2000 johnson 25 j25tessd overheating and SLOW at WOT

[jakedaawg]

Could this problem be caused by the stator? Or the timing being off? As I dig deeper and deeper into this outboard I continue to find no problems. I'm starting to think maybe it was electrical all along.

I thought you found a diverter that was missing/damaged/out of place?

 

[jasper60103]

Could this problem be caused by the stator? Or the timing being off? As I dig deeper and deeper into this outboard I continue to find no problems. I'm starting to think maybe it was electrical all along.

Kloctower, I thought you were chasing a overheat problem?

Lets backup for a moment.
What were the symptoms of the overheat?... e.g. limp mode, the head was too hot to touch, etc?

FWIW. Here's a pic of my motor with the head off. It shows one diverter at 12 o'clock and two more straddling 6 o'clock.
Your motor may differ.
Also, you mentioned the tstat was missing from yours, which indicates someone has been
messing around in there.

 

[Kloctower]

Yes sir someone was definitely inside the head and our Motors match my water diverters are located in those same three areas. Yes I found a missing diverter and a second damaged diverter but I don't think that would cause this big of a problem do you? The symptoms are overheating and reduced power at wide open throttle. It goes down to half throttle and surges up and down in RPMs once it gets hot. When I first start the motor up in the morning it will run balls out for about 3 minutes and then it starts this problem. I have tried everything with the fuel system I own three different tanks I've tried it with and without filters. I bought a new connectors and lines including the connector on the motor and the line on the motor. I rebuilt the fuel pump rebuild the carburetor replaced all the electronics except what's under the flywheel. rebuild the water pump and I have the head off right now as well as the exhaust cover. I have not found any problems except the missing diverter. Although the head has a low spot in the middle between the two cylinders. The old head gasket and does not appear to have been leaking water or losing compression between the two cylinders even though the head does have a very small low spot in the middle. .004 is the maximum tolerance for head warpage and I believe I'm somewhere around .001 or .002 on the head but I wonder if the block could also be warped and that would possibly put me out of spec if it were in the middle like the head is. My question is would a warped head cause this overheating problem? When I have no issues until it warms up it makes me believe it's water related but I have a strong flow in a new pump with no restrictions so far in the jackets. Thank you all for your time and your help I very badly want to get to the bottom of this. What do I need to look out for when pulling the powerhead? I am working on this right now are there any tips and tricks you have so I don't mess anything up?

 

[jakedaawg]

As stated before, the diverter can cause all these problems. Fix em, put it back together, compression test, and go boating. Dont borrow trouble, you had an issue, you found a problem, fix it. Try again. Most likely it will solve it. Those little rubber tubes are very important.

Just make sure you back flushed it to get all the old pieces out.

 

[interalian]

Before you button the head back on, resurface it on a flat surface like a piece of plate glass. Put a piece of medium grit sandpaper or emery paper on the glass and work the head in a figure eight pattern until the entire gasket surface is evenly finished. This will remove the high spots and ensure the new gasket seals well. It is unlikely the block is warped, but sometimes the bolt bosses are a bit proud of the rest of the area due to torquing - check with a straight edge.

 

[jasper60103]

Also, did you say the water was cold coming out the exhaust?
I would check that again after you put back together.
I think the lack of a tstat and diverter were working against you.
The water coming out the back of the leg should at least feel warm even at idle after a while.
Here's how I check mine...

 

[Kloctower]

Thank you all for your replies and for sharing your information. I have already resurfaced to the head with sandpaper and glass. I have had to do that one before. It is now less than .001 off. I remove the lower unit and looked up the water tube there is some type of hard crustacean like build up inside the water tube by the bottom. I'm going to pull the water tube out and clean the entire thing. The water coming out of the Telltale was cold even when the motor was hot the water coming out with the exhaust was hot. Thank you all for your advice but I honestly don't feel like I have found the problem yet which is why I have not put the motor back together I understand the diverters are important but they can only help water flow if they're missing. I really think there is an obstruction somewhere and I may have found it in the water tube. How do I post pictures all of mine are too large?

 

[jakedaawg]

Photo resize app works for.me.

The diverter missing would actually impede flow believe it or not. They are used to direct the water in the right direction and when missing can keep water from flowing. Right hand, true story.

The missing one is probably lodged somewhere hence the backflushing.

 

[racerone]

Kloc----You misunderstand the purpose / working of the diverters !---------And water does not flow thru these tubes.-------These tubes guide the water around the block for proper flow and cooling.-----Look , listen and learn.

 

[Kloctower]

Kloc----You misunderstand the purpose / working of the diverters !---------And water does not flow thru these tubes.-------These tubes guide the water around the block for proper flow and cooling.-----Look , listen and learn.

I understand the diverters. It's in the name. What I ment and said was the water can flow easier without one of them. Maybe the water does not flow to the right places but it can definitely flow more freely without them in. I don't know how you misunderstood what I'm saying but when I said water tube I literally meant water tube. As in the tube that connects the water pump to the powerhead. I was not referring to diverters as any kind of a water tube. When I said water tube I meant water tube. When I said water passages I meant water passages. I am not a certified outboard mechanic. But I am a professional mechanic in the automotive industry I work for Cooper standard Automotive they are a massive company and I work in a massive Automotive manufacturing facility fixing machines that manufacture car parts including robots and pneumatics hydraulics so on. I'm not a cuck I understand what I am talking about and I understand what you are saying. I'm asking for advice because I am not familiar with the internals of an outboard motor but am no stranger to what they do I just need help in some areas. I do listen and I do want to learn but I think you need to read and understand what was typed before you make that kind of a comment to me. I am very appreciative of all the help you guys are giving me. I am grateful for the advice of you experienced outboard mechanics.

