Topic: Damaged main jet housing in carb, should I keep it?

[drrice]

I found a slight crack in the housing of the main jet in my carb. Does this damage look bad/typical. Should I put JB weld on the area to prevent the crack from growing? Or is JB weld not a good match for the gasoline in the carb?

Thanks

[Greggo]

Doesn't look good.  Two towers just like that forced me to find new carbs for my 750.  Then again, if no gas is getting past the jet threads, it may be okay...

[drrice]

Damn, that's bad news. Were you running lean with your towers like this? The cracks don't seem deep. I am hoping JB weld can address this before it becomes a problem.

[Greggo]

Damn, that's bad news. Were you running lean with your towers like this? The cracks don't seem deep. I am hoping JB weld can address this before it becomes a problem.

No, if there's gas getting sucked up past the threads, it'll run rich.  Hopefully someone with more experience using carbs like that will come along with advice.  My bike came to me not running, and I decided not to waste time/money on that set of carbs.  I got it to fire up with that set, but that's as far as I went.  I think mine looked worse.

[Magpie]

There was a post here somewhere where a housing was fixed by cutting the end off a 45 calibre cartridge and slipping it over the housing. No bull! So maybe some JB Weld on the post and the shell casing for added strength. Cliff.

[ekpent]

Hey Cliff I was the one who did the recent 'Ghetto' fix.
  The crack is a bad thing,somebody tightened the emulsifier tube too tight and it could break off or get worse with another install and also won't perform correctly.
  Look for a .45 ACP handgun cartridge and trim it down to fit the post to make a sleeve. Clean well and scuff the inside of it and the carb post with sandpaper. Get a product called Seal-all http://www.totalmotorcycle.com/reviews/SealAllGlueReview.htm  and fill the crack and also whatever void between the case and post to make a tight good seal.Coat the post and inside of case. Make sure you carefully install the main jet emulsifier tube first in case the crack should widen.Let it dry well and you should be good to go. 
   If you can't find a cartridge case give me a shout.     Eric

[78whiteorbs]

I did this as well , it was originally posted here- http://therng.yuku.com/topic/373?f=1#.TvsxtlZ_hTI
I used an aluminum shell casing which matched and looked almost like it belonged there . One word of wisdom make sure you tap the casing down flush with the tower and I had to dremel a little material out of my carb bowls, actually nicked one overflow exit and had to patch.

Ekpent, I did some reading and that Seal All you refer to  is advertised as fuel resistant not fuel proof. I used JB "Stick" which is advertised to be fuel proof and will even cure submerged in gas. It sets quick and is good stuff, not all runny like traditional JB. More like clay . I also have spare shells if any one needs them- aluminum ones too!

[ekpent]

Hey Whitey I have not ran mine yet,think it should be fine.Has your repair been on the road yet ??   Eric

[78whiteorbs]

Yes Sir, worked the charm. The shell casings are actually tapered to it seals nicely . Notice improvement right away. Synced my carbs and I can actually cruise around slowly with out the hurky jerky uneven acceleration!  One big thing to watch out for is the clearance issue with the vent tube in the carb bowl. You can remove just a little bit of aluminum and it slide on perfect but be carefull because if you go just a tad to deep you have a bowl that will constanctly be draining. 

-Brian

[drrice]

Thanks for the info guys. JB Stick is exactly the material I am looking for then. I'll go to my local range and ask if I can pick up some spent brass. I'm sure they won't mind.

Brian, I'd like to use aluminum but I think that brass might be a bit more fitting to put in there since it is a bit softer. I think it'd conform more to the housing as you tapped it in.

[drrice]

I decided to use the brass .45 casing and JB Stik. I think the JB Stik was a bit too hard to work with. I am going to try JB waterweld instead for the next 3 carbs. I am going to put shell casings on all the towers to prevent this from happening again.

Here is how I cut the shells. I'll add this to the tricks/tips.










There was carbon build up inside the casing.


After some 80 grit sand paper


600 grit


Thanks for the help guys.

[faux fiddy]

Dang, these guys are great. Looks like a fix to me.

Oh, and to answer the question in the title, don't trash anything unless you absolutely can't store it or if it has had a true catastrophic  existence failure and you don't want it for a conversation piece.


 Lemme see if I can find another direction for this problem, right here on the forum search feature.  Sure enough, several posts under searching "Laser Welding."



http://forums.sohc4.net/index.php?topic=18649.0

[ekpent]

If it was me I think I would just fix the one carb that has the problem and leave the other 3 as stock as possible if they are in good shape. The old saying'If it ain't broke,don't fix it" usually rings true.I have not encountered this problem very often,only twice, on many sets of carbs I have worked on over the years. Make sure you take a round file and chamfer the area you cut to smooth out the inside good before you mount and seal it with whatever you choose..
   The micro welding is also a good option,there is a fella here that does do that.