Hello all,
I could use a little help. My Suzuki dt140 has been overheating. Recently the cooling stream (aka pissed hole) is barely outputting water when planing. On several occassions after planing, I tried to trim up the motor only to find the engine overheating and shutting down. My first reaction would be a damaged or worn out impeller but have not inspected it. Before this, the stream was strong and healthy when I ran the water hose up to the engine powerheads. This would suggest that the hole is not plugged up but instead suggesting that there maybe problems with the impeller. Has anyone done an impeller replacement recently on this type of Suzuki engine? How difficult is it for a newbie. The other major problem that I currently have is the low RPM at WOT. I could not get the rpm past the 5000 mark. The recommended rpm at wot is between 5200-5700 rpm. I previously was able to get the rpm closed to 6000 but not anymore. Could the overheating problem related to the low rpm? I have not been able to get good info on various chat forums. ie Iboats, etc. Any help and assistance is greatly appreciated.

I posted too quickly and left out some key info so here it is.

It is 2001 Suzuki 140 2-stroke engine with roughly 200 hours. It appears that the time needed to plane is longer than usual based on seveal observers so shooting out of the hole is a problem. The boat is 1960 Fishmaster so roughly 2200-2300 lbs. No compression has been performed.

My3 Sons
I have a 2000 DT115, pretty much the same motor. I also have the shop manual. If you are interested, I will scan the pages associated with the water pump impeller replacement and email them to you.
I will also check the book and see what I can find in regards to your low rpm issue. However, (going from memory) I believe that an overheating problem will cause the engine to retard its timing to keep its rotation at a much safer rpm- somewhere around 2000. Let me know if you are interested, I will log back on tomorrow (Wednesday) and check...

hi ramcr913,
thanks for the info. I recently purchased the service manual from Seloc, I believe. The instructions are very general and very few illustrated pix for the dt140. Having not done any marine work before I am a little reluctant diving in. Hence, I am writing to this forum seeking any advice/suggestions. As for the low rpm, like I mentioned above, I could only get just below 5000 at wot. You are correct about the rev limiter around 2000 rpm when the motor temp is high. I did not see the rev limiter light the last time when the engine cut-off. At this point, I don't want to spend the expense to get the compression done given the age of the motor. I plan to replace the impeller/gasket soon when the parts come in. Could the stuck thermostat restrict the water flow giving false indication of a damaged impeller? Again, the cooling stream appears very weak at idle. I could not get a good visual of this stream while running. I suspect that it is weak since I could see white smoke just below the powerheads. btw, do you know of a good website to get Suzuki engine info for repair work?

Go check the forums at http://www.iboats.com. I've done one on a 115 Evinrude. Not sure if there would be that much difference on the Suzuki. Helps if you have 2 people sliding it off and then back on. One trick is to make sure that the water intake tube is lined up when putting it back on and put dish soap on the rubber grommet so it slides on easy. I had to pull mine back off because the grommet got pushed into the impellar housing. Water came out everywhere on the lower unit that's the sign that you don't have the water intake tube lined up. I did it myself using the OEM manual and a little help from my wife putting back on. Good Luck, you can do it. You can also order the impellar kits from iboats or I got mine a http://www.marineengine.com . It's best to get the kit with the housing and all because you don't know what the real problem is until you get in there and the kits are cheap <$20.

whitesmoke under the powerhead is a horrible sign!!

This is not the time to "do-it-yourself" You should bite the bullet now and have a professional check it out.

Steve is correct; the white smoke is not a good thing. You need to get it checked out. Also, Browns Point Marine carries a lot of Suzuki parts. http://www.brownspoint.com/
Good luck.

Ok guys. Who locally is a reputable service shop to call for Suzuki work? Any particular person I should talk to?

Where are you located? How long have you been running with the overheat condition? Steve has a good point wrt having a pro look at it, if you have been continuing to run it while overheating get ready to buy a new power head $$$$.

I live north of FW. This overheat condition has been there the last three fishing outing. At first I thought it may just be improper trimming of the motor during take-off and possibly bad impeller. Because of the eng cut-off overtemp feature I did not give it immediate attention. It maybe a costly decision. What cause the white smoke under the powerhead during take-off? thanks so much for the help.