency impeller from the extra parts box I found in the boat. Clearly used however in great condition. I greased it up threw it in and it worked like a champ! Ran it for about 3 minutes impeller housing was cool to the touch. Good to go! I've read that there are two that are close in size and I must have gotten the larger of the two. Looking at the two side by side it was hard to see a difference. I was able to identify the leaking freeze plug and I replaced that. While trying to diagnose the water flow issue I pulled off the thermostat housing. And it looked like the original tstat. I managed to chisel it out And ordered a new one. Ran the old housing through a media blaster and got got it all cleaned up. Put some new houses on and just waiting for the new thermostat. It will be here Monday. Hopefully I'll get to work on it during the week this week. Once I get that thermostat in I'll be able to check for any other water leaks and go from there. Besides that I'm ripping out the interior side panels as there was some significant water damage. I'll be reglassing that back in and then putting new side panels in. After that I can get her in the water and ensure everything runs as it should.

 

[alldodge]

Bit late now, but wonder if the height of the old and new impellers are the same

 

[PITBoat]

Thank you very much for the info! I'll be tackling this in the spring I think.

I had to replace my batwings last summer, after an overheat on the lake, of the left side one. Started smelling smoke on plane, and the temp gauge was up some. After stopping, I didn't see any flames, but there was enough crackling sounds that I discharged a small amount of the extinguisher in there.

The water passages inside them were clogged with rust. Temp runs cooler now all the time, like between 120 and 180F on the gauge.

 

[Lou C]

I think what you might have experienced was the slight mismatch between an OE housing and aftermarket impeller or vice versa. Start out with all OMC original parts and you will not have that problem again; I haven’t and I’ve owned this boat 18 years and probably changed the impeller at least 4 times.

 

[DGMan80]

I think what you might have experienced was the slight mismatch between an OE housing and aftermarket impeller or vice versa. Start out with all OMC original parts and you will not have that problem again; I haven’t and I’ve owned this boat 18 years and probably changed the impeller at least 4 times.

That's what's weird. I ordered the whole kit including the housing. Going forward I'm only ordering OE unless it's not available. Would you say changing it every other year would be too much?

 

[Lou C]

That's what's weird. I ordered the whole kit including the housing. Going forward I'm only ordering OE unless it's not available. Would you say changing it every other year would be too much?

Well if you stay out of shallow sandy water I’d say they are good for at least 3 seasons if you use OE. Each year when I start mine up I judge it by how much water is exhausting under the transom mount.
Did you use GLM or Sierra?

 

[DGMan80]

Well if you stay out of shallow sandy water I’d say they are good for at least 3 seasons if you use OE. Each year when I start mine up I judge it by how much water is exhausting under the transom mount.
Did you use GLM or Sierra?

The one that didn't work was an Amazon one. Manufacturer UANOFCN. Not sure the one I grabbed from the boat used, that did work. The one that I ordered is a sierra kit. Good to know on the replacement life. I'll keep an eye on it. Thanks again for all the help!

 

[Lou C]

My suggestion is to use OEM for impellers and driveshaft bellows because these are parts you don’t want to fail. There are a couple of good online sources for original OMC parts if you look around of if there is an Evinrude dealer local to you they can order them. We can’t post other vendors on this site but do a search you’ll find em. The impellers last at least 3 seasons normally and the driveshaft bellows can last as long as 10 years if you store the boat with the drive down. Replace the bellows when you see small cracks forming in between the folds. Tilt it up to check.

 

[Lou C]

Also:
You might want to check the gear oil for water (pull the bottom drain plug and check the condition of the gear oil)
Remove the drive & check the inside of the driveshaft bellows for water, and the gimble bearing and u joints for wear & corrosion. This is standard I/O maintenance. On the Cobras it is advised to clean out the bell crank area in the pivot housing because built up deposits will cause sticky shifting.
The Cobra drive when set up properly with a good shift cable in proper adjustment with the ESA working right and idle speed to spec should shift very easily into and out of gear.

 

[DGMan80]

Also:
You might want to check the gear oil for water (pull the bottom drain plug and check the condition of the gear oil)
Remove the drive & check the inside of the driveshaft bellows for water, and the gimble bearing and u joints for wear & corrosion. This is standard I/O maintenance. On the Cobras it is advised to clean out the bell crank area in the pivot housing because built up deposits will cause sticky shifting.
The Cobra drive when set up properly with a good shift cable in proper adjustment with the ESA working right and idle speed to spec should shift very easily into and out of gear.

Should idle be between 800-900 rpm? Or is that too high? How hard is that drive to remove? Also what should I be using to remove any deposits if there are any? Sorry for all the questions, trying to do it right and not screw it up. I'm fine digging in and getting dirty, I just need pointed in the right direction and I'll get after it! Prior to burning up the last impeller it did shift fairly smoothly from forward/neutral/reverse. Just the slightest stutter and a mild click between gears.

