Welch plug sealing

[jammer777]

hey guys!

so i rebuilt both carbs and only changed the welch plugs on the upper carb on my 1975 115 evinrude v4 two carb engine, i have fuel streaming out of the carb when trying to start the motor, I think it might be the welch plugs, and have one spare one left from my carb kit that im going to redo,and im going to tear out one of the old ones and repunch it in there, currently the plugs look seated pretty good with not really any gaps and i dont think i could get them out without putting a punch through it and tearing it out. it could also be the float assembly causing my leak, but i have a new needle in there and valve and all that and no obstructions and it seems be working fine.

So couple questions about the welch plugs and sealing them

1. i see the clear nail polish method keeps coming up for suggestions, sounds like it holds up, but is that something that needs to be put in the carb housing prior to flattening out the domed welch plugs? or can one topically brush it on afterwards around the edge of the welch plugs?

2. Any other preferred sealants out there? currently i just flattened out the welch plugs in the carb housing with no sealant

3. with a generous amount of fuel leaking from the carb when trying to start (without priming the bulb) and streaming down the front carb/airbox past the choke plates would one think that would be the welch plugs (that appear to be seated properly) or would one think that would more likely be something not working right with the float and the needle assembly?

4. Also i noticed one of the jets was a few turns loose when removing the screw, could that be the source of fuel pouring out the front of the carb when trying to start?

thanks as always guys! love this place!

 

[Cap'nHandy]

Im gonna lay my bets on the float adjustment, and the needle and seat not sealing properly. Fuel streaming out sounds like fuel pump is pumping, and the carb bowls fill up, and then fuel flows out cause the needle / seat does not stop fuel flow.

If the needle does not completely seat when the fuel bowl is full, that will food like you mention. Think about the size of the leak, compared to the possible size of the leak from a poorly seated plug. A poorly seated plug is still a SMALL amount of space for the fuel to flow from. Without seeing the leak, its hard to say, but methinks its the float adjustment. When the float is almost level ( full bowl position ) the needle should be firmly seated. Adjust the tab. THen when the bowl is almost empty, there should be lots of fuel flow, and the measurements are to get you ball park. You still need a good seal when full, and good flow when it starts to empty. Hope that helps.

Blaine

 

[emdsapmgr]

Agree with Captain. The welch plugs do need to be sealed when installed. Bombardier sells a product called Gasoila that will work. Sold in a small can, part number: 200763. It dries quickly and is impervious to gasoline. While some fuel may leak from around an unsealed plug, it is probably not the sole reason for your current problem. All jets need to be snugly seated in their bore.

 

[jammer777]

awesome thanks guys! i really appreciate the responses, im going to concentrate on the float adjustments first here and see if i can find Gasiolla at my marine distributor here and get this thing running right!

 

[Tim Frank]

I'd bet on the float valve and/or seat. what happens if you pump the primer bulb several times ? Same thing?

This is a similar thread to one from a while ago on this topic.
http://forums.iboats.com/forum/engi...evinrude-outboards/494521-sealing-welch-plugs

None of my OEM manuals fuss about sealing welch plugs.....I think it is probably one of those "can't do any harm, but not necessary if done right the first time" bits of overkill that most of us do on occasion. Kind of like sealant on a head gasket.

 

[jammer777]

awesome thanks guys!

 

[jammer777]

haha thanks Tim! appreciate it! i remember coming across that thread in my searches as i remembered the peeing in the Mississippi comments haha!! its the same thing i do the primer bulb for sure

 

[jammer777]

hey guys! sorry for the late reply but i though id post an update, so between sealing the welch plugs with clear nail polish and resetting the float valve height, its been starting up really nice, and running perfect which has been really for the last couple weekends of summer here, I wanted to thank you guys for all the help, i think i got my startup procedure figured out here now that things seem to starting right!