-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
best pod filter?
- Thread starter pahako
- Start date
-
- Tags
- carburetors
Probably an MJ fit. They slide on pretty easy and fit nice and snug. I actually feel it's a perfect fit. My buddy crammed them on his BS34s and that is not a good fit. I'm surprised the rubber flanges haven't split on him yet. He does strange things to his 650s (like setting his plastic floats to the brass float spec). Needless to say, that bike never ran right like that, lol.
IF room is not an issue witch would be a better uni. BTW this is for an xs400 and being attached to the stock cross-over. I would have asked this on the 400 forum but there is a lot more knowledge about this sort of stuff here
Attachments
Going to get the 6" since I have room to put them in.mndave
XS650 New Member
good info in this thread, I may have just been lucky that mike's pods were out of stock, as it seems the uni's are the way to go.
I have carb rebuild kits on the way, does anyone have a suggestion as to a starting point for re-jetting. [as in where to go from the stock jets]
78 xs 650
also, I dont have mufflers installed yet , I suspect that the lack of backpressure will affect the jet size?
I have carb rebuild kits on the way, does anyone have a suggestion as to a starting point for re-jetting. [as in where to go from the stock jets]
78 xs 650
also, I dont have mufflers installed yet , I suspect that the lack of backpressure will affect the jet size?
Interesting thread, although I replaced the CV carbs with RS34s.
Now, if I was to replace my current K&Ns with UNI pod filters,
I wonder if #UP-4229ST (Dual Layer, 4" OD, 4" Length)
will have sufficient flow capacity for a 750 with a Shell #1 cam, and a somewhat more open exhaust than standard? (Not straight pipes, just a bit louder mufflers)
Now, if I was to replace my current K&Ns with UNI pod filters,
I wonder if #UP-4229ST (Dual Layer, 4" OD, 4" Length)
will have sufficient flow capacity for a 750 with a Shell #1 cam, and a somewhat more open exhaust than standard? (Not straight pipes, just a bit louder mufflers)
SpoogeMCMM
XS650 Addict
Does anyone have an opinion, maybe 5twins, in advantages or disadvantages of the dual layer uni vs the regular ones?
I never tried the dual layer so I really can't say. If you like the look then go for it. They are the same filter as the single layer with just an extra red "sock" over the top. If you don't like them, you can simply remove the red second layer and be left with a normal single layer filter.
SpoogeMCMM
XS650 Addict
I like the "sock" it would match my red and black theme that i will eventually had, just didnt want to cause any restriction of airflow due to it.
mndave, You shouldn't buy carb kits, most don't have the parts you need.
Best to follow the steps in the carb guide to tear down, clean and inspect the parts. Then decide what needs to be replaced. Often you don't even need new gaskets.
Leo
Best to follow the steps in the carb guide to tear down, clean and inspect the parts. Then decide what needs to be replaced. Often you don't even need new gaskets.
Leo
cocinero196
XS650 Enthusiast
hi guys, after reading this thread, i'm still confused...i have a '76 xs650 w/ BS38's, everything is stock. If i were to remove the airbox and replace them w/ uni foam filters, which UNI model should I get? Some are saying to get the PK-92 53-55mm, some say get a 50mm Uni Pod so it's snug. Hope someone can point me to the right direction.
Btw, do i need to rejet after? considering everything else is stock. If yes, what needs to be changed?
TIA!
Btw, do i need to rejet after? considering everything else is stock. If yes, what needs to be changed?
TIA!
theDQG
XS650 Addict
Following
littlebill31
Smells of Raw Fuel
I prefer the UNI pods. For 38's you need the UP4200
And yes, you will have to re-jet after you remove the air boxes. Usually one up on the pilots and mains. HOWEVER!, everyones bike is different, so it's best to buy a couple different sizes and test the bike.
For the BS38s, you would want a 2" I.D. filter flange. That would be the PK-82 or the UP4200 (UP4200ST dual layer). I don't care so much for the PK-82 and PK-92 sets. They are shorter and have an end cap (see xschris pic #2 above). They only draw air in the sides. The UP4200 is an inch longer and foamed over the end. It draws air through the back and sides.
If you went with the PK-82 set, you may not need any re-jetting. We put a set on a local guy's '78 and didn't have to change any jets. This tells me those filters don't flow much, if any, more than stock. I'm not surprised since they're short and capped on the ends. If you went with the better flowing UP4200, you may need some minor re-jetting. Not much probably, just a size or two up on the mains. But only testing will show you for sure what you need.
What you have to realize about the '76-'77 carb set is that it came with very small mains from the factory, 122.5's. These were the smallest ever put in a 650. They work fine on an all stock set-up but are quickly out-paced when you start modding things. Whereas most of the other 650 carb sets can do with one or two sizes up on mains for minor mods, your set sometimes needs more. As an example, I dialed in a set for my '78. The stock '78 carbs were good with two up on the mains. This '76-'77 set required four up. This was for UNI pods and a freer flowing Commando exhaust. If the pods are your only mod, you probably won't need to go quite as big as I did.
If you went with the PK-82 set, you may not need any re-jetting. We put a set on a local guy's '78 and didn't have to change any jets. This tells me those filters don't flow much, if any, more than stock. I'm not surprised since they're short and capped on the ends. If you went with the better flowing UP4200, you may need some minor re-jetting. Not much probably, just a size or two up on the mains. But only testing will show you for sure what you need.
What you have to realize about the '76-'77 carb set is that it came with very small mains from the factory, 122.5's. These were the smallest ever put in a 650. They work fine on an all stock set-up but are quickly out-paced when you start modding things. Whereas most of the other 650 carb sets can do with one or two sizes up on mains for minor mods, your set sometimes needs more. As an example, I dialed in a set for my '78. The stock '78 carbs were good with two up on the mains. This '76-'77 set required four up. This was for UNI pods and a freer flowing Commando exhaust. If the pods are your only mod, you probably won't need to go quite as big as I did.
