Which carbs on inline six

[1954bmw]

Quick question for the inline gurus, I have a 1971 115 Mercury short shaft on a little MX-14 Checkmate, I also have a 1971 135 Merc and a ? 150 Merc with distributor, for best power and performance, which would be the best carbs to use on the 115???? Thanks, Mark

[creeljd]

I think they're gonna tell you that depending on the horsepower, different in-line 6 motors not only have different carbs but different port timing inside the motor.

[99fxst99]

Quick question for the inline gurus, I have a 1971 115 Mercury short shaft on a little MX-14 Checkmate, I also have a 1971 135 Merc and a ? 150 Merc with distributor, for best power and performance, which would be the best carbs to use on the 115???? Thanks, Mark

Cool! let's see some pics of the boat!

[creeljd]

Cool! let's see some pics of the boat!

Yes, I would also like to see those MX-14 pics with the 15" motor. I've always loved the look of a short shaft in-line 6 Merc.

[largecar91]

I think the carbs were the difference between a 71 115 and 135

[Dave S]

and reed opens.......stops. carbs had bigger venturies inserts.... less flow.

[1954bmw]

I thought the reed stops were twice as big on the 135, something like 5/16 versus 5/32??? Are you saying the 115 carbs have less flow??

[Dave S]

I belive so...... many years ago. Think 115 had big blobs of plastic to cut the area. Early 115 and 135 blocks were the same....

[largecar91]

They use different carbs. Not sure if venturi size is different but they are different part #'s

[boatman14544]

just swapping the carbs on the 115 is going to be more problems than it is worth. The only difference between the 115 and the 135 are the carbs and reed stops. The 115 is a choked down 135. There are no other differences. The 150 is a totally different animal. Here are a couple of pictures of the carb throats to see the difference, the 115 has the venture restrictor in it and is also jetted quite a bit smaller. 1350 carb on the left.

[Zonkercraft]

just swapping the carbs on the 115 is going to be more problems than it is worth. The only difference between the 115 and the 135 are the carbs and reed stops. The 115 is a choked down 135. There are no other differences. The 150 is a totally different animal. Here are a couple of pictures of the carb throats to see the difference, the 115 has the venture restrictor in it and is also jetted quite a bit smaller. 1350 carb on the left.

The 115 reed cages have less ports in them than the 135 140 motors, along with the carb differences. No, it's just not worth the trouble to switch the carbs out. You're much better off switching to the 135 140 powerhead. The 150 won't fit the early midsection. Just my thoughts, here