Found a set of carbs -

[FJ1200W]

Thoughts on using these on a 1989 FJ1200?









Randy's pods fit?

I believe they were set up for alcohol so the jets needs to be checked.

Clean as a whistle.

[Pat Conlon]

Randy can order UniPods that fit....they make several different sizes.
The air filters are the least of your worries....

Just to get started: Did these carbs come off a FJ?

IOW is the spacing (77-85-77) correct to fit the FJ intakes?

[balky1]

Geez, what did these things came off from? A Zero? 

[ribbert]

Thoughts on using these on a 1989 FJ1200?

Even if they bolt straight up, why?

Presumeably they are not inexpensive and even if they're free, what improvement are you hoping to achieve? The FJ's already have efficient, uncomplicated carbies that do a very good job, why complicate things and for what gain?

You asked for thoughts, these are mine.

IMO

Noel

[FJ1200W]

Randy can order UniPods that fit....they make several different sizes.
The air filters are the least of your worries....

Just to get started: Did these carbs come off a FJ?

IOW is the spacing (77-85-77) correct to fit the FJ intakes?

Yes, these are for the FJ series motorcycles.

Appears to be pretty much a bolt on operation, and then jetting them properly, of course.

The reason I would put them on - I tend to enjoy a street race every once and awhile. The FJ is a great sleeper, with some more power, it will be an even better one.

[FJ1200W]

Thoughts on using these on a 1989 FJ1200?

Even if they bolt straight up, why?

Presumeably they are not inexpensive and even if they're free, what improvement are you hoping to achieve? The FJ's already have efficient, uncomplicated carbies that do a very good job, why complicate things and for what gain?

You asked for thoughts, these are mine.

IMO

Noel

These flat slides are far simpler than the CV carbs on the FJ now, but that's not why - Power, POWER - that's why.

Several weeks ago, I was in a street race on some country roads, and it was against, of all things, a Harley.

A highly modified Harley.

The first little run we had, I took him, but not by much.

The second run, he pulled me by about 2 bike lengths.

That is something I will not allow to ever happen again.

I know some of you may frown on this type of immature behaviour, and I'm good with that.

You ride your ride - and I'll ride mine.

Other than these carbs, there are a few other things that I might throw at my bike.

There is a 1315cc built motor sitting in my last remaining storage area, that's a last resort......

More to come

[ribbert]

I know some of you may frown on this type of immature behaviour....

Why would you think that?  Growing old disgracefully and being immature when you can get away it I would have thought were common traits around here. This is a wowser free zone.

Noel

[JPaganel]

The FJ's already have efficient, uncomplicated carbies

[Flynt]

They look like 38mm vs the stock 36mm, so there is more flow capacity available.  To get improved performance out of them, you'll need to improve the flow capability of the engine and get them properly tuned (on a dyno).  You're also trading off the CV benefit of the stock carbs which allows them to run well in a wider range of temperatures and altitudes.

My '92 (Wizard) has 1350cc, mild cams, akrapovic exhaust, and 39mm flatsides.  At sea level and ~85 degrees F, it is a scary fast SOB.  Anything else and it's not optimal, although still pretty damned good.  If I go above ~3,000ft it is noticeably losing power..  If the temp is below 65 F, it runs so rich I don't ride it.  Some (Flatside Frank East for example) will adjust and even re-jet for the various conditions.  I just ride the '84 with the CV carbs more in these conditions.

I'd be careful what you do to the stock setup which is very well balanced.  You might find that tuning your stock carbs with pods and a decent exhaust will produce quite a bit more power than you have today...  especially getting the mains right since they are small to start with and it gets worse if you change exhaust and ditch the airbox. 

YMMV, but the flat side conversion isn't something to be taken on lightly...  especially if you're at all worried about carb tuning and associated expense.  There are probably several ponies hiding in the carbs you have, unless they've already been thoroughly cleaned and tuned for max power at WOT.

Frank

[aviationfred]

I am by no means a carburetor expert. In fact I will admit that I am still a novice when it comes to carburetors and their adjustments.

With that said. I have heard almost the exact story from others that Frank is saying. Flat Slide carbs need constant adjustments. If that is what you want, by all means, go for it.

When my engine grew to 1297cc's. I knew that my carbs were going to need major adjustments. I sent them off to be completely rebuilt and have a bench adjustment based on my mods and elevation. The OEM CV carbs were so wore out, that the rebuild cost was prohibitive and I purchased a Brand new set of 36mm CV carbs with the all stainless steel screw kit. It also came with adjustable needles. I find the adjustable needles as being the best benefit. When I ride to Colorado and am constantly riding 5-6 or 7 thousand feet higher elevation. I can quickly and very easily move the needle clips one or two positions and the bike will perform much better at those altitudes. No messing with jets, no removing the carbs, etc.

