Fitting New Jets - Mercury V6

[Silversurfer]

Hi has anyone got a diagram on how to fit new fuel jets to a mercury XR2 please. A step by step scan would be great!

Thanks in advance!

 

[JamesM]

You take the old ones out and then fit the new ones back in where the old ones came out of.

There will be a brass hex shaped screw head (1/2" I think) with a groove for a flat head screwdriver on each side of the carb towards the bottom. Unscrew it, fuel will piss out everywhere untill the bowl has drained. Depending on what carbs you have the jet will either be in the end of the assembly that you have just removed or down in the hole that you took it out off. The jets then just unscrew with a flat head screwdriver. As you unscrew them they always seem to get more difficult to turn when they're about half way out then they ease of again, mine did anyway. Dont know why this is, maybe to stop em falling out if the come loose.

 

[Silversurfer]

Cheers Johnny still not even sure where the old ones are the located though hence the post! Do i have to remove the airbox on the front of the engine? Anyone got any pics?!

 

[Cookee]

There are at least 2 different carbs that I know of, so you'll need to put up photos of yours first - without airbox would be best!

 

[Burty]

wh-20 carbs, jets are circled. 3 more on other side

 

[JamesM]

Burty those are wh-22's I have wh-20's on mine.

Jets are roughly in this area and look like this on pretty much all merc carbs. If when you undo it fuel doesn't come out then you have removed the idle jet. Idle jet on the above pic is the smaller brass hex head at the top of the carb above the circled one and is an air jet hence no fuel.

 

[Burty]

Burty those are wh-22's

o well they is better than 20's cus its a higher number

 

[JamesM]

The flywheel cover in that photo above looks OK dun it

 

[Silversurfer]

Cheers guys very helpful as always. Thanks for the pointers will take a photo anyways when I get down there again.

 

[Taz]

And if they dnt fit cross thread them in!

 

[Silversurfer]

Mines slightly different so i guess its wh-20s' is that an earlier or later carb and which is better?

 

[Burty]

Think they are as good as each other but JBD will know, pretty sure the 20's and 22's jets are in same place though

 

[JamesM]

There are at least 2 different carbs that I know of

Mines slightly different so i guess its wh-20s' is that an earlier or later carb and which is better?

There two styles of merc carbs the old dual bowl carbs as shown in Burty's photos and the newer single bowl pumper carbs. The older XR2's will have the earlier dual bowl and the later ones will have the pumper carbs. However there are many different models of each type for example WH-15's, WH-20's, WH-22's, WH-31's (and others I cant remember) are all dual bowl carbs and look much the same. If yours look different then they will be one of the many different models of pumper carbs, WMH-17's for example.

As for which type is better, the older dual bowl carbs are less complex than pumper type carbs and easier to jet. Some people prefer them because of this and also because the pumper carbs pump fuel into the venturi when you step on the throttle and this can cause them to bog down a bit out of the hole, bad for skiers. I think Cye used to run the older dual bowl carbs on his XR2's.

And one last thing WH-20's are older than 22's (only by one year) but had bigger venturi's so were a better power maker than the 22's. However the 22's had a better idle and easier starting so were more user freindly, the later carbs were even better again in these area's. But for out right go and if you dont mind a lumpy idle the good old WH-20's (big bore's) remained the best top end power maker

 

[Silversurfer]

Sh*t you know your stuff! Cheers
Still not sure which ones I have will take some photos when i swap the jets this weekend

Thanks again

 

[Silversurfer]

Fitted the jets and ran it up on the hose all seems ok. However is it normal for cooling water to come out of the prop as well as the water jets though dont think it did this before. I know this isnt related to chnaging the fuel jets before anyone says so.

Thanks for your help

 

[Burty]

Yes

 

[JamesM]

The water that runs out of the prop is the water that runs down through the mid section in order to keep it cool. So yes its normal.

 

[Silversurfer]

Nice hadnt noticed it before!