Topic: More Carb Issues......

[ChopSticks]

Original Issues:

• Pilots clogged
• Petcock leaking in off position
• Different size mains

The petcock is new and has less than 5 miles on it (it's been sitting for a few months tho), not sure why it's leaking. Took it apart and noticed there was rust bits in the filter so I bought a couple of inline fuel filters until I can remove the rust from the tank.

The new Keihin pilot and mains just came in and as I was getting ready to change the pilots I noticed they were clogged again so thinking it would be such a bright idea I decided to disassemble the carbs completely.

As a couple of them are currently taking a Gunk bath, I noticed the additional following issues

New Issues:

• A lot of flaky crud in a couple of the carbs (which is why I'm dunking them now)
• Float need bolt thing is tapered on the ends of 2 of the carbs but not the other two? (see pic)
• I can't for the life of me remove the bolts that hold of the needle to see what position they're in without feeling like I'm going to strip them
• One of the needle claw holder things doesn't appear to be bent like the other 3
• 3 of the carbs are 657A and 1 of them (#2) is 657B, how important is it to have all carbs match?
• What's the point of this hose that is connected in the middle of both sets of carbs? the metal bit that it's connected to is solid and so is the carb so it's not like there is air flowing? (see pic)
• Lastly, any idea what this spring goes to? I've taken apart every piece of the carbs (except for needle) and there was only one of these left on the table  (see pic)

Also, is there an easier way to clean these? Even with dunking them in Gunk and using the aerosol can it still impossible to get all the crud out of the small crevasses. Would a sonic cleaner work? or was thinking of baking soda blasting?

[ChopSticks]

was having issues attaching all pics see below

[evinrude7]

i think you are okay with the one carb body being a B.  i have 3 657a bodies and a 7a body.  i have the original 4th 657a body but when it went out for repair i swapped in a 7a. 

do all your idle air screws have their springs? 

[ChopSticks]

None of my idle screws have springs, and the spring looked a little too big for the idle screw but I'll double check

[evinrude7]

this may help

[ekpent]

None of my idle screws have springs, and the spring looked a little too big for the idle screw but I'll double check

Its not really an 'idle screw' but an air screw and all 4 should have that little spring.

[ChopSticks]

this may help

Thx think those carbs have a bit more pieces than mines or I'm just missing a lot of pieces

[ChopSticks]

None of my idle screws have springs, and the spring looked a little too big for the idle screw but I'll double check

Its not really an 'idle screw' but an air screw and all 4 should have that little spring.

Yeah I think it's to keep pressure on the screw so it doesn't move? I tried inquiring where I could source them but apparently they aren't sold separately anymore

Also any idea if the little hole on the bottom of the IMS supposed to be see through or solid?

[evinrude7]

None of my idle screws have springs, and the spring looked a little too big for the idle screw but I'll double check

Its not really an 'idle screw' but an air screw and all 4 should have that little spring.

Yeah I think it's to keep pressure on the screw so it doesn't move? I tried inquiring where I could source them but apparently they aren't sold separately anymore

Also any idea if the little hole on the bottom of the IMS supposed to be see through or solid?

pretty sure you want those holes clear.  you could probably hit up a hardware store and find some springs or cannibalize from some pens if they'll fit. 

[ChopSticks]

None of my idle screws have springs, and the spring looked a little too big for the idle screw but I'll double check

Its not really an 'idle screw' but an air screw and all 4 should have that little spring.

Yeah I think it's to keep pressure on the screw so it doesn't move? I tried inquiring where I could source them but apparently they aren't sold separately anymore

Also any idea if the little hole on the bottom of the IMS supposed to be see through or solid?

pretty sure you want those holes clear.  you could probably hit up a hardware store and find some springs or cannibalize from some pens if they'll fit.

That's actually a pretty good idea, another spring fell out randomly so I have 2 out of 4 (one is silver the other is brass) I'll start looking at local hardware stores


Any idea what I can do with the needle heights?

[flybox1]

Leave the needles where they are.  If the heads screws securing them are not twisted and ruined, assume they are in stock position.

[ChopSticks]

Will do, I was originally thinking they could be lifted via the bolt at the top but quickly removed that would lift the slides too =/

See any issues with putting them through the ultra sonic cleaner? There's a little crud and rust on a couple of them just trying to prevent future clogging since it's been such a PITA recently

[flybox1]

Cleaning carbs more is rarely a bad idea.

US wont hurt.  The needles and needle jets should also be inspected for wear. 

