Replacement carburetors for XS650?

[lakeview]

Thank you

 

[5twins]

I think the 750 uses BS32s or 34s. I know the alloy tops are a direct swap for the tin tops on our BS34s, a nice little upgrade. The floats and float bowls, maybe the float needle assemblies too, may swap onto the BS38s but I can't say for 100% sure.

 

[XSLeo]

Did some looking around. The XS750 used 3 34 mm CV carbs. From the pics in the parts fiche at boats.net they look about the same as the XS650 78-79 carbs.
In 77 the carb parts numbers where
1J7-140901-01-00 this is the left carb.
1J7-140902-01-00 is the center carb.
1J7-140903-01-00 is the right carb.
In 78 the listed just two part numbers.
2F3-140901-00-00 left the other two are 2F3-140902-00-00.
How well they might adapt to the XS650 is anybodies guess.
Leo

 

[1974jh5]

I *think* the alloy top BS34's that were on my bike were XS750 carbs. The only odd thing was that when I got them there were only two and they were linked by a steel bracket just like the 650's but was shorter. It did not appear to have been cut. I swapped the throttle shafts, etc and used the 650's link bracket and butterfly brace.

 

[5twins]

If it was just a pair then they could have come from an XS400. Did they have 5Z1 needles?

 

[1974jh5]

It's very possible they did. They have gone to the great carburetor graveyard in the sky so no way to know for sure.

 

[jim540]

Here are some shots of the air filter in place.

 

[54inches]

I found that with an oil cooler the head and cylinder temps drop about 40-50 degrees and evens the left right to less than 5 degrees.
When running one carb the cooler will balance the cylinder temps.
Leo

What cooler are you running?

 

[XSLeo]

It came off the 82 Seca 650 turbo parts bike I have. It's the same size and looks a lot like the one Mike's sells. The way the lines hook on is a bit different.
The one Mike's sells is a good price for one.
If you search ebay you can find them. Most any cooler from most any bike can be adapted.
Pics, first row is the second cover mod, much cleaner look. Second row is one of cooler on bike, one extra oil filter, one of first side cover mod.
Leo

 

[jim540]

Here is the latest picture of the bike with the single carburetor and new fuel tank.

 

[jim540]

Here's a couple more pictures.

 

[5twins]

Where's your leg go now, lol.

 

[jim540]

It is deceiving actually. When you look at the picture it looks like the carburetor will be right where your leg goes. It sits right under your left knee. When I first put it on the bike I though oh crap, I'm going to need a set of forward controls.

 

[jim540]

Oh my gosh!!! Got the bike running today with the Mikuni VM carburetor, Joe Wiseguy intake and new small Sportster tank. The engine fired up on the second or third kick. Could not believe how easy it fired. The idle was around 2000 RPM. Reached down and dialed the idle down to around 1500, then adjusted the idle air jet to smooth it out. Sounds so cool, like it's got a cam in it or something. Had to take it for a quick ride around the block, I say quick because it's around 40 degrees out. Man this thing has never run this good. Has a completely different sound than it did with the dual carburetors. Needless to say I love it. Wow!

Here is a link for a video I took after I got it running. Hopefully it will work.
http://s385.photobucket.com/albums/oo291/jim540/?action=view&current=VID_20120114_144121.mp4

 

[jim540]

Just an update on my carburetor conversion. It felt a little lean just off idle. If you applied throttle slowly sometimes it would die. Riding it the bike would hesitate a little on acceleration. Once you got through that little stumble it ran great. I figured it was in the pilot circuit so I ordered some more jets to make dialing in the carburetor a little easier. I was using a number 25 pilot jet, I ordered a 27.5 and a 30 so I could step it up one size at a time. I installed the 27.5 this morning and took it out to play with it. Started right up, I let it idle for a little while to get the engine warm. The engine doesn't have the little stumble any more and accelerates nicely. I 'll have to wait for warmer weather to give it a road test of any length but for now it is looking good. Temp outside when I was playing was about 43 degrees F.