Curious and doubt this has been answered already.

[John H]

Ok I saw there is not 1 but 2 sizes of drain plugs. Now I ask WHY? I ask because a decade or so it appeared to only be one size. Is this for any specific reason like model variants or due to skid protection? Just curiousI as it seems odd. Does it mean you have to put a plug in from the inside and then another from the outside? I feel stupid here as this question just flat out seems stupid to even have to be asking.

[Mike]

Where do you see that there are two sizes of drain plugs, on your machine or when trying to order some?

[John H]

Well I got 2 bags and one says 3/4 and not sure what the other says as my daughter has lost the other on but it is smaller. I know they are both sold on the MAX parts site that is advertising in this site. Check and you will see.

[Rusty-Gunn]

Check your machine. It should be 3/4" size. Use the 3/4" plugs. Easy.

[xbunsenx]

I use 3/4" live well rubber expandable plugs on my Max IV.

[onefunzr2]

Sea Dog T Handle Brass Drain Plug 1" 520080 | eBay

I bought a pair of these 1" plugs and they fit my Max II. These are brass but they're also made in stainless steel.

[Noel Woods]

Funny this topic came up, most of the Max products I have seen (99%) at least use the 3/4" cap plug. However my 1995 Max 2 came with 1/2" cap plugs. I switched it over to the Argo style plastic drain plug system which was $8.00 or so for the Base and the plug, and the benefit of this is that the screw in plug is very neat, and has a t-shaped keeper that will retain the plug even when you loosen it to drain, I have lost a couple though when I forgot to screw them back in, so now drain them, then rescrew the plug, then carry on.

[Dozerlarry]

Sea Dog T Handle Brass Drain Plug 1" 520080 | eBay

I bought a pair of these 1" plugs and they fit my Max II. These are brass but they're also made in stainless steel.

just like the ones I use except instead of the T handles mine have nuts

[LW1911]

+1 I use Argo plugs as well

[hipowerone]

Interesting, as when bought my used MAX II, I was not sure of drain plug size, so max6x6.com sent me this part K-900 DRAIN PLUG KIT, SIZES 3/4" & 7/8" which has 4 each of 3/4" and 4 each of 7/8" plugs. I have since used the 3/4" plugs.