[BomberMann650]

Clean the rust out of your tank sooner rather than later!  Treat the cause not the symptom.  A few bucks worth of the works toilet cleaner will fill the tank.  Its effortless work and the reward is no more carb clogging!

Really need JIS (or modified phillips) screwdrivers to turn the tiny screws in the slide.
A firm grip and downward pressure worked for me. 

Mis matched bodies are fine.  As long as the jetting is the same.

[ChopSticks]

Flybox - what are obvious signs of wear?

and I'm switching out the main jets so they should be brand new.

Any ideas for the one that is bent? The part that is bent is inside the slides right above the two screws kind of looks like a mini crab claw, it's bent upwards, the other three are parallel to the top of the slide (or perpendicular to the needle) this one is bent a little more than 45 degrees up


Bomberman - toilet cleaner? This is the first I've heard of this. Any specific brand / type? I've done apple vinegar in other tanks, but it looks like the PO previously lined this one. Was thinking of just going over it again with POR15? 

[flybox1]

Flybox - what are obvious signs of wear?
Out of round needle jet center, vertical scrape/wear marks on needle

and I'm switching out the main jets so they should be brand new.   
Upsizing?  Keihin, or some undesirable aftermarket brand?

Any ideas for the one that is bent? The part that is bent is inside the slides right above the two screws kind of looks like a mini crab claw, it's bent upwards, the other three are parallel to the top of the slide (or perpendicular to the needle) this one is bent a little more than 45 degrees up Good picture?  It shouldnt be bent.  Carefully return it to the shape matching the others


Bomberman - toilet cleaner? This is the first I've heard of this. Any specific brand / type? I've done apple vinegar in other tanks, but it looks like the PO previously lined this one. Was thinking of just going over it again with POR15?
The old liner needs to be out before any re-lining, or you're just asking to revisit the whole process in a week or two.
The WORKS toilet bowl cleaner

[ChopSticks]

Flybox - what are obvious signs of wear?
Out of round needle jet center, vertical scrape/wear marks on needle

I look for scrapes on the needle, I do recall the needles being slightly different colors but the actual point were all pretty pokey

and I'm switching out the main jets so they should be brand new.   
Upsizing?  Keihin, or some undesirable aftermarket brand?

Keihin, I got 105, 110, 115, 120, 125, 130, 135 from z1. Figured I'd eventually need them. The PO set up had mismatch. Since I have a K&N figured I'd start with 115 and go from there

Any ideas for the one that is bent? The part that is bent is inside the slides right above the two screws kind of looks like a mini crab claw, it's bent upwards, the other three are parallel to the top of the slide (or perpendicular to the needle) this one is bent a little more than 45 degrees up Good picture?  It shouldnt be bent.  Carefully return it to the shape matching the others

Try to get another pic once I have them in front of me again

Bomberman - toilet cleaner? This is the first I've heard of this. Any specific brand / type? I've done apple vinegar in other tanks, but it looks like the PO previously lined this one. Was thinking of just going over it again with POR15?
The old liner needs to be out before any re-lining, or you're just asking to revisit the whole process in a week or two.
The WORKS toilet bowl cleaner

How can you remove the old lining?

https://www.dollartree.com/assets/product_images_2016/styles/xlarge/170085.jpg

This one? do I just need enough to swoosh around or enough to fill the tank to the top?

[PlungerWaffle]

Get a guitar string or paper clip to clean out those impossibly small holes.

[flybox1]

I personally prefer acetone

[ChopSticks]

PlungerWaffle - I was thinking of just soda blasting then dropping it in the ultrasonic cleaner

Flybox - whoa, hopefully it's as easy as it looks. okay so 1 quart of acetone, rotate every 30-60 minutes? then WORKS toilet bowl cleaner, rotate again? do I need to reseal? or if I top it off with gas it should be good?

[flybox1]

You'll have to assess after the removal of the liner and works treatment. 
I would only use a liner if my tank had pinholes.  Seems their success is highly dependent on tank prep.

[ChopSticks]

Alright so I just reassembled the carbs after ultrasonic bath with Simple Green HD Pro. Must say they came out better than expected.

One issue I noticed which may be the cause of the dropped choke slide, is if I tighten up the bolts holding the choke and then turn the choke on and off a few times the bolts become loose again. If I do it enough 10+ times they get really loose... is this how they should be? or should they always be tight?

The choke bolt has a crush washer, regular washer, and plastic washer.