Yam_Tech314's official build thread

[gggGary]

Is the jet that sits in the choke hole removable?

No it's fixed in place.
The hole is very small.
The usual test is to shoot carb cleaner through it from the top so it sprays out the angled hole. WATCH YOUR EYES!
The idea is you want to push any blockage BACK out the angled bottom hole.
I keep a couple pieces of safety wire sharpened to a fine point at the work bench.
far left here

I start by probing into the orifice with the wire from the top.
That's usually enough to free any blockage, but the hand drawn pic shows the "ultimate" blockage clearing technique, using a hooked piece of safety wire to root out a plug of varnish/rust debris. Repeat probing from the top, alternate til the passage is open, lets spray cleaner through.

 

[gggGary]

see edits to post above.

 

[G_YamTech_314]

I've got a few strands of heavier gauge wire that I'll try and separate and use a single strand to probe the orifices and get everything cleaned out. There's gotta be a blockage in the circuit somewhere. I'm suspect of the long brass tube that rides in that passage having a clog.

 

[gggGary]

I've got a few strands of heavier gauge wire that I'll try and separate and use a single strand to probe the orifices and get everything cleaned out. There's gotta be a blockage in the circuit somewhere. I'm suspect of the long brass tube that rides in that passage having a clog.

Red is fuel, blue-air, pink the mix.

 

[gggGary]

View attachment 349033

check throttle shafts for any sideways play especially the side the throttle cable hooks to. As long as you are here (if you haven't) do the throttle shaft seals

 

[G_YamTech_314]

check throttle shafts for any sideways play especially the side the throttle cable hooks to. As long as you are here (if you haven't) do the throttle shaft seals

If I recall correctly, aren't the shaft seals compatible to a Suzuki p/n? I'll be doing all of my parts ordering tonight and replacing them just to be safe

 

[gggGary]

If I recall correctly, aren't the shaft seals compatible to a Suzuki p/n? I'll be doing all of my parts ordering tonight and replacing them just to be safe

https://www.xs650.com/threads/the-g...es-used-on-the-xs650-thread.51957/post-728065

 

[Jim]

https://www.xs650.com/threads/the-g...es-used-on-the-xs650-thread.51957/post-728065

That writeup is for the 34's. Do the 38's use the same seal?

 

[gggGary]

That writeup is for the 34's. Do the 38's use the same seal?

yes

 

[Jim]

yes

Show Greg a pic of your handy dandy homemade tool for backing up the shaft while you remove the butterfly screws?

 

[gggGary]

Show Greg a pic of your handy dandy homemade tool for backing up the shaft while you remove the butterfly screws?

As you command sire:




The throttle shafts are chrome plated brass it's pretty easy to bend them. this support stick lets you bear down so you don't strip the head, and loosen the screws with only two hands.
Make the stick long enough so you can clamp it in a vice,
This one was pine but the mk2 version is made of oak. Just a piece of 3/4x 1 1/2" fitted to the carb throat.
After the screws are out The butterflies can fight coming out of the shaft slot, tape the jaws of a small linemans or duck bill pliers keep the butterfly straight (watch the screw holes) a bit of rust buster helps, DO NOT force, if it sticks, push it back try again. Be careful with the butterflies, the sharp angled edges are critical to proper idle, do not mar or round those edges!

 

[5twins]

You'll need J.I.S. screwdrivers for the butterfly plate screws, I wouldn't even attempt removing them without them. Also, you'll need to grind the factory peened end off the screws .....

I used to use the ball cutter pictured above and while it works, I've found that the diamond dust coated ball cutter works better, so that's what I use now.

https://www.amazon.com/dp/B0DS8TR3F...industrial&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWw

And for replacement screws, you need M3 x 8mm long .....

 

[G_YamTech_314]

I somehow didn't get notifications that any of you guys said any of this. I will be ordering a JIS screwdriver kit this afternoon (or grinding one down like @Jim has done in the past...) I'm a bit ill-equipped at my house to be getting the butterflies out. I'll need a Dremel and some tips for the peened ends.

As far as the butterfly holder goes, that's pretty cool. My vice is at my dad's house (I'm here now but my carbs are two hours away )

They're gonna stay apart longer than I wished but if it's gonna get done... It's gonna get done right.

 

[G_YamTech_314]

Do I need 4 of those butterfly shaft seals? I'd imagine there's one on each side of each carb?

 

[jetmechmarty]

Do I need 4 of those butterfly shaft seals? I'd imagine there's one on each side of each carb?

That is correct. Cheaper if you use the Suzuki part number in the o’ring thread.

 

[G_YamTech_314]

That is correct. Cheaper if you use the Suzuki part number in the o’ring thread.

Yep. I got it! Screenshots in that thread show a little over $1 for em. They're $2 something on OEM sales sites. Inflation sux!

 

[Jim]

I somehow didn't get notifications that any of you guys said any of this.

The notification thingy has been a little wonky lately for me as well.

 

[jetmechmarty]

Re, notifications.

I use a yahoo mail account for this site. I seldom open it. Early this week I was kicked off of this site until I went over to Yahoo and jumped through the hoops of email verification.

 

[G_YamTech_314]

Re, notifications.

I use a yahoo mail account for this site. I seldom open it. Early this week I was kicked off of this site until I went over to Yahoo and jumped through the hoops of email verification.

I use my standard everyday email, and usually get pretty reliable notifications. I sat patiently all weekend (not really checking the forum) and didn't see any replies for a confirmation of the butterfly shaft seals, so I just kinda let it go. I logged in to read up on Jim's paint thread and saw 4 separate notifications but had no emails for em'. Oh well. Everything is ordered and on its way

Dremel
JIS driver set
Polishing kit for Dremel
100 count screws for butterfly valves
Seals for the shafts

I'm gonna have a load of packages coming to my house this week lol

 

[Wingedwheel]

https://www.amazon.com/VESSEL-BALL-...81827&sprefix=jis+screwdriver,aps,164&sr=8-11
This is the driver I use and it’s very nice. Heavy with a really good magnet.