Yamaha TT500 XT500 SR500 FCR carb
Posted January 30, 2009 - 09:50 PM
Best carb for that bike is from sudco 38mm round slide
just because that's what everyone is using including me doesn't mean that's the best carb for the bike . If it was still 1980 I would agree but it's 2009 and I think carbs have progressed beyond the 38VM round slide or at least I hope they have? but then again things have progressed beyond the 500 Yamaha but that's another thread.
So anyone tried the FCR on these bikes ? I'm thinking a 37mm should do the trick? I'm just not sure jetting wise how far off a 37mm carb from a liquid cooled 250 would be from an air cooled 500 ?
How would you make it fit?
I'm sure it will bolt up maybe with a K&N filter but where there is a will there is a way.
Posted January 31, 2009 - 07:26 AM
I was considering this switch for the same reasons, but it really looks big to fit on a TT500. The top of the carb has a lot going on with all of the throttle actuation gizmos. I will be jealous if you make it fit.
I ended up with a Dellorto 38 pumper, a common mod for flattrackers when they raced these bikes.
Posted March 13, 2009 - 07:29 PM
I hope you don't take this as being disrespectful, but you have it backwards by putting it on Yahoo first.
Posted March 16, 2009 - 04:44 AM
No disrespect taken but there was no divine intervention that told me that there was a group already supporting Thumpers so I started my group. I will not be closing my group, it is just for TT/XT500s. This site covers a lot of different thumpers and I have only been with all of you just a short time I am still having trouble sorting through all of the information. I hope to get better at it.
Posted March 16, 2009 - 08:11 AM
I hate having to register for everything.
Might I recommend http://bugmenot.com. This is a site that keeps a database of bogus user names and passwords so you don't have to register for everything to view one little item of interest.
Posted April 02, 2009 - 06:59 PM
This carb is one from a YFZ450 ATV so it only uses the single pull cable. Don't quote me on the intake boot but i think it is from a ZX9 2001ish . Best to go to the local wrecker with your new carb and your old intake in hand. The carb is a bit shorter than the stocker so something will need to be done to pull the air box connecting boot forward or make it longer. Or one of the older carbs with the removable bell on the back might be the way to go and make your own bell if you have the resources for that kind of thing.
To make a little extra clearance at the tank bottom/carb top, I added about 4 washers under the rear tank mount and used a longer bolt . The carb is also mounted on a very slight angle not much at all really. The oil line is the biggest pain , but it's not in the way of anything the way I have it and with some fiddling there might be other ways to run it.
The fuel line is fine as well the choke/hot start would be easy access ?
This bike is unfortunately not one of my runners, so I was just using it as mock up. It might run but this engine is a complete unknown to me so I would hate to spend much time trying to tune the carb on this engine. I'll have a fresh engine in my daily driver in the next few months then I'll swap all this over to that bike. But it looks like this is all possible. This only took me about an hour and a half and I'm using the stock cable.
Posted April 03, 2009 - 03:29 AM
we made a sleeve on the boot side bell to fit (well-documented on dr forum & you can see in my garage on the dr650 bike)
its a 39mm, a 35-37mm might be best for the xt500.
a flatslide pumper is the poop man. not just for best performance, excellent throttle control & smooth pulling throughout the rpm range, including low-end.
Posted April 03, 2009 - 05:05 AM
Posted May 13, 2011 - 07:02 PM
Posted May 13, 2011 - 08:08 PM
i have a tt500 deraked flattracker,90 mm carb,powroll 7 mm stroked engine,ported,vance hines ss2r slipon from an r-6,ard ignition,pipe,megacycle cam,heavy valve springs. i put an fcr from a wr400,i believe a 39 fcr carb. not sure of jetting. had to shorten intake manifold to almost nothing to get it to clear frame,maybe 3/16" thick thick. what a big difference from a 38 round mikuni. i changed carb and now you get a kick in the ass about half way into the rpm's,and revs longer. you might lose just a touch right on the bottom,but it is such a great carb. go figure,all the new mx bikes run them,it is not an accident that they do!
Good to know:thumbsup:
Iv'e also had found that a newer style of 2-st carb replacing the old vm38 on my vintage racer made it run like a new bike.