Evinrude carb screws?

[chubcobear]

I have rebuilt several outboard carbs, but I have never run across so many boogered up carb screw heads as I have on this '69 Evinude 25902D 25hp. I have access to stainless screw stock and can (should) I use SS screws to substitute for these boogered screws. Dis-similar metals? Other reasons not to? Hope it isn't a dumb question, but I just wasn't sure if it was a good idea. Thanks.

 

[Chris1956]

Re: Evinrude carb screws?

Normally there is enough oil to keep the screws from rusting. SS and Aluminum do not get a long very well in a salt environment. I would stick with steel screws.

 

[kfa4303]

Re: Evinrude carb screws?

I'm gonna have to respectfully disagree with Chris1956. SS is about the only/best dissimilar metal you can mix with aluminum. All of the stock bolts in the LU of your motor are SS and they're threaded into the aluminum exhaust chamber and almost never cause a problem. The only reason people don't use SS more, is the cost, but that doesn't sound like an issue for you. In fact, SS is the only type of hardware you should/can be used in a marine environment. Don't believe me? Ask my fellow aluminum boat owners here in the forums. SS is the only hardware we use on our tinnies precisely because it will not have a galvanic reaction with the aluminum hull. Steel is a definitely a no-no and will rust in no time. Stick with aluminum rivets and/or SS for all your hardware needs in your boat, regardless of whether you are in fresh or salt water. Of course, you could always try to find a donor carb and salvage the hardware from it, but that may be more trouble than it's worth.

 

[Tim Frank]

Re: Evinrude carb screws?

I'm gonna have to respectfully disagree with Chris1956. SS is about the only/best dissimilar metal you can mix with aluminum. All of the stock bolts in the LU of your motor are SS and they're threaded into the aluminum exhaust chamber and almost never cause a problem. The only reason people don't use SS more, is the cost, but that doesn't sound like an issue for you. In fact, SS is the only type of hardware you should/can be used in a marine environment. Don't believe me? Ask my fellow aluminum boat owners here in the forums. SS is the only hardware we use on our tinnies precisely because it will not have a galvanic reaction with the aluminum hull. Steel is a definitely a no-no and will rust in no time. Stick with aluminum rivets and/or SS for all your hardware needs in your boat, regardless of whether you are in fresh or salt water. Of course, you could always try to find a donor carb and salvage the hardware from it, but that may be more trouble than it's worth.

I'm with Chris.
If you check the galvanic corrosion series, you will find many better combos than SS and Al.....in fact there aren't many that are worse. Why not stick with the original type of fastener?
When you say that the heads are messed up, are you looking for SS to be a harder option and not get chewed up?....or are you talking about the brass jet-needles?

 

[Daviet]

Re: Evinrude carb screws?

I'll throw in my 2 cents worth, use stainless steel. I have seen what happens when you use regular steel screws in a salt water enviornment.
I have seen carb screws that a magnet will not pick up, I assumed that they were stainless steel.
You could order the oem screws, that would take care of all the guess work.

 

[boobie]

Re: Evinrude carb screws?

Stick with the OEM screws. Hopefully they know what they're doing.

 

[Tim Frank]

Re: Evinrude carb screws?

I'll throw in my 2 cents worth, use stainless steel. I have seen what happens when you use regular steel screws in a salt water enviornment.

OP is from "Central Arkansas".

 

[Haffiman]

Re: Evinrude carb screws?

'SS' is not just 'SS'. It is a jungle of materials and specs. Use 'cheap' hardware store SS, and your carbs will be gone in short time. Use the 'originals' and they will normally hold on. The SS screws used by factory are normally 'neutralized' when it concerns galvanic corrosion and alu. Replace one of the original in your water pump with a hardware screw, and you may see the difference rather shortly.