Can I remove the water tube from the lower unit or do I have to go under the powerhead 2 detach some bracket or something holding it on? I've seen them with a flange that's bolted down before but I don't know how mine is attached. Does it just pull out? I want to check the entire water tube for obstructions because I found one right at the base of the tube by the water pump. It was a mixture of hardwood and dirt that had stuck to the wall of the water tube and hard and there it was blocking half of the tube I think there could be more.

 

[racerone]

Well, a missing diverter does NOT help water flow as you are assuming according to post # 27 ---nuff said.

 

[Kloctower]

No Title

Thank you so much for the idea of the photo resizing app. I did not know those existed. I will take more pictures of the problem when I get home. Can I remove the water tube through the lower unit?

 

[Kloctower]

Well, a missing diverter does NOT help water flow as you are assuming according to post # 27 ---nuff said.

What I said was it would allow water to flow through the head more freely racer one. Obviously not having something to flow around would cause water to flow more freely. It is simple physics. I'm not saying it would help the motor cool down I'm not saying the water would get to where it needs to go. What I'm saying is simply from a physics standpoint that without the diverters in place the water will be able to move more freely. That is an indisputable fact proven by physics. Water flows more freely without obstructions hence beaver dams. Now you have made three or four comments on my post so far and all of them have been negative in one way or another I appreciate knowledge and help but I do not appreciate you insulting my intelligence multiple times by calling me a novice in your first post about The Telltale and telling me to listen when you clearly did not read my post. And so far what you want me to listen to is not helpful in anyway or someone else has already suggested it. You do not know my level of skill your assumptions are making you look bad buddy. Now I am trying to find help fixing my outboard motor I like this forum and the people on it. So far you are the only negative person I've met. If you don't have anything nice to say why waste your time posting? You're wasting your own time to insult someone you don't even know. I'm going to ask you kindly to leave it alone. I kindly decline your help from here on out racerone. Thanks but no thanks. Now please leave me to find and fix my problem in the name of outboards. I don't think your helpful. Nuff said.

 

[racerone]

Good luck with your project.---And you are not aware of my skill level on the 2 cylinder motor that you are trying to fix.

 

[interalian]

Biting the hand that feeds you...

Nevermind physics, the cooling system on these requires the water to follow a PATH around the engine: intake screen > pump > motor base/adapter > exhaust chest > around the cylinders (where the deflectors are - that's what they're for...) > into the head through one hole in the head gasket > around and out of the head and head cover through another hole in the head gasket (either after the thermostsat/poppet or other port depending on temperature/RPMs) > then out the bottom and back into the lake. If you don't have the deflectors/diverters in place, the water short circuits and you have problems, typically it bypasses the top cylinder.

 

[Kloctower]

I Don't consider it biting the hand. His comments were insulting and also they were all things already covered or very obvious. There's no need to be rude even if the person is a novice it don't make them feel welcome when they are insulted at the end of each replay especially when the replay is not helpful. Just clogs up the works and takes it in the wrong direction example is now. We're discussing his rude comments and not the motor. I understand what your saying tho and respect your opinion but that guy was rude. Not just on this post.

OK thanks that is very useful information I appreciate it. That makes a lot of sense because my top cylinder was the hottest and the bottom not so bad. I will clean the water tube out and replace the diverters then try again. Can I remove the water tube from the lower unit or do I have to tear into the top to get it free?

 

[interalian]

OK thanks that is very useful information I appreciate it. That makes a lot of sense because my top cylinder was the hottest and the bottom not so bad. I will clean the water tube out and replace the diverters then try again. Can I remove the water tube from the lower unit or do I have to tear into the top to get it free?

I have no idea what's needed to pull the water pipe on this motor as I've never had one open. Some (most?) require you pull the powerhead. Hopefully somebody else with that experience will chime in.

 

[jakedaawg]

Before Trying to remove water tube, put the power head back together and back flush in the tstat housing and out the water tube with the lower off. You can use a stiff piece of wire up the tube to dislodge any zebra muscles or whatever that started to grow there. Catch the water coming out of the tube in a bucket if you don't believe me. It's all in a typical days work at the shop, very common.

Its just so much easier to do it this way.

 

[Kloctower]

OK thanks Jake I will do just that thank you for saving me the hassle I really hope it works. You are right I might as well put it back together right now back flush and try it again I have nothing to lose if it works I'm done if it doesn't work I still have to pull the powerhead regardless of whether or not it works so I might as well try it. I am just worried there is more in the water tube but I will take your word for it I have plenty of different things to try as far as sticking something up the tube to dislodge more of it. Now that I got the head back in specs and all the surfaces cleaned up good I'm going to start putting it back together tonight after work. Why did the powerhead gasket kit come with two identical exhaust gaskets? There are two of the exact same exhaust gasket in the kit is this precautionary or do I need both of them when I reinstall everything? There is a gasket then the first plate then another gasket and the exhaust cover right? Because I have 3 gaskets when I only need 2.

 

[Kloctower]

Been super busy working 12-hour shifts and trying to finish my garage roof at the same time so the motors sits. I am putting the exhaust cover on now and then the head gasket in such hopefully have enough time and can get back to you guys I wanted to thank you all again for your advice and time. Fingers crossed hopefully this works and I can salvage the last few weeks of my duck season