Still running rough

[STVR]

Hello,

So I have a 1975 XS650 and I have been messing with carbs a little too much I think. I started out by changing my needle position not really sure why, I think I had tried everything else but that. So the clip is in the center where it used to be was 1 slot below the center. Now I have cleaned my carbs like 4 times cleaned everything. It was running better but when I put it in 1st and pull back on the throttle it sputters then dies and when it doesn't die it sounds pretty choppy.Perhaps its a fuel screw setting? I also put new plugs in yesterday and they are gapped right. Should I go back to the original clip setting? I also did my valve lashings about 2 months ago maybe I should recheck. I also have large capasity fuel filters on which are the wrong size they will work but there is a mild kink in the hose. Maybe I could put my old fuel filters on which are the right size but then I don't want to get any gunk in there from old fuel filters

 

[5twins]

The #4 slot is the stock needle setting for your carb set. It should work if other things (like the jet sizes) haven't been changed and the bike is still basically stock. Here's a chart I made up showing the stock settings and jetting for the 650 carbs. Check what's in yours against what should be. Also insure the floats are set to the correct level and that the mix screws are at or near the spec .....

 

[STVR]

how can I tell which size I currently have?

 

[5twins]

They have numbers stamped on them but you'll have to remove them to read them. The main jets are stamped on the top so you may be able to read them by just removing the drain bolt on the bowl bottom but all the others are stamped on the side. They'll need to come out.

 

[STVR]

Well I took apart the carbs...again and recleaned and I also went back to the stock setting on the needle per 5twins recommendation (thank you 5 twins) I also rechecked my valve clearences and they were a little off, put everything back together did the fuel screw 3/4 turn out and everything seems to be running fine just gotta get the timing down tomorrow. I get an occasional pop and sprayed carb cleaner near the pods (Mikes XS) and I seen to have a vacuum leak so I put some teflon tap around the carb and its better but not gone

 

[STVR]

Hey 5 Twins should I be using the Uni air pods instead of the Mikes XS ones? If so which ones should I use and where can I buy them?

 

[5twins]

Yes, if you want the best performance and easiest tuning , get the UNI pods. You would want the UP4200 or the UP4200ST (dual layer). These have a 2" I.D. mounting flange and will fit on your BS38s like a glove. Many places sell them, maybe even your local shop. This place doesn't list them by UNI part # but rather by size. You want the 2" x 4" .....

http://www.motorcycle-superstore.co...lter-Clamp-On-Pod-Filter.aspx?WT.ac=SLIsearch

Here's their web page with the pods .....

http://www.unifilter.com/clamp-on/

 

[STVR]

5 Twins I just wanted to say thank you. Whenever i have a question you always have an answer. You have a wealth of knowledge on these bikes and always happy to share what you have learned, your a great asset to this website. I bought those Uni filters, tuned everything up and my bike is running better than it ever has.....thanks again 5 Twins!