Keihin MK1 & MK2 side by side

Thanks for posting the photos. I was just going to hop on the UHE to research the physical differences between the MK1 and MK2, and here they are. I'm about 99% of the way to fitting an FCR to my '03 FE400. I'm assuming that an MK2 will fit, that's all I've come across thus far.

On a side note, is there that much difference in the performance of a 41mm as opposed to a 39mm; especially given the $$$ difference. Lastly, are there any fit issues? I'd thought the bowl drain nipple may need to be ground off, due to clearance issues with the starter, is that true?

Thanks....

kzoo
After mounting a 41mm MK2 on my 470, if I was going to do it again I would look at the 39mm MK1.
The MK1 clears the starter better because of the angle of the body, you can buy an intake boot that fits the carb and the filter boot clamps right on.
To fit the MK2, I had to cut off about 1/2" from the intake boot, machine it out to fit the 41mm, grind off the nipple on the bottom, dimple the pipe to clear the fuel inlet and make an extension so I could clamp on the filter boot.
The one nice thing about MK2 though is the remote hot start.

buckwheat5679 said:

To fit the MK2, I had to cut off about 1/2" from the intake boot, machine it out to fit the 41mm, grind off the nipple on the bottom, dimple the pipe to clear the fuel inlet and make an extension so I could clamp on the filter boot.
The one nice thing about MK2 though is the remote hot start.

Click to expand...

fitted a mk2 39mm to my '03 400 and would agree with the above

Concerning the float bowls, and fitting one up to a Berg, I found that KTM-Husaberg use a different bowl than the Japanese companies. The KTM bowl has the drain nipple going out horizontally, with no screw drain valve. Also, the KTM bowl has no machining to use a leak jet. I actually purchased a Honda part number float bowl to play with, experimenting with leak jets and such, on my 2006 FE450. I actually fitted a 90 degree L for a drain nipple to clear my starter. On 550 and 650 applications you have more room to play with. The AP diaphragms are indeed different, giving you tuning options as to the entire volume of AP squirt. I am now using one from the 2006 Honda CRF450R.

I don't know how many different float bowls there are out there for the FCR carb, but one company makes a bowl with a screw jet adjustable leak valve. I would really like to play with one of those, just too much money.

Hope this helps more than it confuses.

your mark 2 wasn't off a 2-stroke was it???????????????

regards

Taffy

Re: RE: Keihin MK1 & MK2 side by side

kzoo said:

Lastly, are there any fit issues? I'd thought the bowl drain nipple may need to be ground off, due to clearance issues with the starter, is that true?

Thanks....

Click to expand...

Yep need to remove the bowl drain nipple.
39mm FCR MK2 FE400

RE: Re: RE: Keihin MK1 & MK2 side by side

Thanks for the advice everyone. Found an MK1 locally that I'll be buying this weekend.