[jackman1939]

I just purchased this motor, and after mounting it on my boat and turning on the ignition key, the unit on my center console beeped and the check engine light was on. I hooked up the serial cable to the motor and ran the diagnostic software from my laptop on it. I got 2 HARD codes 41 and 43 (these have to do with the Water Temperature switch and sending unit and associated circuits). Tried to clear the codes, the SW said they were cleared, but when I ran the test again, they were still there.I ran the rest of the static tests (fuel injector, oil injector, spark at each plug and fuel motor), and everything seemed to be ok. I started the engine, and it ran.I submerged the lower unit in a garbage can and filled it with water - ran the engine again, and the water pump appeared to be ok (water was chooting out the back like it should). I then removed each thermostat and ran the engine momentarily - water came out of the holes - that seemed normal. I replaced the thermostat covers, but left the thermostats out. Tried disconnectiog the WT sending unit and the WT switch - engine light still came on.I tried to start up the motor a few hours later, and it now turns over, tries to start for a second or 2, then stalls - now I can't even get it started.Day 2 - I tried to start the motor today, and it started up - seems like the only problem I have now is the 2 HARD error codes. Reinstalled the 2 thermostats. Motor started and I ran it for 1/2 hour at 800 rpm.Any help would be appreciated.thanks,Jack

[muskrat]

have you checked engine temp with temp gun.have you run motor in water beside garbage can.you need to verify engine temp & do you have a service manual to check sensors or grounding issue in wiring harness.

[jackman1939]

I don't know what a temp gun is.Have not run the motor in a lake yet - plan to do it Tuesday.I do have the service manual.After running the motor for 1/2 hour (with Hose hookup), I shut it down and felt the heads - I could out my finger on the head for a few seconds and not get burned. The water coming out of the motor while it was running was warm (not real hot).Other observations: o Tried dropping each cylinder while running at 1700 rmp. All cylinders decreased rmp to around 1200, except #3 (only dropped to 1400). o Motor sounds "clanky" - like car engine with noisy lifters, but it seems to run ok.thanks for replying

[muskrat]

temp gun made by raytech reseach it,it will help you with checking cyl head temp.stop running off hose you will not get a properly reading.try to fix one problem at a time.the first thing you should have done is make sure you have a healthly motor- compression.

[Goodoleboy]

I would try disconnectin the battery for a couple minutes. Then start engine and see if codes are cleared.To check temp of engine you can buy temp. heat check sticks (melt sticks) from auto parts stores.Heads should not exced 175 nor run cooler than 125 buy sticks accordingly.Make to marks on heads. The 125 should melt and the 175 should NOT.The telltale water is directly from water pump. It does not circulate thru thermostats.You can tell that its not going thru thermostats, Because it flows EMEDIENTLY on engine start up. If it had to waite for thermostats to open it would take a couple of minutes before you would see any water exiting.Telltale is a visual check only, to show that indeed your water pump is working. It does not indicate wheither or not water is circulating thru block.Shop manuals do say that to run a temp test on thermostats to use 80 degre water going to water pump. Abit inconvient for most folks in the back yard. I figure if mine runs cool and proper on the hose it will run good and proper on the river also.Good luck!

[jackman1939]

I just ordered the Raytec T4 temp gun for $55 - looks like it will do the job.Am going to buy a compression guage today and check out the compression on each cylinder.Will post results later.Will also try disconnecting the battery.thanks

[jackman1939]

Took the boat out on the lake today. Ran real good. After I brought it home, I checked the compression. Five cylinders were around 100psi, but cylinder (#3) was only 60psi. Don't know if this is much of a problem because it seems to run ok.Motor had good water streaming out the back, and the hot light did not come on. Still getting the error codes 41 and 43 for water temperature problems (this turns on the check engine light).Need to get that problem resolved.

[tahammes]

Check the #3 cylinder. You might have a ring stuck or the start of something worse. If your compression #'s vary more than 10% it could be time an overhaul. Good luck

[jackman1939]

Thanks. How do I check the #3 cylinder?

[muskrat]

well you all ready check compression,pull cylinder head check for damage..