TOPIC: Mid Range Jets?

On a page or two back, there was a thread about "115 Carbs". I apologize for not totally understanding, but hopefully one last explaination on how to disable the "mid range" jet subject will get thru my brain.

Without dragging this out,I have a 150, 3 carbs, and each carb has the jet on one side of the bowl. The otherside of the bowl has the fitting w/hose that goes into the block.

Remove the jet? Cut hose-plug the lines? Your info is appreciated! Mike

I plugged the small pipe that runs across the top of the carb to disable mine, although plenty say you can just remove the pipe. I wasn't happy about this as it seemed to me the carb would be sucking too much air mid range with it open to atmosphere. Thats just my theory - motor seems to run fine now though although I did other work at the same time (had a big flat spot before).

My two bobs worth.

Geoff UK

You'd want to remove the float bowl vent jets as well.

My thoughts exactly on plugging up the vent tubes, you're trying to prevent the fuel mix from leaning-out too much anyway, so why leave an intentional air leak in the carb??!

HTH.........ed

thanx for the replies! I have cut and plugged the hoses on mine also. Now I will go back and remove the metering jets.

By the way, if it is a Merc 1500 it should have WMK 14 carbs on it, which do not have the back drag tubes. If you have different carbs they will work fine, just make sure you have the correct size main jets in them for the 150. Another way to deal with the tube is to put a "bb" in it and re connect the tube.

Why do you need to remove the jets if the tube is blocked? They only act as vents for the float bowl now which of course you must have. If you remove the jet itself then you will have a big (ish) hole in the carb which can allow dirt & water in, it seems to me. Or have I got it wrong? Mine runs fine with the old jets still in place.

I am not sure about the jet removal myself!! Some of the best say to take them out, but as you stated, it just creates a bigger hole. That may be what it needs to allow the floats to float and keep the bowl full. I did the plug in the lines and removed the jets, all seems to be well. It will suck 6 gallons out of the tank pretty fast when running hard!