1984 Mariner 40 Upgrade Questions

**forgotten** · 12-13-2020, 12:41 PM

I have a 1984 Mariner 40E 6E9. I have seen one or two very short bits of information saying the only difference between the the old yamaha/mariner 40hp and 50hp was the carburetors , but I can't find any information that says yes or no. What are the differences between the 40 and 50? Would it be possible to swap a few parts the change it to a 50?

Also I'm thinking about changing the prop. It currently has a 73136a45 which is a 10-3/8x13 and im trying to decide between a 14 or 15 pitch to try for a little more top end. Im leaning to the 14, but any options and opinions are helpful.

PS. It is on a 1983 Fisher 16' flat bottom.

**Capt.Insane-o** · 12-18-2020, 07:35 PM

Look in the yamaha parts schematics for those years, same motors.

**forgotten** · 12-18-2020, 09:21 PM

Ok. So the 40hp carb part number is 6H4-14301-06-00 and the 50hp carb part number is 6H5-14301-06-00. This is the only difference I can find. Ill start looking for the set then.

And any opinions on prop pitch changes are use full

**David - WI** · 12-18-2020, 09:46 PM

Originally Posted by forgotten

Ok. So the 40hp carb part number is 6H4-14301-06-00 and the 50hp carb part number is 6H5-14301-06-00. This is the only difference I can find. Ill start looking for the set then.

And any opinions on prop pitch changes are use full

Bunch on eBay now. https://www.ebay.com/i/224243822784?...brand%3DYamaha

**forgotten** · 12-18-2020, 10:18 PM

Originally Posted by David - WI

Bunch on eBay now. https://www.ebay.com/i/224243822784?...brand%3DYamaha

I did look at that one, but the bearing in the bottom one is bad. I am about to order one tomorrow for $160.

**SS Minnow** · 12-18-2020, 11:31 PM

Originally Posted by forgotten

Ok. So the 40hp carb part number is 6H4-14301-06-00 and the 50hp carb part number is 6H5-14301-06-00. This is the only difference I can find. Ill start looking for the set then.

And any opinions on prop pitch changes are use full

Not enough info to really advise on any type of prop. Some useful info:

What rpm and speeds are you seeing now with the current prop?

Where is your prop shaft in relation to the bottom of the boat? Even with it, inch lower then it? Two inches lower then it?

ETA, Ebay Craigslist and Facebook Marketplace are great for finding used props for your boat. Most of us here have multiple props for our boats bought either trying to find the right one or in my case I have three props that I use for different application but I have 8 or so props total that were bought trying to find the right one(s). I need to get around to selling the ones I do not use, but I have more important things to do, I guess.

**David - WI** · 12-19-2020, 09:23 AM

Originally Posted by forgotten

I did look at that one, but the bearing in the bottom one is bad. I am about to order one tomorrow for $160.

The bearing in the engine failed so he's selling the good parts off the motor according to the description.

**forgotten** · 12-19-2020, 10:41 AM

woops. I'll probably go with that one then.

As for prop I am going to wait until I swap the carbs and test it to decide.

**forgotten** · 12-19-2020, 11:07 AM

It is a good thing I waited to check again. My mariner is a 2 cylinder not the 3 cylinder that those parts are for. well back to digging through parts diagrams.

**forgotten** · 12-19-2020, 11:18 AM

the numbers I pulled off my carbs are (ub24 6E900) when I try to search for these I get taken to the 40 ELO instead of the EL that I thought it was. when I look at the 50 ELO it has a different style carb and has auto blend.