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Post Info TOPIC: Mikuni pumper carbs


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Mikuni pumper carbs
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Found this article whilst pondering carb options for the 350 (sorry guys, still twiddling my thumbs waiting for Woessner to get their act together...)

Contains a post from a certain TTRFAN. That you Brian?

Does anyone have any further info? Think this TM33 pumper carb can be used  on the DR350, which is in the right ballpark?

http://dirtrider.net/forums3/threads/ttr250-stroker-mikuni-pumper-carb.21061/

 

I was actually trying to find out if there is a larger TK pumper when I came across it. Gone off the idea of chinese-built flat-slides.

There's always the FI option I suppose (might be cheaper and easier to set up too!)

I know there's a thread on here somewhere about the TM32, which is not a pumper iirc.



-- Edited by mossproof on Wednesday 28th of February 2018 09:26:31 PM



-- Edited by mossproof on Wednesday 28th of February 2018 09:51:16 PM



-- Edited by mossproof on Thursday 1st of March 2018 03:07:58 PM

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Contains a post from a certain TTRFAN. That you Brian?

You been drinking cider???



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mossproof wrote:

Found this article whilst pondering carb options for the 350 (sorry guys, still twiddling my thumbs waiting for Woessner to get their act together...)

Contains a post from a certain TTRFAN. That you Brian?

Does anyone have any further info? Think this TM33 pumper carb can be used  on the DR350, which is in the right ballpark?

http://dirtrider.net/forums3/threads/ttr250-stroker-mikuni-pumper-carb.21061/

I was actually trying to find out if there is a larger TK pumper when I came across it. Gone off the idea of chinese-built flat-slides.

There's always the FI option I suppose (might be cheaper and easier to set up too!)

I know there's a thread on here somewhere about the TM32, which is not a pumper iirc.


It certainly was me Simon!

Some TM32 info here http://ttr250.activeboard.com/t53141894/fitting-a-mikuni-tm32/

Brian



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That thread is actually about the TM33P, which is the pumper carb and goes on to include the TM32 non pumper as well. It's a great read, and I'm seriously considering the TM33P for mine.

 I've spent way too much money on it already to stop now biggrin no



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Also been studying carb-boring, particularly oval boring, where the low throttle position is less affected, but airflow is increased in the upper reaches, which might be what I'm looking for to give good bottom/mid range but let the top end breathe better for power. Just seems that the 'States is the place to go to get these things done

https://thunderproducts.com/carburetor-boring-for-optimum-performance/


Also came across Dial-a-jet adjustable jetting kits, available for ttr250. Thunder Products seem to talk the talk?

thunderproducts.com/product-category/carburetion/dial-a-jet/dial-a-jet-dirt-bike/

Every day's a school day, but damn this internet thing burns time!



-- Edited by mossproof on Thursday 1st of March 2018 03:08:28 PM

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LOL dial a jet....
Re hash and old idea... didn't take of
in the 80..it won't fly now...



..


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I was looking at the Mikuni Oz site today.
They list a kit for the ttr250.

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Well spotted KMAN, that never used to be up on their site. They had info on the carb but not specifically for the TTR250.

Pasted off their website.....

Description
"Going fast has never been so easy. These carburetors have for a long time now been the popular carb of choice to fit to any 250cc or 300cc engine with allowable space, where chasing optimum increases in performance and power along with general smooth throttle response and ride-ability, with the nothing short of outstanding results when fitted to your Yamaha TTR250.

These Mikuni carburetors are compatible size matched for your Yamaha TTR250 air box boot and intake manifold rubber flange. For carb clearance the motorcycle’s top frame bracket requires a little material to be removed and the rear brake fluid reservoir slightly relocated by bending the mounting bracket. The kit comes with throttle cables and a 1/4 turn quick action throttle as the Yamaha cables come up short on overall length. There are jets provided where the pilot may require fitting if your engine does run a little rich and the new middle size main jet must be fitted with an additional one up and one down size supplied for perfect main jet size conformation when doing WOT test runs.

Climate, altitude and fuel density from different octane fuels all may have varying effects on final fine tuning as does cam, exhaust and cylinder head porting etc. For this reason we strongly suggest checking the tune as per the supplied instructions to maybe even get more performance than initially experienced.

This kit includes a TM33 -8012 carburetor, a pair of cables and qu With the bonus I've been after a quick pull throttle.ick action throttle, a pilot and three main jets for tuning."

I'm very tempted by this,have been thinking about it for my 263 engine for a while.

For the 350 you'd probably go bigger??



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If i can find a replacement jet for my standard carb i might try this later on

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I've recently bored out my STD carb and going to try that first. I simply hogged it out with a die grinder and finished with sandpaper roll. If it doesn't work well enough I was going to try a dr350 carb next or Koso 32mm Chinese version of pwk kehin. I've used those with success before on other bikes.
Si

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That's good to know......

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