Author Topic: FZR carb conversion  (Read 29742 times)

Walt_M.

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Re: FZR carb conversion
« Reply #180 on: September 15, 2018, 07:59:37 AM »
I haven't had any problems that I could relate to float level.
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fret not

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Re: FZR carb conversion
« Reply #181 on: September 15, 2018, 12:50:40 PM »
That is my point, and thanks Walt.
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fret not

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Re: FZR carb conversion
« Reply #182 on: September 18, 2018, 03:38:14 AM »
If the carbs are not negatively effected by standing them straight up then the original air box (as YOU point out) should not need much if any modifications.  With the carbs from the YZF600r that I am using I chose the pair that has the bell crank and left them connected together as they were in their original application.  This caused me to make up new manifolds to fit the carbs.  It is MUCH easier to use original manifolds than it is to make new ones, but I didn't have to fabricate linkages and such between the carbs.  Since I have a spare air box I will modify one to accommodate the "new" carbs. 
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

injuhneer

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Re: FZR carb conversion
« Reply #183 on: July 01, 2019, 10:58:46 AM »
People are pretty brave on pricing Vmax carbs while I have found FZR600 carbs around $100-125. And, as I found out, the first and third carbs were best for my purposes. Another benefit of this conversion, since I no longer have the airbox flapper, I have hardly any oil in the airbox from the crankcase vent, which makes perfect sense when you think about it

You can buy a rack of (V4) Venture carbs for a lot less than VMax carbs. They are nearly identical. VMax folks use the Venture carb bodies as spares.
Here is a thread:

http://ridersofvision.net/rovforum/index.php?topic=15881.0


Now I am wondering if a 2 cylinder version of V-Boost would work...
« Last Edit: July 03, 2019, 08:24:36 PM by injuhneer »
- Mike O
injuhneer
1982 Yamaha XZ550RJ
--------------------------------------------
1975 Honda ST-90 (164cc stroker)
1972 Kaw GT4R
1978 Kaw KM100
2008 KTM 450 SXF

livetoride21

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Re: FZR carb conversion
« Reply #184 on: April 16, 2020, 10:22:06 PM »
Just read through this whole thread, nice work!
I just picked up an first year Vision 550 and will be building a vintage race bike out of it.
The FCR carb conversion is very attactive for me because I already have a rack in stock!
Curious, what jetting did you end up at? I saw 32.5 pilot, 127.5 main, and 52.5 starter, is that correct? Did you ever do a plug chop?

thanks!
Hope you're still here on the forum.

Kevin

fret not

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Re: FZR carb conversion
« Reply #185 on: April 17, 2020, 03:39:09 AM »
I just left the jets that were in the FCR carbs in place as they should be within the ball park if they are stock, which I believe they are.  Hopefully this will be a good starting point for fine tuning.  Also, it may be some time before I actually run the bike to find out as there are some other areas that need attention before that can happen.
« Last Edit: April 17, 2020, 03:50:29 AM by fret not »
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

livetoride21

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Re: FZR carb conversion
« Reply #186 on: April 17, 2020, 06:37:10 PM »
Thanks for the reply back Fret not.
I actually slipped up and had FCR on my mind, but meant to write "FZR" as in the FZR600 carburetors.
Hoping Walt can shed some light on it.


Walt_M.

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Re: FZR carb conversion
« Reply #187 on: April 18, 2020, 07:07:25 AM »
Yes, that's where I left the jetting. I never did do a plug chop as it ran pretty good there. Just a thought if you're thinking of track time, I believe it lost some power on top due to the smaller bore. but it could be the jetting.
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livetoride21

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Re: FZR carb conversion
« Reply #188 on: April 18, 2020, 09:01:11 PM »
Thanks for the reply Walt! I'll try it out. I have them in stock, so it be worth while to test.
Will try it out with your jetting and see what it nets. As far as losing power on top, I wonder how much air these motors can really pump through 34mm bore? I mean I have-to figure if two 41mm are enough to feed my 944cc ducati, two 34mm carbs should be adequate to feed the 550 up top.
Have you ever tried YZF600 (thundercat) carbs? I believe they're slightly larger bore, but very similar.

fret not

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Re: FZR carb conversion
« Reply #189 on: April 19, 2020, 10:54:21 PM »
Yes, that is what I have.  From a YZF600R Thunder Cat.  Made by Kehin, and they have nice long trumpets.  As I recall, Tree Dragon said he put another set of the rubber boots in the airbox to lengthen that intake and smooth the air.  He reported it made a noticeable difference.  I miss his participation here, he had some good "tales" to tell about his marvelously developed bike.
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

livetoride21

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Re: FZR carb conversion
« Reply #190 on: April 20, 2020, 08:28:57 AM »
Interesting, for some reason I thought you had put fcrs ( flat slide non cv carbs)
Thanks for the reply, you said youre running the stock thundercat jetting?

fret not

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Re: FZR carb conversion
« Reply #191 on: April 21, 2020, 12:45:24 AM »
Not running yet, still in the "project" stage.
Retired, on the downhill slide. . . . . . . . still feels like going uphill!