did a 300ex choke ever have a yellow lever?

[maddmatt02]

I know my boss's 300 is black, 400 was yellow...

I ordered a 300ex carb off ebay and I think I got a 400. because it was a pain getting the carb into the manifold and I dont even think it will fit into the air box boot! what do people do when running 400 carb in a 300, I was thinking of boiling the boot and then trying to fit it over, but I didnt wanna have to do it every time.

do 250x's have the same I.D. size as far as manifold and airbox boot, I think I have a boot off a 250x but I thought it was thew same, I think my manifold is a 300 though and it was a squeeze.

[chads300]

my choke lever is yellow... if you are still unsure i can post a pic up of my carb for ya.

[bwamos]

Choke lever is yellow on both my 300ex carb and 400ex carb.

For the 400ex carb on the 300ex I just heated it with a heatgun, stretched it over and clamped it down.

Using the word "just" very loosely.. lol. It's a pain.

To disconnect the carb, I disconnect it at the front manifold boot like normal, then disconnect the rear airbox boot from the Airbox, leaving it on the Carb. Much easier than jacking with the airboot/carb connection.

Easy way to tell if it is a 400ex carb is if there's 2 vent lines that come up the to the top of the carb and then "Y" toghether into a single line.

[maddmatt02]

Ill have to go out and look again, but I remember one vent line coming off the top left and then looping over and dropping into where the black cover hides the linkages. and theres 2 coming off the bottom and they stay seperate. but unless a 250x boot is way smaller than a 300 its gotta be a 400 carb, becausew if you hook the bottom of the carbs lip inside the bottom of the boot, the top of the carbs lip is out further then the very outside of the boot, let alon sretching it to fit on the inside. Ill just get it on though and use it, I dont need it and it might be too much carb for my internally stock 300 and uni/DG. but after I finish it im getting a new frame to clean up and paint, and then im gonna swap everything over (its the old frame from the 330 my boss had and he cant title new one so he stil titles mine and I cant register mine....) and when i swap it over im gonna throw in a wiseco 11:1, web drop on or HC stg 1, and some mild porting, should take a little advantage of the big carb, even though it will stil be a 281. 330 kit is only about 200 more in parts, so I may do that, just depends on how money is at the time.

[dabomb_350x]

I believe all 300EX cloke levers are yellow, and so are the 400EX's, 250X's was black. The black covers are not shapped teh same either along with the different vent tubes.

[dabomb_350x]

I also believe that Honda changed the size of the carb on the 300ex. From a 28mm to a 32mm piston-valve with accelerator pump carburetor, around 98.

[maddmatt02]

before the change in size, was the 300 carb the same size as the 250x?

I do however have a 99EX carb, so I am going to get a larger air box boot off the newer 300's and maybe a newer manifold and see if it helps them, slide right in or not.

[bwamos]

Originally posted by maddmatt02
Ill have to go out and look again, but I remember one vent line coming off the top left and then looping over and dropping into where the black cover hides the linkages.

That's a 400 carb.

[maddmatt02]

alright, figured but was hoping maybe I had the larger carb from the newer ones, because the auction said 99 300ex, or even then would the housing be the same size but the internal bore be different. I got it into the manifold pretty easily, I think Ill just get the boot over it and hope to never take it off.

but another question. if I have a internally stock engine and just a UNI/no lid/full DG thats not enough to really see the potential of the bigger carb, but am I gonna see a major loss of low end with this huge carb on this tiny engine.

[beg2007]

on my 98 black and red 300 ex, it is YELLOW!

[maddmatt02]

but is there the vent line at the top that loops over and down into the throttle linkage assebly cover?