HELP! XJ550 idle mixture stripped

Hi, first post for me here. I've been lurking on the forms quite a bit as I work on an 82 Seca 550 I picked up a couple years ago. I'm in the process of rebuilding the carbs and everything was going good till I got to the idle mixture adjustment screws. I drilled and pulled the factory caps as described which led me to believe the the screws had never been messed with. I took out screws 1-3 with no problem but when I got to #4 it would barely turn. I worked it in and out but it just became more stuck. I finally used an easy-out to get it out destroying the screw.

When I got it out, the threads were all mashed on both the screw and the housing. My question is, can I reap the carb housing and find a new mixture screw? The threads seem very fine and I don't have a tap that fine. I also don't know where to find a new mixture screw. I searched eBay but didn't see anything.

Thanks, Dave

 

I got a new mixture screw from a guy breaking(parting out) some carbs on ebay so it's possible. I think I saw he was selling the float bowl and I asked if he had the screw - which he did..

The next question is can you tap a new thread ? Well you could try cleaning it up if you can find such a diddly tap (M4 0.75?) but frankly I'd be looking for a replacement carb in your shoes I think - less long term hassle.

Cheerss

 

Thanks, I was thinking about a new carb body as a possibility as well. I found someone who has a couple for sale but he lists them by position number. Are they interchangeable? In other words, my #4 carb is the one with the stripped pilot valve. Do I have to find another #4 position carb?

 

Yes. 2 and 3 can swap, but 1 and 4 are unique to those positions.

 

You can click on the banner in the upper right hand corner or contact member Chacal to order new mixture screws. He also sells the associated o-rings, washers and springs if those need to be replaced as well. The correct tap for chasing the mixture screw threads is also available from him as well as a nifty little adjusting tool that makes mixture screw adjustments a snap while carbs are on the bike.

He may also may have a used carb body if that is the route you need to take and he ships super fast!

 

here's one..

http://www.ebay.co.uk/itm/Yamaha-XJ...eedle-Choke-/351473816411?hash=item51d578d35b

A bit dear though. I'd start by offering half that and see where it goes..

 

100man, I saw that one, I thought it was a little pricey too. I can't tell entirely, but it doesn't seem to include the mixture screw either. I would still have to buy one of those. I think I'm going to try and track down a tap to chase the threads in the one I have and them put a new mixture screw in. Thanks for the help!

 

You're right - looks like teh miserable b*gger has stripped out all the jets/needles. I would try Chacal as suggested (XJ4Ever link on top RHS of this page) - he has an excellent reputation for parts supply.

 

Just an update here. I ordered two new mixture screws, a tap, and new o-rings from Chacal (xj4ever). I am thoroughly impressed with the knowledge, information and service I received. Parts showed up a few days after I ordered them.

I ran the tap through all 4 pilot mixture screw ports to clean them up, replaced the o-rings and installed the mixture screws. They went in like butter.

Thanks for all the help..

-Davr