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32mm FCR CARB from CRF150R

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Anybody ever check a 32mm FCR pumper carb for the 230?

Physically won't fit with the frame proximity??

Just curious if it's been tried ...

I have a lot of experience tuning the FCR carbs and in my experience no other carb comes close the the tunability and performance characteristics of the FCR carbs for 4stroke engines...

Adapters would not be a problem.... I dont know if any of you know of Sredrum Performance, but Chris is the absolute best , fanatic to the bone machinist I have ever known... He does carb and throttle body taper boring and makes his own billet FCR center rings with extra meat to allow boring to over 44mm on the 450 carbs...

The second dynojet I owned resides in his shop :)... He works full time as a machinist for Chrysler... And more than full time in his Sredrum Performance shop...

Anyways... Since I am fortunate enough to have him as a friend I would consider having some billet adapters made as well as some.custom taperbore FCR carbs...

 

But before I ponder much longer... I wanted to know if anyone had checked that avenue out...

Edited by mixxer

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Have used big FCR on other bike motors (XR460, TT628 ETC) yes they are awesome but physical  size has always been issue. Nearly the size of a Carter AFB for cars. PWK carbs are very small outside dimensions compared to even the stock carb. Am positive a well built 230 will easily pull a 32 as have had hot 218-240 XR200 pull them well. Have not had much time to learn tuning on FCR so always will appreciate help in the future.

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Yes, not sure of the OP's name but he used to be a regular contributor to the forum. I think he was from France or Italy? Maybe his handle was "La Frenchy" or something like that? The frame has to be modified to make it fit.
He had it installed and running but I'm not sure he ever got it jetted the way that he liked?

He also played around with a Tokyo Mods digital, programmable advance curve Ignition system for the air cooled 2005 or older 150f engines but since a 230 has electric start, he didn't get to far with that. About that time the Pro Com was discovered so that killed it even more.

I think it was "Baja" that purchased the same brand ignition system, never used it, and was trying to sell it?

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I knew you guys would know...

Thanks for the input...

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Have used big FCR on other bike motors (XR460, TT628 ETC) yes they are awesome but physical  size has always been issue. Nearly the size of a Carter AFB for cars. PWK carbs are very small outside dimensions compared to even the stock carb. Am positive a well built 230 will easily pull a 32 as have had hot 218-240 XR200 pull them well. Have not had much time to learn tuning on FCR so always will appreciate help in the future.


My EO 247 has had a 32 flat slide on it since 2005
Stock stroke and the stage 3 EO cam is a torque cam with more lift than stock guides can handle. (A Coe MC-1 Cam is more powerful and makes just as much torque)

The 32 has always worked exceptionally well. This engine is a kick start and the bike starts very easy and consistent with the 32.
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Very interesting thread ..

Vortec, thank you for the link!

Mention was made of modding the frame at 2 points to mount the carb..

Also mentioned was how much stronger the initial pull was with the FCR... That has been my experience with FCR swaps on trx450s...

The 04 05 models have a 42mm non FCR carb that is still an accelerator pump carb... Swapping to a 40mm FCR carb adds bottom to mid response like a good big bore kit... And has same top end power as the 42mm OEM carb...

A bigger difference than can be conveyed without riding one...

I was against the swap on my trx... Until I rode one with the FCR carb... Ordered mine the Monday after...

 

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A PWK 28 swap would be easier and cheaper.

The Throttle Position Sensor (TPS) on the FCU for 3D spark lead vs 2D lead for RPM only spark lead. The TPS is used to indicate throttle position and to add extra spark lead to compensate for lower compression pressure ( and ignition burn rate) at higher manifold vacuums of part throttle. That even hurt my brain. 

Anyway the net result is the extra spark lead improves power and fuel economy at part throttle, what you feel is improved throttle response. :thumbsup: On my CRF250X I disconnect the TPS for low traction riding situations to make the throttle feel more like a XR.

With TPS, or a Manifold Absolute Pressure (MAP),  and an aftermarket programmable ECU like Microsquirt I could increase part throttle spark lead to improve part throttle power, mileage, and throttle response.  Could be more than you want for technical trail riding.

Edited by Chuck.
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8 hours ago, Chuck. said:

A PWK 28 swap would be easier and cheaper.

The Throttle Position Sensor (TPS) on the FCU for 3D spark lead vs 2D lead for RPM only spark lead. The TPS is used to indicate throttle position and to add extra spark lead to compensate for lower compression pressure ( and ignition burn rate) at higher manifold vacuums of part throttle. That even hurt my brain. 

Anyway the net result is the extra spark lead improves power and fuel economy at part throttle, what you feel is improved throttle response. :thumbsup: On my CRF250X I disconnect the TPS for low traction riding situations to make the throttle feel more like a XR.

With TPS, or a Manifold Absolute Pressure (MAP),  and an aftermarket programmable ECU like Microsquirt I could increase part throttle spark lead to improve part throttle power, mileage, and throttle response.  Could be more than you want for technical trail riding.

This is very similar to the purpose of vacuum advance on old ignitions.  Spark lead was increased during high-vacuum driving (i.e., small loads and/or small throttle positions which result in very low cylinder pressure).  During low-vacuum driving spark lead reverted to that dictated by the mechanical advance alone.

Hi-Po vehicles (like boats and race cars) do not need a vacuum advance because they rarely operate at partial throttle positions or are always operating under a very big load with high cylinder pressure, just like our old-school dirt bikes.

Removal of vacuum advance on a street car results in lazy sloppy throttle feel, larger throttle openings for the same speed, lousy fuel economy, and a very crappy burn.  IC engines require a lot of spark lead when operating with very low cylinder pressure.

A vacuum advance is sort of like a MAP sensor or cylinder pressure sensor.  Very crude but very effective.

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Another yes vote for FCR carbs. An FCR40 is the best single mod you can do to a DR650. It pulls smoother and stronger 1000 rpm lower than the stocker and completely changes the personality of the bike. And that's without the TPS hooked up. I think their low RPM performance is a good match for a torquey motor. They are bulky so even the smaller 32 won't fit in my BBR framed bike. 

I think the FCR32 will work well on a modded 230.

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