245/260 Carbs

[SS170]

Anyone have experience with a carbureted 245/260? Doing a build and not quite sure which carbs to use. Specs say WMH-X. Don’t have the $$ to go injection so that’s why the carbs. Thanks.

[rjdubiel]

I used WH series carbs from 2.4 on my 2.5 245. WH20, 31, 46. All about the same seat of the pants feel for me. Start with mid 80's for main jets and work your way down, low 82-84 seems to be safe for river, 78 for drags is lowest I went. 56 air jets to lean out the idle. Remember these are two circuit carbs so no mid range jet really. If you get tuning on the line just do not hold the throttle at half throttle for a long time, lean spot there with those carbs. The WMH are three circuit so they have a midrange jet.

The WH carbs work very well on a 2.5 in my opinion, find the throttle cam and push rod off a 2.4 200 and you are good to go as they are different than the WMH throttle linkage and cam.

[tlwjkw]

The WH carbs work very well on a 2.5 in my opinion, find the throttle cam and push rod off a 2.4 200 and you are good to go as they are different than the WMH throttle linkage and cam.

True....

wmh's from any of tha 175/200's (bodies and internals 'bout tha same on all of 'em) will work when ya jet them for tha 245... don't remember exactly what size jets they were but i'm sure someone on here has a chart and/or a lot younger memory than me......

[rjdubiel]

I think they have both jetting for WHM with pumpers and without pumpers. I will take a look if I remember when I get home!

[SS170]

From what I’m gathering, the WH’s are easier to tune but have the lean spot at mid throttle due to their 2 circuit design. The WMH are safer due to their 3 circuit design but are a little more complicated. What about WMVs ? Aren’t they a 3 circuit design also? This is the black magic area of Mercury. Thanks for your help.

[tlwjkw]

first ('91) had pumps then they went away.. all jetted same.... 245 may have went away when tha wmv's came around from mother merc... never ran wmv's on one but they should act tha same as tha wmh's with jetting...........jmo.