115 carbs can i switch positons

[ragu]

Hi I recently purchased 3 carbs for my 115 merc 1970 model. The carbs "look" to be in good shape but i was going to rebuild them and just switch them with the ones on my motor now or should i rebuild the ones that are on my motor also they all appear the same do they have to be put back on in the order like top middle bottom looks pretty simple to rebuild them anything i should pay special attention to i do have the seloc book but experience is the best teacher any help would be great

 

[Silvertip]

Re: 115 carbs can i switch positons

They need to go back in their original positions. Because the carbs "look" the same does not mean they are. Thottle bores, jetting, and linkage can be different. You need to check the part numbers stamped into the carbs and compare them. If there is nothing wrong with the original carbs, why not rebuild them and prevent the possibility of ruining your engine because the replacement carbs were jetted leaner and you holed a piston as a result.

 

[Laddies]

Re: 115 carbs can i switch positons

There is no differance in jetting position to position, year to year there are 5 differant main jets being used and a few differant carb types. In 1970 they call for .066, in 72 they were changed to 68, in 75 to .072, in 79 to .074 and in 86 to .076 so you need to ck carb year and type to get your jetting right if you aren't useing original carbs

 

[ragu]

Re: 115 carbs can i switch positons

ok sounds good the numbers on the carbs are the same and i know the motor they came off of is the same year as mine so if i order a rebuild kit and rebuild them i should be able to put them on mine right i really didnt want to try to rebuild the ones that are on there now in case i screw something up atleast i can put the old ones back on althoug in the book it looks very simple and i tore one apart not much in one thats for sure