Demise of the Robin...lots of smoke

[Marks481]

I think your gauge may be a little off. My gauge measures tank temp near the middle of the tank.

Your setup is definitely more accurate. My sender is just clamped in contact with the inlet to the hydraulic cooler, so I am getting some significant temp drops between the actual fluid temp and the sensor.

My concern about the CHT gauge would be running thermocouple lines through hose/wiring bundle at the pivot point. T/C wiring is not super robust and doesnt like being repeatedly flexed. Maybe stick it through some 3/8" hose to give it wear protection for most of it's run?

Again, nice job rivco. Do you still have any pictures of the headers inside the engine compartment? What size/wall thickness tubing did you use for the headers?

 

[Clarke]

The wiring through the tunnel is ordinary 16 ga stranded wire.

sg

 

[SnowRidge]

Aircraft Spruce and Specialty.

Westach Dual CHT gauges $75, Single CHT gauge $42-53. Thermocouples (with washers for spark plugs) are $18 each.

Tim, can you provide a link to the correct thermocouple? I can't tell which one it is.

Thanks.

Edit:

I think this is the one, with the 14MM ring.

I don't know much about thermocouples. Can an extension cable be used, or is the 48" supplied wire length critical?

 

[SnowRidge]

Tim,

IIMHO these high tmps on my machine are caused by a poorly designed high back pressure PT designed muffler.

sg

I know my machine ran too hot with that muffler. I'm pretty sure it contributed to the early failure at 110 hours. I replaced it with a stock Kohler muffler.

 

[ponytug]

You can use extensions, but they have to be with the appropriate thermocouple wire. Most thermocouple businesses will make you a custom cable, if you ask.

Thermocouple wire is solid, and not tolerant of repeated tight bends. I wouldn't worry about the flexing in the tunnel, as long as the cable had slack in it.

All the best,

Peter

Tim, can you provide a link to the correct thermocouple? I can't tell which one it is.

Thanks.

Edit:

I think this is the one, with the 14MM ring.

(Image removed)

I don't know much about thermocouples. Can an extension cable be used, or is the 48" supplied wire length critical?

 

[Marks481]

I think this is the one, with the 14MM ring.... Can an extension cable be used, or is the 48" supplied wire length critical?

Make sure you get the right size; measure your spark plug to make sure. This ring replaces the washer on your sparkplug, and the wrong one will allow exhaust gas to leak past the sparkplug. Aircraft Spruce sells three sizes (10/14/18 mm).

Here are the extension wires. The meters are calibrated for the voltage drop that occurs in a48" wire. Adding more T/C wire means less voltage reaches the meter, so the measured voltage is lower. The meter will have to be adjusted for the extra cable length.

EXTENSION LEADS from Aircraft Spruce

I would recommend hooking the instrument up and testing it with the tractor running before working on a permanent installation. The very low voltages generated by a T/C make the meter easily affected by electrical noise, so a quick test to make sure it plays well with the PT alternator would be a good idea.

 

[Marks481]

I think your gauge may be a little off. My gauge measures tank temp near the middle of the tank. Normal reading is 100 deg F above ambient. (eg. 50 outside/150 tank)

OK, I mowed today and ended up about 170F, so I guess my recollection was gone. THat matches about what you are getting. Guess that means that the temp gauge actually is worthwhile, since I really want to stay below 200F on hydraulic temp.

 

[gotago]

I just spoke with DJ of DJ's small engine repair. The repair is indeed a warranty repair, however as per a previous post, subaru/robin does not pay for removal and reinstall. DJ said that will cost about 40 bucks. I think that's a pretty reasonable price.

 

[SnowRidge]

$40 is amazing. Engine removal on the Robin equipped PTs must be vastly simpler than with the Kohlers, which have pumps on both ends and virtually no room to work.

 

[MossRoad]

Yeah, that seems like a very low price to pull the engine.