rebuilt carbs overflowing - @ random?

[DogBunny]

"I did use the old needle but not the old seat. will try that next."

I think this is your problem.
BTW, the Mikuni seat will have a tiny Mikuni symbol, which is a square within a square, stamped on it. Just in case you mix them up.

 

[DougXS2]

I'm still baffled as to why I can fill them up (held in a bench vise) and can't blow air or more fuel into the bowl. then back on the bike, after a long ride I get puddles if I dont shut of the petcock.

will switch the seats and report back. thanks

 

[5twins]

Yes, you never want to mix seats and needles if possible. A matched pair sort of "beds in" or "breaks in" over time. Sometimes you can get away with just a new needle if the old one is badly worn with a groove in it but usually it takes a complete new set (needle and seat).

Also, you have to realize that the needle/seat assembly was never meant to be a complete shut-off valve like a petcock. A full tank of fuel pressing against it can overpower even a good one. You have to train yourself to turn those petcocks off when you park the bike.

 

[vr3506]

I've put needles in 2 of my bikes with Viton tips they work fine for many years already
I think they were originally ment for a H**nda 1200 Goldwing

 

[5twins]

Yes, that's what we need for these 38s, a viton-tipped replacement. Several guys claim to have done it but no one seems to remember exactly which part it was Frankly, that's not much help then, lol.

 

[vr3506]

Maybe this makes you happy

Sorry, they were from a GL1100http://www.mijnalbum.nl/Foto-SKQWFDCG.jpg

And to make it even easier for you

http://www.carbkitscapital.com/carb_kit_list_model.php?make=Honda&model=GL1100

 

[5twins]

Now that's the ticket, thank you. Here's a better cross-referance .....

http://4into1.com/k-l-keihin-float-needle-rubber-viton-tip-honda-cm200t-cb400t-cx500-cb550-cb750/

Very commonly used needle it seems.

https://jetsrus.com/individual_parts/KL_18_8953.html

https://jetsrus.com/individual_parts/018_880_su.html

 

[acebars]

I know it's an old thread, vr3506 I just bought a set of GL1100/GL1200 float needles identical part number to yours.

They do not fit on my '73 TX650 carbs, did you fit just the needle or the seats to them also?

I'm lead to believe XS-1 carbs have different needles and seats to the later models.

 

[vr3506]

Oops it's over 10 years ago
If I remember they are just a little
Longer, so the float needs to be re-adjusted
I didn't use the seats, and yes they do fit in a XS1

 

[acebars]

Oops it's over 10 years ago
If I remember they are just a little
Longer, so the float needs to be re-adjusted
I didn't use the seats, and yes they do fit in a XS1

I'm lead to believe the XS-1/XS-1B has a wider needle seat than the TX650 and XS-2 (mikesxs sells different needles for those different models so there must be a difference).

The GL1200/1100 float needles are too wide for my TX650 carbs and I believe XS-2 carbs also.

 

[vr3506]

http://www.louis.de/_30110931e0f358...ic=search&searchterm=10043000&cmd.x=8&cmd.y=7

These do fit a BS38
I use the GL1100 needle in my XS1

I have some seats here with an inner diameter of about 5,2mm

 

[acebars]

http://www.louis.de/_30110931e0f358...ic=search&searchterm=10043000&cmd.x=8&cmd.y=7

These do fit a BS38
I use the GL1100 needle in my XS1

I have some seats here with an inner diameter of about 5,2mm

I believe the XS-1 carbs have a different needle and seat to the later XS-2 and TX650 models.

It is possible the GL1100 needle fits the XS-1 but it does not fit the XS-2 or TX 650, I have the parts in front of me.

XS-1 seat and needle:

https://www.mikesxs.net/product/48-1429.html

XS-2 / TX 650 seat and needle:

https://www.mikesxs.net/product/48-5019.html

Clearly there is a difference.

 

[5twins]

There is a difference in the metering orifice size, that's all I think. Needle and physical shape and size of the seat are the same. The XS1 and XS1B use a size 2.5 needle seat, the '72 and later BS38s use a size 2.0. These size numbers refer to the size of the hole in the bottom, where the fuel flows through.

 

[XSLeo]

On old seats they often don't come perfectly clean. A tip from XSJohn was to peel the cotton off a q-tip. replace the cotton with 4-0 steel wool. Use a bit of carb cleaner on the steel wool and spin this steel wool q-tip to clean the seat, this removes all the crud and polishes the seat bright and shiny. It removes any burrs in new seats to.
A bit of steel wool and cleaner will clean the float needle tips too.
Leo

 

[jamesgs4]

I gave up on these old carbs and just installed one of these.
http://www.jpcycles.com/product/ZZ7...g&matchtype=&gclid=COvR6c-2870CFc9AMgodYDQA3g