Need New Needle valves - Source?

[WilliamGLX81]

Hey everybody. I'm getting my gs650gl back on the road.

I pulled the carbs because they were overflowing in prime (Petcock is new and working great). Found 2 of the 4 needle-valve needles have very weak springs with dead space - makes me think they broke or corroded internally.
Anyway, the needles show 0 wear. Is it necessary to replace the needle and seat in a set? I expect the other 2 needles may fail not far behind these others. I plan to replace 4 of the needles, and seats if that's best practice.

I've seen posts that J&L needles have weak springs and it is difficult to measure float height. That doesn't seem to me like it would be very reliable either to put in a weaker spring, but eh.

1) Do I need to replace the seats along with the needles despite 0 wear on the needles?
2) Is there a good source for genuine ones, or would I be fine with the cheap ones?

Cheers

Update: I found two places selling them using a cross-reference number. The two appear different, one with a brass pin in the needle, the other with the same material for both needle and pin.
https://www.oldbikebarn.com/parts-b...s550l-mz-t-81-82-gs650-float-needle-seat.html
and
http://www.partsnmore.com/parts/suzuki/gs650gl/?filters[category]=carb&filters[fitting]=custom for just the needle. There is a kit available for $14 per with needle/seat/o-ring, another o-ring, and the gasket.

 

[Nessism]

You can find real deal Mikuni float needle/seats for reasonable prices at Amazon. You just need to find the part number you need and then go search. https://www.jetsrus.com/needle_valv...eedle_valve_and_float_bowl_gasket_mikuni.html

FYI: the part numbers have a suffix on the end with references the hole size which references flow.

For example: https://www.amazon.com/gp/product/B000TG1EE6/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1
Not sure if these are the same as for your bike but you get the idea...

 

[rapidray]

Just so you know, MOST times the leaks are from the oring around the needle seat BODY. The needles and seats rarely go bad. Change all 4 of those seat orings and see what happens first.
Ray.

 

[WilliamGLX81]

Just so you know, MOST times the leaks are from the oring around the needle seat BODY. The needles and seats rarely go bad. Change all 4 of those seat orings and see what happens first.
Ray.

Hmmm. I know I put in one of the O-ring kits from the board. I would have replaced them if they were present, and I think I did. It really does look like the two that were leaking (and had corrosion) have the failed springs.

 

[tom203]

" I would have replaced them if they were present, and I think I did."

Hmm...maybe you got distracted.. I'd try some new needle seat o-rings. Ordinary hardware store buna ones will work - they swell up nicely when they see gas! Look for correct i.d. to fit seat groove snugly.

 

[WilliamGLX81]

Looking closely at the valve seats, there is some corrosion around them between the brass and aluminum/magnesium carb body. I am pretty sure they aren't the issue, but I might as well get the kit that has the seals and seats so I don't have to worry about mangling them to get them out.

Are there any good tricks to remove the things? Hit it with a heat gun?

 

[WilliamGLX81]

I got the old needle valve seats out. The o-rings had bonded permanently to both surfaces, and no penetrating oil made a difference, even after they were broken free. I'll need to clean the remnants of the o-rings out. The o-rings disintegrated in the seat bores. Weird, but not too bad. I got pretty medieval on them (for a soft-metal cast carb), but got them out. I could post photos, but the procedure is a bit risky. Suffice to say, it involved a 3/8" drive T35 torx bit, a hammer, a ratchet, and a small pair of channel locks. The trick was to keep the torx bit in the seats and grip the seats so that the brass is sandwiched between the pliers and the torx bit. This way it doesn't deform. Again, not recommended to the new or amateur mechanic.


I thought I ordered genuine Mikuni, but I made a mistake and wound up with Keyster brand instead. I've never heard of them, and the needles' internal spring-loaded shafts seem to bind a bit when first moving through their bores. It feels like a lip is catching because there is play and maybe rough edges inside the bores.

I found some Mikuni for ~15 each with shipping at https://www.denniskirk.com/mikuni/s...-for-rs34-40mm-carbs-n149-040-2-0.p170352.prd Is it likely worth returning the others and getting genuine Mikuni? Is there really that much difference?

 

[Nessism]

From what you describe about removing that needle it seems you never properly disassembled the carbs and cleaned them. That's what i'd do first. Tutorial on Basscliff's website and linked in my signature. Regarding the float needles and seats, yes on getting new OEM parts.