Jump to content

running without the thermostat


flatback90

Recommended Posts

quite a few(me incuded) of us out here run our caburated 2 stroke outboards without thermostats and that got me wondering if it would do any harm to the general running of my 200tdi?? i think it doesnt matter on the two strokes because of the way they are lubricated but i have a suspicion that the oil in my 200tdi needs to be at a certain temperature to work properly?

Link to comment
Share on other sites

I've heard it said that the head needs the restriction of the stat to achieve water pressure in the head & prevent steam pockets forming. This can lead to hot spots and possibly cavitation damage. When I've suffered a dead stat and had to run without I've cut the centre out and refitted the remains to at least provide some restriction.

Link to comment
Share on other sites

I've heard it said that the head needs the restriction of the stat to achieve water pressure in the head & prevent steam pockets forming. This can lead to hot spots and possibly cavitation damage. When I've suffered a dead stat and had to run without I've cut the centre out and refitted the remains to at least provide some restriction.

Hi Fridge

You are spot on, thats why F1 engines are restricted to ( at one time) 3,5 bar coling system presure.

So one puts in the stat and make shure the system runs the right presure or more than recommended never less.

Kind regards

Ole

Link to comment
Share on other sites

I ran my defender 200 without a stat for a few months, i think i was experiencing other problems anyway at the time. However it doesnt prove to be a good idea as you end up recirculating hot water round a hot engine. particularly when working it real hard. It gets a chance to cool in the rad when the stat closes up.

Link to comment
Share on other sites

I ran my defender 200 without a stat for a few months, i think i was experiencing other problems anyway at the time. However it doesnt prove to be a good idea as you end up recirculating hot water round a hot engine. particularly when working it real hard. It gets a chance to cool in the rad when the stat closes up.

I thought that it was the other way around. It starts closed, so circulates the water around the engine until it is up to temperature - when it opens and releases the water to the radiator - allowing it to be cooled. Without a thermostat at all, it is just uncontrolled wide open, so will never really get up to a proper working temperature.

Link to comment
Share on other sites

I think the issue is that with no restriction, the water flows so quickly through the rad it doesn't get enough time to dump heat and hence, although it will be overcooled to start with, you have less cooling available if you manage to work it hard, at which point it may actually overheat faster.

Link to comment
Share on other sites

In my very humble opinion, I reckon that removing the thermostat will provide a choice to the waterflow, through the rad or recirculating through the engine (as if the thermostat were closed), so the waterflow will choose the easyest way, with overheating as a result.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy