1998 DT 140 Overheating...Please Help

[dloves82]

Just installed new impeller and wear plate, impeller housing and thermostat in my dt140 today and still overheating. I can run at about 5000 rpm for 10-15 minutes and then the overheat alarm sounds and rpms drop. It seems to be peeing ok at low rpm but kinda slows at high rpm. I'm being told that my water jacket may be clogged but when I run water through the pick ups with the hose there seems to be good flow. The motor on a 1999 Key Largo 190 Bay that's in pretty good shape and I'm trying to decide if it's worth putting any more money in the motor or repower. Any suggestions would be appreciated. BTW, thing about an E-Tec and any suggestions there would be good too.

 

[Marion Moore]

Re: 1998 DT 140 Overheating...Please Help

I have the EXACT same problem and have taken the EXACT same steps to correct it. I have a '97 DT140 EFI. I have inspected my thermostat and it seems fine. I may just waste some more money and replace the thermostat to stimulate the economy.

Let's keep in touch and maybe we can work this out together. Send me a PM with your email address.

 

[cousinabe]

Re: 1998 DT 140 Overheating...Please Help

How does the water pressure valve look? could be not seating well causing water to dump out and not reach the top cylinder area.

http://store.brownspoint.com/dt140/fig001-1408601.asp

 

[Marion Moore]

Re: 1998 DT 140 Overheating...Please Help

I don't want to hyjack dlove's thread but I KNOW my water pressure valve was replaced back in March 09 when I swapped power heads. Here is a picture of the old one. It looked OK but for $12 I thought I had better change it while the head was off. I guess that doesn't mean something couldn't have it stuck open... hmmmmmmm. I hate to have to pull that head again expecially now that summer has kicked in.

 

[dloves82]

Re: 1998 DT 140 Overheating...Please Help

Haven't checked the water pressure valve yet Cousinabe, looks like a pain but hopefully worth it.

Marion, you can hyjack this thread all you want, especially if we can both figure what the heck is wrong.

 

[Marion Moore]

Re: 1998 DT 140 Overheating...Please Help

6/27/09 Update
Swapped water pump housings with another lower unit that I have. Used my new impeller and base plate of course. Did a test run in the river for about 30 minutes. The whole time I ran from 4000 rpms, which is what I normally run, all of the way up to 5500 and back and fourth. Never had the overheat alarm to sound. Checked the head temperature by touch. I could only hold my hand on the top of the power head for about 5 to 7 seconds before it became too hot to stand. Did notice as with almost every other trip that the tell tale water stream was very strong when the engine was started (thermostat closed) then it became weak as the engine warmed and ran (thermostat open). I need to test it in the bay where the water temperatures are running in the 80's before I call this one fixed. Not real sure what to do next.

 

[Marion Moore]

Re: 1998 DT 140 Overheating...Please Help

Is there a Suzuki service bulletin to cover the pressure valve on the '97 and later DT115/140's? Maybe one of you experienced techs can help me with this... My service manual (99500-94516-01E) goes up to the 2000 models but does not have any information on the pressure valve, where it is located, function, nor is it included in the troubleshooting section. The only clue that I had that it existed was looking at the parts break down on Browns Point Marine.

dlove, I'm thinking you should probably change your pressure valve. I don't know how much a shop would charge or if you are really brave you could try it yourself. The part is cheep ($12 plus $25 gasket) but it is a great deal of work. Even if it costs $300 that is a lot cheeper than buying a new Etech ($10k +/-).

 

[Marion Moore]

Re: 1998 DT 140 Overheating...Please Help

Fished today, ran to the jetties, back through the waterway, and down river. Engine never overheated. So... I guess I fixed it. I'll keep my eyes on it of course.

Swapping the impeller housing may have done it. For today's run I also put my 4 blade ported Power Tech prop back on. It may be possible that the prop could have helped out as well.

Wouldn't you know it, I ordered the engine holder gasket ($30) so I could remove the power head and inspect the passages and pressure valve. If it ever overheats again I will pull the head.

 

[dloves82]

Re: 1998 DT 140 Overheating...Please Help

Between work and more work I haven't had much time to play with the motor problem untill today. I may have found the problem, even though I had good compression in all cylinders my gut was telling me it may be a head gasket due to the steam I was getting. I pulled the heads off today low and behold it looks like the heads and tops of the pistons have been steam cleaned, the heads look brand new on the inside. Just ordered the parts from Browns Point and will be anxiously awaiting their arrival. Hopefully, I will be adding a post next week declaring problem solved.

