Temp Sensor

[Greg Field]

I've been getting pretty shitty mileage lately, so I decided to see if the temp sensor was actually making contact woth the metal base of the plastice sensor holder. (If it doesn't make contact, it will never read the temp accurately.)

 

So, I put a wrench on the holder and attempted to take it off the head. It just crumbled when I twisted the wrench. What a cheap POS!

 

Fortunately, I had the solid-brass replacement in waiting.

 

 

This photo shows the crumbled plastic holder, the sensor, and the replacement brass holder.

 

The next challenge was getting the metal base out of the head. Its hex portion was actually recessed into the head casting. To get it out, I had to grind the tip and side of a 15-mm deep-well socket. It was really in there, glued on with some type of loctite.

 

 

Then, I did a trial fitting after smearing the sensor with antisieze to leave witness marks as evidence that it had bottomed out in the holder. No surprise, it didn't bottom out, and there was no way to make it bottom out without a lot of milling work. Instead, I cheated, and filled the recess with antisieze, which should do a good job of transering heat between the holder and sensor.

 

It seemed to me that the system would work best if it transfered heat between the holder and sensor, without the holder radiating too much heat away from the sensor, so I decided to insulate the holder with several layer of duct tape, as shown below:

 

 

 

Then, I antisiezed the threads of the holder, and cinched it tight into the cylinder head. We'll see if it does anything positive other than getting rid of the cheap POS sensor holder . . .

[jrt]

I can't really tell from the images, but does the cheap POS temp sensor make contact with the head or is it too short as well?

[dlaing]

Fortunately, I had the solid-brass replacement in waiting.

 

 

92615[/snapback]

I have been waiting weeks for my plastic replacement.

Do you have a brass one still in stock?

I'll buy it!

if you can approach the $29.95 price here http://www.mgcycle.com/electrical.html

I am tired of not riding

And let it be a warning to everyone, that plastic will break from just hand tightening it too tight.

[Greg Field]

I've sold probably ten in the last month. Moto Guzzi US is out of them, Teo's out of them, and Ago, too, last I checked. I have more on backorder, but you know how long that can take . . .

[Dan M]

I've sold probably ten in the last month. Moto Guzzi US is out of them, Teo's out of them, and Ago, too, last I checked. I have more on backorder, but you know how long that can take . . .

92630[/snapback]

 

 

Gerg,

 

Do you know of any value chart for this sensor?

(various temperatures & corresponding ohms) It would be nice to be able to check accuracy.

 

Dan

[guzzi323]

I have been waiting weeks for my plastic replacement.

Do you have a brass one still in stock?

I'll buy it!

if you can approach the $29.95 price here http://www.mgcycle.com/electrical.html

 

Damn my local dealer had it in stock but it was $52. I guess I should be happy they had it at all, eh?

 

johnk

[richard100t]

Has anyone tried a hardware or plumbing store for the brass fitting? You may well get a suitable piece for far less.

[slug]

Has anyone tried a hardware or plumbing store for the brass fitting? You may well get a suitable piece for far less.

92645[/snapback]

 

Metric threads?

[jrt]

I'd look at McMaster.

[badmotogoozer]

I've been getting pretty shitty mileage lately, so I decided to see if the temp sensor was actually making contact woth the metal base of the plastice sensor holder. (If it doesn't make contact, it will never read the temp accurately.)

 

 

Hmmmm... I wonder if this might have something to do with my horrendous mileage (22-24 mpg). All my idiot dealer did was mess up the carbs trying to lean it out. I doubt this would have occurred to them. I never thought of it either.

 

Put that on the massive list of things to do/check. <_>

 

Rj

[Guest ratchethack]

All my idiot dealer did was mess up the carbs trying to lean it out. 

Find a new dealer, Ryan.

 

Ain't no carbs on it. . . . .

[badmotogoozer]

I'm too lazy to type out "throttle bodies" when "carbs" gets the job done. It's all relative ...

 

No new dealer - I'll be taking care of everything from now on. I'm just not real happy about having another project bike.

 

Rj

[dlaing]

I can't really tell from the images, but does the cheap POS temp sensor make contact with the head or is it too short as well?

92622[/snapback]

Probably only on the bikes that get good gas mileage.

Mine was loose, so I suspect it could have contributed to bad gas mileage, especially in cooler weather.

Some angel on the forum hooked me up with a brass one.

Now to get the old one out...

[Kiwi Dave]

Gerg,

 

Do you know of any value chart for this sensor?

(various temperatures & corresponding ohms) It would be nice to be able to check accuracy.

 

Dan

92635[/snapback]

 

I have a pdf page showing the resistance/temperature tracking for the older models (P8 CPU) if you're interested. I imagine they would be fairly similar. But having said that, why would they change 'em?

 

PM me if you want me to email the pdf.

[dlaing]

Now to get the old one out...

92893[/snapback]

I pounded the flat blade screwdriver into the hole of the (copper???)housing till it bottomed out and then some, then I whacked it with the impact driver.

I was lucky the impact screwdriver wedged in pretty good and the housing was fairly loose but the locktite made it a small fight for several rotations.

 

I am a little paranoid that they switched from brass to plastic to insulate the sensor from overheating, so I intend on using a fair amount of teflon tape to insulate it a little.

Since I have tuneboy, I was planning on tweaking the engine temperature map, anyway.

 

PS If I cannot cancel the order for the plastic sensor housing, I may have one for sale, if it ever gets here.