Howto: Replace your stuck carb drain screws

On the bike I sold to Doc, every screw was hopelessly mangled. I heated each bowl with a heat gun until they smoked, about a minute, maybe a bit more. A very sharp slotted screwdriver dug in enough to grab what was left and they came out relatively easily.

Not knowing where to look, I hopped on bikebandit.com. $25 each. Eff that.

I went down to the hardware store, bought four allen-head, grade 10.9 metric bolts. Chucked each bolt in my lathe, cut back the threads and recreated the taper on the end of each. Cut the head off of each bolt, and slotted them with a dremel. Made them about 3/4" longer than stock, so you could mangle them up as much as you'd like, and could trim it off and re-slot them.

Kind of moot at this point.

 

Most folks probably would have left the Allen Heads on.
Specially on stainless.

 

They weren't stainless, they were alloy steel. I've had too many cases of stainless galling to give them serious consideration. I don't normally consider the use of stainless fasteners when I put stuff together. Plus, stainless gives me trouble on my lathe.
I don't think the inner ones would be easily accessible by hex key; I wanted them to be reliable and easy for whoever bought it. A screwdriver is all that's needed, something you could keep on the bike or easily borrow in an emergency.

Also, the total sum was under $5.00, and about 1/2 an hour of work (aside from driving to the store).

 

Awesome post... Am I the only one that can't see the pictures? I'm just getting little question marks where the pictures should be.

 

no, the pics were lost when the forum was changed. it's an unfortunate loss, because there are so many posts that require the pics. there are a lot of broken links as a result of the shift as well.

FU

 

What a shame... I guess Gremlin484 is no longer active on the forum, to get those pics re uploaded... I clicked on his screen name and it said, last seen March 28th 2010.

 

yeah, that is just the way forums go.

FU

 

I agree! This is an excellent post. So great, I copy and pasted it onto my computer to keep. Thanks dude. You rock!




Motocross Pants Womens

 

Hi all. I know this is an old thread - sorry if reviving it is bad form. I'm wanting to replace my carb drain screws, but I have VERY little experience and what might be obvious to most here is mystical to me.
My drain screws aren't stuck, but the heads are very nearly stripped so I thought I should proactively replace them now.
1. Can I replace them without removing the carbs? Just, unscrew them and screw in the new ones (with gaskets)?
2. What should I have the fuel valve set to when I do it? PRI, ON, or RES?

 

You won't have good access to them on the bike, but it can be done. The petcock should be set to ON so gas won't flow from the tank (vacuum operated petcock). Have a length of fuel line and a bucket handy to catch the fuel from the float bowls in. The drain screws do not have gaskets or o-rings on them. They seal against a taper in the float bowl.

Please start a thread for your bike that includes the year and model and type of XJ.
Before starting any work Read This First
Welcome to the best motorcycle forum on the planet

 

MIKUNI float bowl drain screws do have o-rings on them.

We need to know what bike so we can provide bike-specific accurate answers.

 

Thanks guys. Good advice, I'll start a new thread with the deets.

 

https://www.xjbikes.com/forums/threads/replace-carb-drain-screws.129288/#post-649901

xj550

 

This should read "Most Mikuni float bowl... or "Some Mikuni..." I have just been informed that later (post '83-ish) Mikunis shifted away from o-rings on the drain screws. So while the Mikunis fitted to the XJ550s will have o-rings, those on later models may well not have.

Making it even more important that we know what bike we're talking about.

 

+1

A friendly reminder to the collective (particularly the new members: put the bike info in your signature. If you have multiples, make sure to mention which one you want help with in the post or thread title.