20/25hp 2 stroke merc carb difference

[boater1234]

Ok,here we go on this carb issue i have.I have a 1993 20hp 2 stroke merc with the original carb of course which states the number 32 on it.I look at the 3 different carb numbers online and there is WMC 31/32A and plain 32.

All 3 carbs seem no different as in what the schematic shows,i mean no difference.So i upgraded from the 20hp carb to the 25hp carb,the yrs were almost the same,the used carb i got was from a 94 and my carb was from a 93 but i mean they are 100% identical except for the bigger bore for more power but here is what i noticed.The 20hp carb i have says it's a 32 and the carb i just got says it's a 31A but they are 100% identical from what i can see.My question is what is the difference between the 32 and 31A if they look i mean identical besides the size of the bore.I called the place i was going to buy a new carb from and all 3 numbers come back to the same schematic which shows the parts to be identical so what's with the number difference?

 

[flyingscott]

Don't worry about it. If you looked up how many different carb#s there are for that motor over the years it would astound you.

 

[boater1234]

I called the maker of the WMC carbs and he said all I need to do is swap them out and you should be good to go as he looked all 3 up for me and explained it could just be a minor thing they do to them that changes the number but they should still work. I have another forum I go on to and one of the guys said I have to redo the timing but I asked the guy and he said you don't need to do anything but swap them out and you should see a power difference more than anything, maybe a bit more wot speed he said but don't expect but a few mph at best which I figured.

 

[flyingscott]

That is right. Not a good idea to play with timing on that motor as the 20/25 have the same for timing. I have made that conversion a bunch of times.

 

[boater1234]

Awesome, so I'm rebuilding the carb today and I'm going to test how it works next week, can't wait. Ty for the great info. I will post how it comes out.