 

[Lou C]

That’s too high it should be 500-600 in gear in the water you can set it at 600 on the water hose on land then it will be close.
The drive is not hard to remove as long as the bellows did not leak and allow corrosion to rust up the splines on the driveshaft in the engine coupler.

 

[DGMan80]

That’s too high it should be 500-600 in gear in the water you can set it at 600 on the water hose on land then it will be close.
The drive is not hard to remove as long as the bellows did not leak and allow corrosion to rust up the splines on the driveshaft in the engine coupler.

Thank you!

 

[DGMan80]

I hate when people never update so here's an update. Got the interior mostly tied out still working on a wall for the transom and installing some sort of folding seats on either side of the doghouse. Got her on the water last weekend, she ran great considering there was 40 gallons of 7 month old fuel in the tank. She cruised at about 28 mph at around 3400 rpms planes nicely and steering was just fine. Above about 3700 rpms it would start backfiring a bit. I'm assuming is the poor fuel and not timing. I've gotten it down to about 25 gallons at this point and I'm going to run it one more time this weekend to try and get it down below 15 gallons in there. I've added some fuel additive to hopefully help with getting any water out of the fuel. Is there anything else I should be doing short of pumping it dry and filling it back up? The other issue I had was it shifting into neutral after being in gear. After previous discussion I realized that we never adjusted the idle prior to getting on the water. I managed to do that on the water the second time out and it seemed to fix the issue it still shifted hard the first time, then after that it worked pretty smoothly. I'm taking her out again this weekend and will see if the fuel additive helped at all. I'm mostly running lower rpms so no concerns as far as motor performance. Would it be beneficial to change the inline fuel filter as well? Thanks again for everybody's help, this has been a rollercoaster of a project but overall it's been very positive thanks to the feedback.

 

[alldodge]

Don't see the fuel as causing a backfire, its not that old
Recheck your timing
If timing is good, then check compression, might have a valve hanging

 

[Lou C]

I don’t think that fuel is old enough to cause a backfire. Backfires (thru the carb) can be caused by a lean fuel mix and perhaps an intake valve hanging open.
Keep in mind these engines came with a Prestolite points distributor and Rochester 2 or 4 bbl carbs and both require maintenance for the engine to run right.

 

[DGMan80]

Thank you guys for the feedback. Can I time it on the muffs? It'll be a challenge if it needs to be done at the dock lol.

 

[DGMan80]

Anybody have an issue after running the throttle up, of it not dropping back down to base rpms? It seems to stick at about 900 is that something I can adjust at the linkage?

 

[DGMan80]

Had a weird thing happen today. Last run out on the river to run the gas down some more before throwing new gas in it. Ran out to fish for a couple hours. The current was dead and decided to troll. Ran at idle for about thirty minutes motor dies nothing new at idle (possible timing) I'll check it tomorrow. Go to fire it up and starter clicks. Fire up the kicker motor and head four shore. Get back to the dock and it I try to start it again and it cranks very slowly like a dead battery then nothing again. Tried a few more times seems like a dead battery. Of course I've got no backup battery. I park the boat goto the store and pickup the backup battery. Have it installed in about 5 minutes. Goto fire it up and same thing. It's been sitting for about thirty minutes at this point and it cranked easier for about 5 seconds before it died. Pulled the boat out of the marina at this point and took it home. Get home throw the muffs on and it fired right up no issues. Let it idle for 5 minutes no issues. Took it back to the water put her in and ran it at idle for thirty minutes up and down the river no issues. Ran it up on a plane for about ten seconds (river was packed !!! Nowhere to go) put it back on the trailer scratching my head. Any ideas on what could have caused the starting issues? My mechanic friend thinks it was something electrical related. I'm clueless at this point. I'm going to try and get this thing timed tomorrow and go from there. Thanks again for any feedback.

 

[Lou C]

Starter terminals, battery terminals and battery cables. All must be free of corrosion clean & tight. Sounds like resistance at the terminals/corroded cables. Any bad wiring or terminals in the starting system can cause this....

 

[DGMan80]

Starter terminals, battery terminals and battery cables. All must be free of corrosion clean & tight. Sounds like resistance at the terminals/corroded cables. Any bad wiring or terminals in the starting system can cause this....

I started digging first thing this morning, sure enough found a ground and power wire loose. Power was corroded and I had to wirebrush it and tighten it down. Looks like the ground cable was barely held down with a bolt. I went to tighten it and its the wrong size! I dug through my "bolt bin" found one that did fit. Everything else looks pretty clean and tight. It's a bit tight back behind there hopefully I didn't miss anything. I'll be taking the whole family out on the river for the first time tomorrow. Wish me luck! I topped off the kicker motor just in case lol.