 

[Marion Moore]

Re: 1998 DT 140 Overheating...Please Help

You probably found your problem. Head gaskets are a lot easier to replace than the engine holder gasket.

Be sure you torque the head bolts correctly when you put it back together.

My engine did fine this past weekend. That's two trips. Maybe I did manage to fix it.

 

[dloves82]

Re: 1998 DT 140 Overheating...Please Help

What a crappy day, got my parts in and put in the new head gasket and still overheating. I guess I'm jumping into the frying pan and going for the water pressure valve next.

 

[Eshaw150]

Re: 1998 DT 140 Overheating...Please Help

look in the lower unit at the exhaust rubber and chek to see if it is leaking

 

[dloves82]

Re: 1998 DT 140 Overheating...Please Help

If you're talking about the rubber near the water pump with the stainless bent plate, it's new. Except for the rubber grommets around the pick up tubes the lower unit is new in regards to the cooling system. A few people have suggested the water pressure valve so I'm trying that next. Everything is disconnected, just need to lift the engine off.

 

[Eshaw150]

Re: 1998 DT 140 Overheating...Please Help

If you're talking about the rubber near the water pump with the stainless bent plate, it's new. Except for the rubber grommets around the pick up tubes the lower unit is new in regards to the cooling system. A few people have suggested the water pressure valve so I'm trying that next. Everything is disconnected, just need to lift the engine off.

try that then since u got it all off

 

[Marion Moore]

Re: 1998 DT 140 Overheating...Please Help

dloves, please pay attention to the orientation of the valve and let me know how it is installed. I think the spring is down? Just curious.

 

[dloves82]

Re: 1998 DT 140 Overheating...Please Help

Marion, you are correct the spring was down. The valve seemed to operate correctly but there was a lot of corrosion around the seal, I don't think that affected the function of the valve though. Eshaw got me thinking with the question about the exhaust rubber. When I replaced the old rubber, there was an area where the rubber seals against the divider that seperates exhaust chamber from the water pump that had corroded away pretty bad. My guess is that it's leaking exhaust into the water chamber. I guess that would cause overheating also. I'm thinking while I'm waiting for the parts to arrive I could try building that area up with J B Weld to get a better seal. Anybody have experience using J B Weld in that manner. If this next round doesn't fix the overheating, I'm really considering a repower, I'm at my wits end.

 

[Eshaw150]

Re: 1998 DT 140 Overheating...Please Help

Marion, you are correct the spring was down. The valve seemed to operate correctly but there was a lot of corrosion around the seal, I don't think that affected the function of the valve though. Eshaw got me thinking with the question about the exhaust rubber. When I replaced the old rubber, there was an area where the rubber seals against the divider that seperates exhaust chamber from the water pump that had corroded away pretty bad. My guess is that it's leaking exhaust into the water chamber. I guess that would cause overheating also. I'm thinking while I'm waiting for the parts to arrive I could try building that area up with J B Weld to get a better seal. Anybody have experience using J B Weld in that manner. If this next round doesn't fix the overheating, I'm really considering a repower, I'm at my wits end.


r u talking about the rubber or the metal plate

 

[Marion Moore]

Re: 1998 DT 140 Overheating...Please Help

dloves, yeah, try to build it back with JB weld. Any area that could leak exhaust back into the intake can definatly cause a problem. Also, make sure there is no leak between the water pump base and the water intake channel. I had to use some sealant on mine. Must have worked.

 

[dloves82]

Re: 1998 DT 140 Overheating...Please Help

Eshaw

There is a barrier on the extension case that seperates the chamber the water pump is in from the exhaust chamber. This barrier comes in contact with the exhaust rubber when when you install the lower unit. The area I'm talking about is on the center portion of the barrier that would be directly over the rubber, I'm starting to think exhaust may be entering the water pump area and heating the water pump causing the engine to overheat.

 

[Eshaw150]

Re: 1998 DT 140 Overheating...Please Help

i am aucutally in the same problem my metal plate rubber is flaaen apart i auctually had to order a new bearing carier cause the aluminuim disolved what happened is the air from the exhaust us getting in there and causing the pump to loose its prime