Slip Knot, need you expertise on My 850 Ford overheating

[walrus]

I've thrown the parts cannon at it, New Radiator, New TStat, New Water pump, Hoses. Knocked out frost plugs to flush block, there was nothing in it, to speak of anyway. Was bush hogging yesterday and it was getting hot so I stopped, watched temps really rise once I stopped, used starter to turn engine over with key off, temps went down again but then right back up once I stopped. Could there be air in the head? that I haven't got bled out?  I have a shroud but its not on, its never had one and I never had this issue until a 4 or 5 years ago.
I think I've asked your help on this before. The parts I'm getting are China made reproductions so Tstat or whatever could be bad I suppose? What say you?

[oldnslo]

Start with a true temperature reading with a secondary measurement device.

[Matt_T]

Agreed on checking temperature. If it is definitely running hot pull the plugs and see if they look lean. That'll cause a motor to run HOT.

[slip knot]

Sounds like you've already covered the easy stuff. Double check the temp reading. I like to use a IR gun on it. quick and easy.

Those heads were problematic about getting hot and cracking but I don't think that's your problem. I would check the carb for leaning out and also check the timing. I had a problem with the advance weights hanging up and the timing being way off. Belt tight?  Did the Tstat come from a reputable place or a TSC? May need to check it for proper operation too.

[walrus]

I put a new gauge in it, before I did I stuck it in boiling water to see where 212 actually was. I'm confident the gauge is ok.  I don't see any white smoke, no antifreeze in oil. TStat came from some tractor place online. Whats a reputable Tstat?  Carb could be leaning out, Timing is on flywheel? under that little sliding door?  Tractor runs great. Starts right up, winter or summer . Doesn't over heat plowing snow or it didn't last winter. The summer heat is when I have the issue

[Rusty]

Radiator getting good air flow? I've had to stop and clean crud from them after an hour or so of Bush hogging.

My little TYM built RK plugs up fast when there's thistle in the field.

[slip knot]

yeah the timing marks are on the flywheel behind the little door. kinda hard to see. I usually mark it with chalk then throw the timing light on it.

if it was overheating prior to the Tstat replacement it may not be an issue. The Tisco parts are problematic. I get most parts from Napa and they seem to be a bit better. a 180 Tstat is pretty generic.

is the fan a pusher or puller? put your hand on the grill and see if you feel a pulling or pushing of air. My 860 with a 3 blade puller has no problems keeping cool in S.Tx with a shroud. You probably want a puller. If you got a pusher you need to blow it out backwards.
Keep the old radiator and have it cleaned and flushed its 10X better than any radiator you'll buy today.

Try running it without a radiator cap and observe the flow thru the radiator is it a good flow and do you see any bubbles? You could have a bad head gasket letting compression into the coolant?

These old machines are pretty basic. Dont overthink it. 

[walrus]

Fan pulls air thru radiator, need that in winter up here.   Think I'll take it apart today see if I can get shroud fit in there. NAPA not open today but can get Tstat tomorrow. I'll run without Tstat and see what happens.

[Snaparxon]

What happened or what were you doing with the tractor when it originally started to have this problem 4 or 5 years ago?

[walrus]

What happened or what were you doing with the tractor when it originally started to have this problem 4 or 5 years ago?

Nothing unusual, just noticed it running hot when bush hogging. We used to hay with this tractor with no problems.

[Crispycritter]

Gas or diesel?

[walrus]

Gas or diesel?

Gas, 172 cu in

[highland512]

I would check the radiator out as well. After all these years of use and hard work many of the old tractors have chafe build up on the outside and who knows what on the inside.

[Snaparxon]

What happened or what were you doing with the tractor when it originally started to have this problem 4 or 5 years ago?

Nothing unusual, just noticed it running hot when bush hogging. We used to hay with this tractor with no problems.

Any work been done on the engine months or weeks prior to the first time it ran hot?

[walrus]

What happened or what were you doing with the tractor when it originally started to have this problem 4 or 5 years ago?

Nothing unusual, just noticed it running hot when bush hogging. We used to hay with this tractor with no problems.

Any work been done on the engine months or weeks prior to the first time it ran hot?

I did engine way back when we had to use it for the farm. Probably in the mid 90s. Never had an issue until 4 or 5 years. The only thing I can think of is carb, needle and seat a victim of E10 gas. Replaced them so maybe its leaned out now? I have whole front of tractor off now. Fan belt is cracked so got that coming. Talk about a pain in the ass. Tractor has front pump for front end loader, getting the belt requires pump come off, splined shaft is beated up, coupling had bolts seized. 120 bucks to replace parts once I destroyed them getting it apart. Never seize is going on every thing on way back.
If I could post pics without a hassle I 'd post them