Can I run my 1998 Johnson Ficht without thermostats?

[xyourobob]

After going many rounds with my overheating dilema the problem has been rectified with removing the thermostats. (some of you have been very helpful with advice, thankyou) Apparantly the water pump is not creating enough pressure to pop the thermostats out of their seats. Maybe my mechanic did not put the ugraded water pump in last week? Maybe the previous owner put different thermostat springs in? None the less my question is.........<br /><br />Is it safe to run without thermnostats?

 

[Solittle]

Re: Can I run my 1998 Johnson Ficht without thermostats?

It would have been helpful if you had put this with your other posts as I and others may have no clue on what has already transpired.<br /><br />Anyway - Yes you can run your motor without thermostats however johnny/rudes do not like to run well unless at normal operating temp. They usually due not idle well and may cut off when put in neutral. Then you go chasing that problem and upset something else. Best advice I could give you is to get it running the way they were designed to including the thermostats.<br /><br />By the way thermostats do not open due to pressure - they open due to temperature. I would take the rig back to your mechanic and ask/demand that he make it right - I assume the work was waranteed (if not you need a new mechanic).

 

[marinemech]

Re: Can I run my 1998 Johnson Ficht without thermostats?

its against the us e.p.a. laws really heavy fines if caught suggest you fix the problem and put thermostats back in

 

[xyourobob]

Re: Can I run my 1998 Johnson Ficht without thermostats?

SoLittle<br /><br />Thanks for your reply. This has been a process of elimination situation and my mechanic has been very helpful and AVAILABLE if you know what I mean. New water pump, sensors, gauge, checked x factor, obstructions on transum. I am told that on this motor the thermostats will operate properly when boat is idling around under 2000 rpms, when throttled above 2500 rpms the thermostats pop out of there seat and flood the heads with water, hence having the spring between the thermostat and the thermostat cover. Am I missing something?

 

[xyourobob]

Re: Can I run my 1998 Johnson Ficht without thermostats?

Thanks marinemech<br /><br />Now thats something else to think about. How come this fixed the problem? Could it be the springs in there are not springy enough?

 

[xyourobob]

Re: Can I run my 1998 Johnson Ficht without thermostats?

Hello?

 

[seahorse5]

Re: Can I run my 1998 Johnson Ficht without thermostats?

Also check the round rubber grommet seals that the tip of the thermostat seats on. They are mounted in the cylinder head and can distort is cases of a severe overheat. They then cause the thermostats not to move easily when the water pressure increases and they should move off their seats. Look at them thru the heads and make sure they are completely round, then with your fingers, insert a thermostat and pull it out, making sure there is no resistance.

 

[xyourobob]

Re: Can I run my 1998 Johnson Ficht without thermostats?

Is that rubber grommet inside the hole where the tip of the thermostat goes into or is it on the rim of the hole? As I can remember when I changed them, the part of the thernmostat that flairs out sits on the opening of the hole in the head, no rubber grommet was present on both sides. The springs appear to be new and rigid, like a lot of water pressure would be needed to push the thrermostat out of it's seat.

 

[seahorse5]

Re: Can I run my 1998 Johnson Ficht without thermostats?

You have to remove each cylinder head to replace the rubber grommets on your motor. It is mounted between the head and the block and it is where the narrow tip of the thermostat cartridge inserts and must move freely.

 

[xyourobob]

Re: Can I run my 1998 Johnson Ficht without thermostats?

anyone else want to give a shot on this topic? How about them springs?

 

[dick]

Re: Can I run my 1998 Johnson Ficht without thermostats?

Must be another problem ,those engine have great water flow and pressure. If the pump wasn't replaced do it ,If it was maybe a o-ring was left out in the pump assmbbly or the rubber ring at the base slid out or something .When does it over heat ? On muffs or in the water ? all the time or just at high speed ?

 

[Stumpys]

Re: Can I run my 1998 Johnson Ficht without thermostats?

Just for sh*ts and giggles...<br />I have seen folks put thermostats in backwards on cars, and this creates overheating problems like what your describing. I'm no expert on marine engines, so I'm not sure if they too can be put in backwards too.

 

[xyourobob]

Re: Can I run my 1998 Johnson Ficht without thermostats?

Thanks Richard.... The pump has been replaced by a mechanic with a good rep, I have used him for years. The problem is the same though. With the thermostats in, it idles at 160 degrees, if I rev it in nuetral the temp drops to 140 degrees. In motion at 2500 rpms the temp drops to 140 degrees, over 2500 rpms it shoots above 200 degrees and sometimes above and goes into slow mode. Without the thermostats at 5000 rpms it runs about 160 degrees. I checked the grommets the thermostats sit in and they are fine. I can only think the pump is not generating enough pressure to push the thermostats out of their seats? <br />And Stumpy, thanks for your input. These are like no thermostats you have ever seen before.<br />I was out today flying around the bay at 40 miles an hour without thermostats but I know I need to rectify the problem and get them back in. Anyone know a johnson mechanic with a traveling laptop/palm pilot in the annapolis area?

 

[clanton]

Re: Can I run my 1998 Johnson Ficht without thermostats?

Was the correct pump and housing installed?