Hi All,

 My son and I are going through our CT3, getting various things sorted properly.

A previous owner had replaced the original carb with a chinese knock off.  It runs... OK, I guess, but I am a bit particular about jetting, and I know this carb will not be tunable beyond the air screw, and maybe the needle clip ( haven't looked yet - maybe not even that! ).

I think it might be best to get a used VM24SH from a CT2/3, with all the correct bits that Yamaha chose back then.  Unfortunately, they are not common on eBay, and those that do show up are in poor shape.

The new VM24s are spigot mount, so it seems a flange adapter would have to be added.  I would prefer to keep the original airbox, and this may make the fit problematic.

The VM24SS from a DT175A and the VM28SC from the MX175 seem like they might work too.

What have you found that works?  Would a VM26 work better?  Is there a Keihin that works for this?

Does anyone have an original VM24SH they might part with for a fair price?

Thanks!
-Ted

Well, I am at a similar scenario… I have a spigot mount that MIGHT work on my RT2… I think it would be alot easier to do jets… Loosen it up, give a twist to get to its..”undercarriage” and do what’s needed..
Sneezles61

These no name carbs are rarely compatible with genuine Mikuni parts. Parts are not available. They are not even rebuildable, as kits are not offered for sale ( the manuafacturers are nameless ). They intend for them to be thrown in the trash and replaced.

I will do so - with a genuine Mikuni or Keihin...

I'm not sure if I have a CT3 carb.  I know I have a couple AT carbs.  It will be about a week until I can take a look.  And I'll probably forget. 

 

Ha well, i'm going to put a TM 26 on mine . Mine isn't a standard bike in this case . It's fitted with a GYTR pipe and i'm not running the oil pump in this one.
I converted a GasGas TXT 250 from a PBH 26 to a Kehin flatslide.
It makes it smoother and very sensitive to input control.
When you open the throttle ,it's open and you know it.
If you put a VM26 on ,you will have to open the carb to reed valve block aperture by 2mm or the conversion will be useless .

Thanks Mark - I'll ping this post at the end of the week to hopefully remind you.

An AT2/3 carb is pretty close - I would just want to change out the slide.  I haven't looked - I hope they are still avaialble.  The jets and needle would be replaced with new when rebuilt.

Shyted - Good info on the TMs - I was looking at those on the Mikuni USA site yesterday.

The Mikuni sizing chart shows a 24mm is the right size for a 15HP jug, so I will probably stay with that size.

No luck with eBay carbs yet.  Pretty ugly stuff - After getting it ready, I'll end up at the same price as buying a new genuine Mikuni.

So - anyone out there with a decent CT2/3 carb that's willing to sell for a fair price?  Mark - Any luck looking in your parts stockpile?

Interestingly, the Mikuni flat slide carbs look good.  The VM28 ( flat slide despite the part number ) actually is closer in dimensions to the round slide VM24-512 than the TM24 is.  Just need a flange adapter to use the modern carbs.  The DT175A seemed to use a flange somehow.  Hmmmmmm.....

 

Summit racing sells a Mikuni flange adapter for the VM28-200k if you decide to go that route. I personally have not tried it but wanted to go that route while shopping for a carb yrs ago. Luckily I found a NIB origional carb on ebay.

The 1975 DT175 uses a flange mount. It seems like you could take the DT intake parts and put them on the CT. Reed cage has a different part number.

The gasket is the same!

DT :345-13610-20-00
CT: 53V-13610-00-00

Does anyone know if the DT carb joint will fit right on the CT reed valve ?

I guess if you found the set at a reasonable price, it might just bolt on.

Tee Cee wrote: The 1975 DT175 uses a flange mount. It seems like you could take the DT intake parts and put them on the CT. Reed cage has a different part number.

The gasket is the same!

DT :345-13610-20-00
CT: 53V-13610-00-00

Does anyone know if the DT carb joint will fit right on the CT reed valve ?

I guess if you found the set at a reasonable price, it might just bolt on.

Caution...  13610 in the part number is the reed valve .  it just means "reed valve"...  having 13610 in the part numbers does NOT mean those parts are the same.  Part number prefix is critical. 

87A-13621-00-00 is the part number for the gasket...  the 13621 number will be found in almost any Yamaha reed valve gasket...  it just means "reed valve gasket".  The 87A prefix and part suffixes (-00-00) also being the same on the gasket part number 87A-13621-00-00 for both models means the gasket is the same.  You simply can't look at a section of the part number.  You have to compare the whole number.