From your post.... My thoughts are....you are looking for that ultimate sleeper bike. Put the 1315cc motor in, get your OEM 36mm CV carbs rebuilt and jetted properly to the 1315cc engine, and keep the FJ1200 decals. FWIW, just my 2 cents.


Fred

[fj1289]

I've used the flatslide Mikuni carbs on fairly stock and modified FJ1200's.  If you can get a god deal on them - go for it.  If you decide you don't like them you'll be able to recover most (if not all) of your money. 

I do not like them for a daily driver - the slides tend to "stick" a bit at low throttle settings and make it difficult sometimes to smoothly add power - like exiting a turn.  They can also "stick" a bit at WOT and you have to "pull" them closed - or set the return spring to a very stiff setting.  I loved the set of Keihin FCR's I had - the rollers on the slides really made a big difference in how well they behaved.  They are a bit more involved to get jetted properly though. 

If you have a good flowing exhaust, you will see some gains - not a lot if everything else is stock, but something you can "grow into" with future mods. 

My personal observations - the exhaust is the biggest limiter, followed by carbs, then head and valve train.  No matter what you do, if you have old tired valve springs in it, you're losing power up top. 

As with any engine mods - the "sharper" the engine build, the narrower the tuning band is and the easier it is to "fall off" of the added performance if the tuning is not spot on. 

[FJ1200W]

Thanks for the replies, lots of good information.

I have the carburetors in a box with many other parts, so their paid for - wanting to do something with them.

Today I was blessed with this for part of the afternoon -



It's a new old stock 2015 Kawasaki ZX10R with less than 200 miles on it.

We added a Power Commander V, the proper map. The Yoshimura slip on connected to a titanium Akrapovič link pipe (eliminated the exhaust controls and cat). It had a reverse gear shift - 1 up and 5 down. Oh my gosh did it have power, if you've never ridden something like it and you get the chance, try it. Real eye-opener, street legal 9 second bike, just stupid fast. Way too small for me (6'4"), I could never own one.

But I'll ride them any chance I get!

[giantkiller]

Thanks for the replies, lots of good information.

I have the carburetors in a box with many other parts, so their paid for - wanting to do something with them.

Today I was blessed with this for part of the afternoon -



It's a new old stock 2015 Kawasaki ZX10R with less than 200 miles on it.

We added a Power Commander V, the proper map. The Yoshimura slip on connected to a titanium Akrapovič link pipe (eliminated the exhaust controls and cat). It had a reverse gear shift - 1 up and 5 down. Oh my gosh did it have power, if you've never ridden something like it and you get the chance, try it. Real eye-opener, street legal 9 second bike, just stupid fast. Way too small for me (6'4"), I could never own one.

But I'll ride them any chance I get!

Just like my nephew's. He bought it as soon as he got home to Golden. After riding my 1350. He's an extreme skier. And instructor.(frickin retarded) Not to crazy on the bike yet. I think it's a little too much money to chance throwing it away.

[JMR]

 I have run RS 36, 38 and 40 on my FJ with different engine exhaust combinations. Biggest negative is s stiff return spring. I currently run FCR's which are nice but no cold start system. The RS's bolt on and you can hook up the "choke" cable. The throttle cable ends need to be straightened a bit but they go right on. The FCR's required different cables and I had to modify the cable holder on the carbs.
Only real tuning issue I have had with RS's is getting the accelerator pump adjusted correctly (you can adjust when it is activated and the duration of the shot). I have always used K&N filters. The FJ side covers form a nice "air box" and protect them from rain.
I have put many thousands of miles on RS carbs with no issues. And they do increase HP

[FJ1200W]

I have run RS 36, 38 and 40 on my FJ with different engine exhaust combinations. Biggest negative is s stiff return spring. I currently run FCR's which are nice but no cold start system. The RS's bolt on and you can hook up the "choke" cable. The throttle cable ends need to be straightened a bit but they go right on. The FCR's required different cables and I had to modify the cable holder on the carbs.
Only real tuning issue I have had with RS's is getting the accelerator pump adjusted correctly (you can adjust when it is activated and the duration of the shot). I have always used K&N filters. The FJ side covers form a nice "air box" and protect them from rain.
I have put many thousands of miles on RS carbs with no issues. And they do increase HP

That is good to hear. Thank you.