UREM37BY Spark Plugs

[hamer]

I’m due for new plugs and wanted to switch to the 37BY plugs by tempest. Currently my O290 has Champion REM40E plugs. Per all the documentation the 37BY is approved for my engine. However when I went to install today the wire terminal that screws into the top of the plug does not match with the 37BY, the thread is significantly larger.

Can I A) switch the screw caps without changing the wires? Or B) Is the Tempest UREM40E also the smaller thread? Is it a champion vs tempest thing? Or a 40E vs 37BY thing?

Any help would be appreciated, thanks.

 

[tyndall]

REM40E and REM37BY are the same 5/8” thread size (3/4 wrench). If your cap is bigger (7/8 wrench), then you have RHM40E plugs and they don’t make a RHM37BY.

 

[Tom-D]

You need to order the correct plug for your harness.
Do you even have the correct harness nut?
They can be changed but special tools are needed.

 

[hamer]

REM40E and REM37BY are the same 5/8” thread size (3/4 wrench). If your cap is bigger (7/8 wrench), then you have RHM40E plugs and they don’t make a RHM37BY.

Thank you, I think I mis-read my plugs, I must have seen ..40E and assumed, like an ass. Thanks for pointing that out.

You need to order the correct plug for your harness.
Do you even have the correct harness nut?
They can be changed but special tools are needed.

To be honest the harness is probably due for change as well (logs are a bit sketchy as to when they are due) and they are looking a little worn.

What's a good source for a new harness? I would prefer to run the 37BY with a new harness. The harnesses on ACS have mixed reviews.

 

[Tom-D]

Thank you, I think I mis-read my plugs, I must have seen ..40E and assumed, like an ass. Thanks for pointing that out.



To be honest the harness is probably due for change as well (logs are a bit sketchy as to when they are due) and they are looking a little worn.

What's a good source for a new harness? I would prefer to run the 37BY with a new harness. The harnesses on ACS have mixed reviews.

I don't do well with part numbers, I'd talk to the folks at Magneto services in Missoula Mt. They are the gurus.
https://www.aircraftmagnetoservice....MI-NXB_53A4wIVEarsCh1NjAPKEAAYASAAEgK71vD_BwE

 

[Tom-D]

Have the mag, make and model, engine numbers so they can look up the correct harness for you.

 

[hamer]

Have the mag, make and model, engine numbers so they can look up the correct harness for you.

Will do, thanks Tom.

 

[hamer]

I don't do well with part numbers, I'd talk to the folks at Magneto services in Missoula Mt. They are the gurus.
https://www.aircraftmagnetoservice....MI-NXB_53A4wIVEarsCh1NjAPKEAAYASAAEgK71vD_BwE

Just called, they are awesome. Thanks for that suggestion. They are setting me up with a new harness for the 37BYs.

 

[Tom-D]

Just called, they are awesome. Thanks for that suggestion. They are setting me up with a new harness for the 37BYs.

They are great folks, home run family business.

 

[hamer]

Now the real question is how many F-bombs I’m gonna drop trying to get this back cover off.

 

[flyingbrit]

Aren't the harnesses with larger nuts supposed to be more waterproof?

 

[sourdough44]

I ordered a few earlier this year with the wrong nut size. All has been corrected now. I had not looked closely enough.

 

[JAWS]

Can you swing the engine like a Cub or 185?

 

[hamer]

Can you swing the engine like a Cub or 185?

Good question, not sure. I was hoping I might be able to at least loosen up the mounts a little to get some more room.