Lewi TX650 Bike Updates!

[TwinLewi]

Hey guys and gals,
Just getting online to toss out some information and photo’s of my old girl. Last time on I was seeking a lot of help for front brake issues! Thanks to all for the help! Caliper was rebuilt, new lines installed and rebuilt the M/C! New pads as well! Since then I have Rebuilt the forks and replaced the rear shocks with some Koni shocks formally know as Ikon Suspension! New head lamp conversion kit to have a H4 bulb! Purchased new Carbies from Mikuni!! VM34’s in hopes to eliminate flat spits, get some more power, and have a littler newer set up. Don’t like the POD filters however. Keeping my old carbs so don’t even ask if you can buy them. Running well except I am fowling plugs like no ones business. Was fowling plugs before carb replacement! Having some charge issues all a sudden to. Battery is reading fine but dose is having issues after a few days of not running. It was replaced a couple months ago. Anyways having fun, always learning and wrenching. One day she will be tip top! Enjoy the ride and the knee’s in the breeze!

 

[5twins]

You may need bigger air filters, those look kinda small (too restrictive). Pull them off and take a test ride, see if the plug color is better. I think the usual choice for the VMs is the RU-0600 (4" long) or the RU-0610 (5" long). Both of those are also straight, not tapered.

 

[TwinLewi]

You may need bigger air filters, those look kinda small (too restrictive). Pull them off and take a test ride, see if the plug color is better. I think the usual choice for the VMs is the RU-0600 (4" long) or the RU-0610 (5" long). Both of those are also straight, not tapered.

Yea I would agree with ya. I have uni filters that fit my stock carbs. 100mm length foam style with the spring inside em. Those seemed to work well. Except I was failing plugs with those. Tom at Mikuni Oz send out the carbs spec’d out for the xs650. Running a 220 main jet. Not sure what the pilot jets are or any others at this point in time. Clip on the needle is at setting two. It ran Alright with the 220 main but lost the power at top speed. Sputter’d. Put a 210 and it was better.
Geoff’sXS Xs said I need to change it completely. Run a 170 main jet, 25 pilot,
P5 needle, 6f9 needle jet, and use clip two position on the needle.

 

[TwinLewi]

Not sure what keeps fowling me plugs.
When installing my new carbies I was doing some short test rides to get the main jets set right and on the second test I had low battery. To the point my bike wouldn’t turn over. Checked the battery and it was at 12.4V. So I charged it up and slapped it back in the bike and it idled at 12.6V. I revved the bike up and could get it to 13.4. That should indicate a good alternator. I need to test that still but yea that should be fine. I keep putting new plugs in and keep fowling them. Need to sort out my charge system. Need to figure out what is failing plugs. Air mix screw is 1.75 turns out. Idle is 5.5 turns out. Any help would be rad.
‍

 

[gggGary]

I'm with GEoff's, madness is at 180s now and If I wasn't lazy would prolly have 175's
As setup by 650 Central, MM
Carb: VM34
MJ: 180 I had wandered quite far up from here then ended up back down to the 180s when longer mufflers went back on. running mostly about 1,000' AMSL
PJ: 25
NJ: 159-P6
JN: 6F9, 3rd slot
Slide: 2.5
Air jet: ?
Float valve 3.3
Big UNI foam filters

 

[TwinLewi]

I'm with GEoff's, madness is at 180s now and If I wasn't lazy would prolly have 175's
As setup by 650 Central, MM
Carb: VM34
MJ: 180 I had wandered quite far up from here then ended up back down to the 180s when longer mufflers went back on. running mostly about 1,000' AMSL
PJ: 25
NJ: 159-P6
JN: 6F9, 3rd slot
Slide: 2.5
Air jet: ?
Float valve 3.3
Big UNI foam filters

That does not sound like a bad set up at all. I have stock headers and Muffler’s I am 99.9% sure. Muffs are pretty long. I am sorry but what is 1,000 AMSL? Lol

 

[gggGary]

Sorry; at an altitude of 300 meters Above Mean, (average) Sea Level,

 

[TwinLewi]

Awesome! You learned me!

 

[gggGary]

Nah I was sneaking in an aviation term
Thumbnailing but 170-180ish mains should work quite a bit better for you. YMMV
Your mileage may vary. Literally in this case.
Ole Madness is pretty hotted up but in general an XS650 should be getting near 50 MPG in typical riding.

 

[grizld1]

Welcome, Lewi! +1 re. Geoff's recommendations, he's a solid pro, but I'd want to have 22.5 pilots and 175 mains on hand as well. There's a threaded port for a small main air jet in the back of the carburetor. For street tuned motors things work best if that jet is removed, just run with the hole open. For dial in help, click the Tech button at the top of the screen, find the link to the VM section of the old XS650 Garage USA Carb Guide, and print it off.