Carb replacement with Mikuni or Keihin?

[qwertylolman]

Hi guys, I'm thinking how I can improve carburetors. I'm not happy with jet price and parts availability for our Teikei carbs. Although XTZ660 getting older with evey year and it's became uneasy to find some parts. Is it possible to replace our Y.D.I.S. carbs with two regular CV carbs?

[xtzrick]

Some models of the 660 Raptor quad used BSR 33mm mikunis as standard.
You will probably need raptor mounting rubbers to fit them.

BMW f650s like the funduro & early 650GS & Suzuki DR800s also use them & are easier to find 2nd hand
Not sure about spacing & the jetting will be different.

Rick

[qwertylolman]

Raptor has the same diameter for intake for both er... i don't know how it called. place where manifolds mounts to cylinder. so i'm not sure. i've found thread about mounting 35mm keihin cr to xt600, but xt600 has the same diameter for both intakes. and i'm sure that pair 31 and 39mm carbs woun't be a good idea xD

I'm thinking about ducati monster carbs.

[neale]

Don't know about a pair of Mikunis or Kheins, but you can get the Grizzly 660 2 into 1 manifolds, the 2 slightly shorter ones (without the boot) in this pic are the 660 ones, the other one is the 600 one I was trying to get at first.



Anyway, you can use this with a bigger Mikuni HSR or Khein carb, the Mikuni HSRs are designed for performance Harley motors, so they'll flow enough for a 660, easy.

FWIW

Neale

[qwertylolman]

Don't know about a pair of Mikunis or Kheins, but you can get the Grizzly 660 2 into 1 manifolds, the 2 slightly shorter ones (without the boot) in this pic are the 660 ones, the other one is the 600 one I was trying to get at first.



Anyway, you can use this with a bigger Mikuni HSR or Khein carb, the Mikuni HSRs are designed for performance Harley motors, so they'll flow enough for a 660, easy.

FWIW

Neale

nice... many thanks! i think this thing and FCR 41 will be awesome :)

[qwertylolman]

nope, 2in1 didn't fit :(

[qwertylolman]

hi again,

what do you think about this? it's MZ Skorpion with some Mikuni. i'm not sure about length of intake manifolds. can they be so long? i heared that the shorter - the better.

[Mezo]

Well im guessing that is why the factory Dakar race bikes went with a downdraught carbie, the gas tank was made with a hole to change the filter, your problem is space & you have no choice but to have long inlet.

Mezo.

[xtzrick]

Wouldn't have thought a few centimeters longer to the carb would make much difference on a 4stroke single, gas speed is a few hundred feet/second. Cars with carbs have really long manifolds compared to that MZ but can still be resonably responsive.

Sharp turns in the manifold might be more of a problem if you are looking for more power.

I thought the reason they use down draught carbs was to straighten the inlet track, fewer turns

Rick

[xtzrick]

This is the set up I want if my bike ever runs again


Mikuni VM26 or 28 for the left carb with a BST40 flat slide for the right, linked the same as the teikei original so the VM starts to open before the BST.
Both carbs fit in the original mounting rubbers



This BST is from a Cagiva 600 I'm mending so don't want to pull the petrol tail out, there looks to be enough space for them to sit next to each other if I feed the petrol lines to the outside, there's even a chance the fuel rails will line up which would be nice

Rick