hey guys i need a quick response as i found a mc28 servo motor online and was thinking about bidding on it so here it is are the mc21 and mc28 servo motors interchangeable? i just want to make sure before i throw money on something i wont be able to use... thanks would be grateful for a quick response

Why not check the parts catalogue on the main part of the site to see if the part numbers are the same?

I did but what do the numbers mean like on the model for 7L 31420-kv3-831 it has a number 1 on it and for the 9L it has a 31420-kv3-680 and has a 1 on all models except in a 7L does that mean your able to use any besides if it has a number 1 it ? Sorry if I'm being confusing since I am confused myself

All MC28's use "1" of part number 31420-KV3-680 as the power valve servo motor. So thats pretty easy to understand.

Now when it comes to the MC21, it does indeed look pretty confusing.
There are 2 different part numbers: 31420-KV3-831 and 31420-KV3-680.
31420-KV3-831 comes in type blank and type J
31420-KV3-680 comes in type blank, type J, and type 3J.

I have no idea what the "type" indicates. Be it blank, J or 3J. I would guess it is a subtle difference due to slight design changes over time to improve cost or performance or ease of manufacture. So I would just tend to ignore the "type" categorisation. Maybe this is silly? Someone please correct me if I am wrong.

It appears that the MC28 servo (31420-KV3-680) does indeed work on all models of MC21 as there is a "1" shown at the intersection of that part number and all models of MC21. (disregarding "type")

Please note that I am just making all this up from looking at the Parts Manual and have not physically tried this.
I hope that dilutes the confusion for you a bit?
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[color=#808080][size=9]Yes,.. I too know how to waste Time and Money,...

All MC21 servo motors are the same, BUT. There are two types.

The only difference is that two of the pins in the main electrical connector are reversed.

If you connect the wrong servo to the wrong harness the servo will either not work, or blow the PGM up. Honda soon changed this back.
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If I have to take the carbs off once more...

hey tucker ya kinda figured the 1 was 1 of that part number...

what i did find confusing was the 2 different part numbers and also the types

so like you said it does seem the 28 servo motors work on the 21's i am thinking of getting the one i found and disregarding the type hopefully the different types dont have any differences at all

but thanks for clearing things up for me

input on the types would be great