Pumper carb for KLX300

[Marklx]

Called Stroker the other day, and asked that question as old as time; which pumper?

Their response was that it depended on where and how you ride. For forest, technical type work, get the 33mm. For flat out Socal and track type riding, get the 35mm.

He felt that the 33 would run out of steam for the wide open type trails out here in Socal. Loves the way it works, just felt that the loss of 1mm would be felt if you frequently end up in 6th gear. So that's the direction I'm going, as I am often in 6th, and often on tracks. Figure for technical rides, can always slap the cvk back on. It works pretty well, and is very forgiving of my careless ways.

Should receive my 35mm today, revalved forks next week, and a sizzling visa bill next month.

Mark

 

[penguin]

Yep, thats what I have posted more than once, more bottom end from the 33 more top end from the 35 FCR or 36 Mikuni. actually the FCR from a pure performance viewpoint is the best carb, but it has inconsistent and sometimes horrible hot start behavior, which is why I am going with the 33. Trust me, I have run them all, and I did not notice any weakness on top end with any of the 3 carbs, you might gain 500 rpm on top with the FCR, but I am not astute enough to notice it..

 

[Sierra Flash]

Pumper Carbs

you sound like an aggressive rider so the 35MM will be far better for what you do. If you want to slug around you can use the CV as you stated but doubt that you will ever change back. The FCR's are easy to start when you get use to them, even if you fall over.

 

[DougRoost]

As you know I put the 33mm Mikuni on my bike and really like it. I did this after talking to both Penguin and Dave in Stroker's tech department. You know what Penguin said (and he's right), so I'll tell you what Dave told me back in June.

At that time Stroker was revisiting the 36mm Mikuni, mainly because the 33's were on backorder. Also the FCR is a pretty expensive and somewhat finicky carb. Larry's newest KLX is running a Mikuni 36 and he ran hundreds of trouble free miles in Mexico with it. Said for the top end power this is a great carb, though you do give up some low end compared to the Mikuni 33. Also noted this is the way to go if you plan to move up to their 365 motor (you won't have to replace the 33 with the 36). You should also know XR's Only uses Mikuni 36s for their XR400 pumper carb conversions.

That said, the YZF/WRF, KTM RFS, and Honda CRF all use Keihin FCRs. Given your high speed use you should be happy with it, but I wanted to share this info for other folks looking at pumper carbs because it is quite a bit of money. Do be careful about cleaning the accelerator pump shaft, or better yet protecting it with a shield ala KTM, as it is exposed and can get restricted by mud.

 

[Marklx]

Tom, and other FCR users,

Since you've run 'em all, maybe you can help me out with this...
Just received the carb five minutes ago, and curious about the air box adaptor on it. It is a Sudco piece, about an inch and half long (in the stroker picture, it is much shorter?). The inside diameter of the adaptor doesn't match that of the carb at the top, overlapping the top of the carb by about 3/8". I'm concered that the i.d. is so much larger,(sort of looks like a crescent moon) and is an abrupt transition to the carburetor taper.The bottom matches perfectly. The o.d. of the adaptor is 58mm which I assume fits the stock boot properly. .

Hope this makes sense, and that it is the same for all you other fcr users.

Mark