Author Topic: FZR carb conversion  (Read 29743 times)

Ron_McCoy

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Re: FZR carb conversion
« Reply #120 on: September 20, 2016, 10:55:03 PM »
Have to add that elevation where I live is right at 4000 ft. 20 miles west its down to 600 ft and same distance east around 2500 ft.

Walt_M.

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Re: FZR carb conversion
« Reply #121 on: September 21, 2016, 06:05:39 AM »
Ron I was very surprised to see your jetting numbers, especially now that I see your elevation. I am at sea level and it was really rich with 130 mains but I also had 75 starter jets and 40 pilots. I went to 127.5 mains, the 62.5 starters and 32.5 pilots that came in the carbs and it is running pretty good now except for the idle. So, having just gone over what I wrote, it looks like my problem was the 75 starter jets. Looks like plug checks are in order but it is still hot here in Florida so that is not much fun.
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Ron_McCoy

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Re: FZR carb conversion
« Reply #122 on: September 21, 2016, 09:16:30 AM »
Walt, I started with 127.5 mains and 32.5 pilots  and 52.5 starter jets and worked from there. Still hot in California too. Going riding with friend this morning. Should ,at least get gas mileage info today.

Walt_M.

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Re: FZR carb conversion
« Reply #123 on: September 21, 2016, 04:53:41 PM »
Got a better set of eyes on my starter jets and they are 52.5 so we are together there. Went ahead and changed my sparkplugs so I will be ready for a plug check. I forgot to ask what exhaust you have, I have a Spec II on mine. When I got it 30 years ago, they recommended no jetting changes and it didn't seem to need any.
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Ron_McCoy

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Re: FZR carb conversion
« Reply #124 on: September 21, 2016, 05:10:56 PM »
I thought about the exhaust after I left this morning. Mine is one I built several years ago, basically a 4 into 2 into one much like a Spec ll with a muffler I built too.  I rode 140 miles today. Put gas in after the first 58 miles which was mostly an all out race with a couple of 2016 R 1200 RT BMWs over a twisty mountain road with a lot of elevation change. That worked out to right at 45 mpg. After a less aggressive ride down Kern River Canyon and back to Tehachapi, the next check worked out to an even 50 mpg. Best I've ever gotten with a Vision.

fret not

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Re: FZR carb conversion
« Reply #125 on: September 22, 2016, 01:26:13 AM »
Ron, I am assuming you have Mikuni carbs, like Walt has.

This is getting good. 
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

Ron_McCoy

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Re: FZR carb conversion
« Reply #126 on: September 22, 2016, 01:15:01 PM »
Mike, same carbs as Walt.

Ron_McCoy

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Re: FZR carb conversion
« Reply #127 on: November 05, 2016, 01:36:42 PM »
Some pictures.

Ron_McCoy

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Re: FZR carb conversion
« Reply #128 on: November 05, 2016, 01:42:55 PM »
More pics. Jetting now: 130 main jets, 32.5 pilot jets, 52.5 starter jets. Starts right up, excellent throttle response, mileage  in the 50s. Runs so good it seems even more low geared even with Euro gearing. Really happy with this mod. I wish I had finished this years ago.
« Last Edit: November 17, 2017, 11:17:44 PM by Ron_McCoy »

Ron_McCoy

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Re: FZR carb conversion
« Reply #129 on: November 05, 2016, 01:44:56 PM »
More pics

jefferson

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Re: FZR carb conversion
« Reply #130 on: November 07, 2016, 10:53:07 PM »
Can you guys explain to me the starter jet you are talking about and where it is on the carb? Is it's purpose for when the choke is on?
I was relaying your jetting specs to the friend of mine who used vmax carbs on his bike which I think are also 34mm and both of us were a little stumped on the starter jet. I was thinking that the jetting should come out about the same since they are both 34's, but you never know. He thinks his pilots are up around 60 although his mains are the same as yours.
The main difference seems to be the vmax carbs just needed to be spread apart more to fit and they fit right into the manifolds. He took them off when he was having running problems and reinstalled the stockers. That really didn't fix anything and it turned out one of his plugs had gone bad. If he gets the vmax setup back on the bike it may run much better now.

Walt_M.

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Re: FZR carb conversion
« Reply #131 on: November 08, 2016, 04:01:15 AM »
The starter jet is in the float bowl in the BDST carb. There is what I call a jet tower and it has the main, pilot and starter jet. I believe the starter jet is what feeds the richening circuit but I have not followed the plumbing to be sure. I had not considered vmax carbs but I guess I should have. The FZR carbs do not fit the manifolds but even if they did, they will not clear the cylinder head.
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fret not

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Re: FZR carb conversion
« Reply #132 on: November 10, 2016, 02:10:21 AM »
Ron, your pictures are inspiring.  I am about half way to making the 'new' carbs fit my '82, though I have got side tracked with other more important stuff.  Life happens while you're making other plans, but I hope to have more time in the shop by mid January or so.

I got different carbs from you and Walt, mine came from a YZF600r Thundercat (Kehin 36mm), and have longish intake trumpets.  This takes up a bit more room than the shorter front carbs you guys have.  So I empathize with Walt's comment regarding the tight quarters for fitting these things.
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

Ron_McCoy

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Re: FZR carb conversion
« Reply #133 on: November 10, 2016, 01:46:35 PM »
Mike,
I know what you mean. i had to take a long break on thi.s project my self.

I'm not familiar with the carbs you have. One thing that helped with the mikunis was to grind clearance for the rear float bowl in the head stay from the rear head to the frame to allow the carbs to sit lower, closer to the head. It's definitely a tight fit. Setting up the cable stops, linkage, and plumbing can take some patience, but it's worth it. It's like a whole new bike, much less finicky.
Best of luck,
    Ron


Walt_M.

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Re: FZR carb conversion
« Reply #134 on: November 12, 2016, 02:24:22 PM »
Ron, I just noticed you have a different fork on your bike. What is it and what is the offset of the triple clamps?
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fiat-doctor

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Re: FZR carb conversion
« Reply #135 on: November 13, 2016, 10:39:18 AM »
Great work both of you!  I just wanted to say what a great inspiration you are to all of us and also by sharing the info on jetting, that you have learned along the way you have made the job that much easier for those who follow your path. Steve

Ron_McCoy

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Re: FZR carb conversion
« Reply #136 on: November 15, 2016, 11:28:17 PM »
Walt, the forks are from a Kawasaki ZZR1200. The offset is 2.30 inches center of steering stem to tube centerline.

fret not

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Re: FZR carb conversion
« Reply #137 on: November 16, 2016, 12:41:33 AM »
Looking good, Ron.  Did you have any clearance issues with banging into the radiator or tank?
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

Ron_McCoy

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Re: FZR carb conversion
« Reply #138 on: November 16, 2016, 01:31:18 PM »
Mike, had to make my own steering stops anyway so no problems with hitting tank or radiator. It has plenty of turning lock.

fret not

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Re: FZR carb conversion
« Reply #139 on: November 17, 2016, 01:28:45 AM »
That's good to know.  How do you like the handling with the 'new' front end?
Retired, on the downhill slide. . . . . . . . still feels like going uphill!