Can anyone please provide BS38 slide specs ?

[peanut]

could someone please measure their late BS38 slides for me with a vernier guage .I need the exact dimensions of a late VM22/210 BS36 1978-1979 slide.....thats the later slide that takes the longer 502 jet needle and the Z2 needle jet combo.

I may actually have a pair of suitable slides in my parts box but I cannot tell without having the correct dimensions of a late slide to compare with

I have a pair of late BS38 78-79 carbs fitted with 2x unknown slides fitted with Z8 needle jet (76-77) and 4N8 needles (74-75) and 2x 25 pilot jets (model unknown ) without air holes ie non vm22/210 types. Its a Frankenstein Heinz 57 mess that someone sold me online and I bought on trust. .............

 

[650Skull]

post a photo of the your slides and i'm sure the experts will be able to identify your slide..................Slide diaphragms get brittle and shrink if they are not kept sealed in the carbs/something...............proberbly need new ones of those..................Might be cheaper to spend money on your EX500 carbs............i was waiting for your write up in the XS500 thread after you found out where to get the jets in England

 

[gggGary]

could someone please measure their late BS38 slides for me with a vernier guage .I need the exact dimensions of a late VM22/210 BS36 1978-1979 slide.....thats the later slide that takes the longer 502 jet needle and the Z2 needle jet combo.

I may actually have a pair of suitable slides in my parts box but I cannot tell without having the correct dimensions of a late slide to compare with

I have a pair of late BS38 78-79 carbs fitted with 2x unknown slides fitted with Z8 needle jet (76-77) and 4N8 needles (74-75) and 2x 25 pilot jets (model unknown ) without air holes ie non vm22/210 types. Its a Frankenstein Heinz 57 mess that someone sold me online and I bought on trust. .............

???? Can we assume they are BS38s?

 

[peanut]

ha ! you remembered the EX500 carbs ...
I was hoping to make this spare BS38 set, an easy bolt-on-solution
The EZ500 set are sitting there waiting to be built . but I have a 64 Lambretta LiS 150 to finish building first .

 

[peanut]

???? Can we assume they are BS38s?

yes they probably are because the slides have the typical VM22 cutaway but It doesn't help me because they are possibly early slides which won't accept 502 needles . When I have the measurements I can start looking for the correct slides.
They are available for as little as $200 but that is too expensive for me to take the risk in buying.

There are hundreds of sales all over the net that have the incorrect year/model/ fit information . There are even sellers stating that their slides will fit all carbs from 72 -83 XS650 !......

 

[650Skull]

Course i remember Peanut..................i had bought a set of carbs, posted in the EX500 thread and was in the process of doing a complete rework of the thread to condense the relevant information down from the 27 pages.

I removed my posts and any pics from that thread and didn't do the rework after you complained and argued about the availability and lack of information on suppliers for the jets and needles...........I removed my self from that thread because i didn't want to clutter up a good thread with stupid arguments.......Better to loose some info than have pages of crap

 

[gggGary]

Per 5twins this ain't the right slide for a 78-9
This slide was in a set of parts 78-79 carbs. I cannot guarantee it was always in these carbs.

Are these the only ones with the plastic button that holds the needle?

 

[5twins]

That appears to be a '77 or older slide. That type held the needle in the slide with only the return spring pushing down on the large plastic disc. It's a pretty simple set-up consisting of just 4 parts - needle, e-clip, retaining disc, and return spring .....

The '78-'79 slide was more complicated. It held the needle in with a snap ring on top of a sort of golf tee shaped plastic part. The needle itself had a couple spacers on it besides the e-clip and sat on a little spring .....

 

[gggGary]

let me know if you need more measurements.

 

[peanut]

Course i remember Peanut..................i had bought a set of carbs, posted in the EX500 thread and was in the process of doing a complete rework of the thread to condense the relevant information down from the 27 pages.

I removed my posts and any pics from that thread and didn't do the rework after you complained and argued about the availability and lack of information on suppliers for the jets and needles...........I removed my self from that thread because i didn't want to clutter up a good thread with stupid arguments.......Better to loose some info than have pages of crap

never mind all that crap skull lifes too short eh ?!
Me ?... I can barely remember what I ate for breakfast most days .

So what progress have you made on condensing this thread and working on your carbs .?

 

[5twins]

The external measurements on both slide types will probably be the same (or nearly so). After all, they can be swapped. I think the big differences will be on the inside, the inside depth and the machining down inside where the needle and snap ring fit. On the later slide, the hole the needle fits into will be much deeper. It has to hold the needle, 2 spacers, and a spring.

 

[peanut]

let me know if you need more measurements.
]

my guess is 36 24 36

thank you gary you're a real star matey.

 

[gggGary]

My guess is a foam bra.............

 

[peanut]

The external measurements on both slide types will probably be the same (or nearly so). After all, they can be swapped. I think the big differences will be on the inside, the inside depth and the machining down inside where the needle and snap ring fit. On the later slide, the hole the needle fits into will be much deeper. It has to hold the needle, 2 spacers, and a spring.

thank you 5T this slide business is a complete minefield. Without your research and experience I think it would be extremely difficult to fathom this unless you had an extensive box of bits , a vernier and a lot of patience

 

[5twins]

I never compared measurements between the 2 slide types, actually never even measured them. Too bad you didn't bring this up a few weeks ago. I had all those carbs out and was tinkering with them (butterfly plate screws). Eventually, I'll get around to it (pics, measurements). Honestly, you're the first person to bring this up that I can remember. Sure, there have been questions about the slide differences, but I've never seen an in-depth comparison with measurements.

Unfortunately, you can't scrounge the late '78-'79 slides from any other model, they were only used in the 650 carbs. Early slides can be scrounged (XS500, TX750).

 

[peanut]

My guess is a foam bra.............

no foam in those meaty thighs though !

Could I trouble you for a measurement inside the slide as 5T suggests and that should clinch it I reckon .

 

[peanut]

I never compared measurements between the 2 slide types, actually never even measured them. Too bad you didn't bring this up a few weeks ago. I had all those carbs out and was tinkering with them (butterfly plate screws). Eventually, I'll get around to it (pics, measurements). Honestly, you're the first person to bring this up that I can remember. Sure, there have been questions about the slide differences, but I've never seen an in-depth comparison with measurements.

Unfortunately, you can't scrounge the late '78-'79 slides from any other model, they were only used in the 650 carbs. Early slides can be scrounged (XS500, TX750).

so just to get this a bit clearer in my mind .

You can use any BS38 slide in a 78-79 VM22 carb set provided you use the original needle and fixing plate etc that matches that slide ...yes ?
presumably it would take a bit of rejetting and tuning as there is quite a lot of differences throughout the BS38 range but it could be made to work yes.

I can obtain a 502 needle and Z2 jet its the slide and the needle plate kit I'm struggling to source at the moment. The XS750 uses a very similar plastic top hat plate I was wondering if I could look for this needle fixing parts from another bike like Kawa or Suzy etc

 

[gggGary]

The measurement is from the top metal ring to the lowest point at the outside, the bottom is dished so it's lower in the middle

And now back to my regular entertainment

 

[5twins]

Yes, you can swap slides around as long as you use that slide with it's original needle (or one close to the same length) and match the other jetting to the needle. The 5O2 (5 series) needle used in the '78-'79 slide is a good 5 to 6mm longer than the 4M1 (4 series) and other needles used in the earlier slides. The reason for the change in needle length was because of the way they mount in the slide. The 5O2, with all it's extra spacers and little spring, sits much higher in the slide. It had to be longer to still hang out the bottom the same amount. That's the important "working" part of the needle, how much hangs out of the bottom of the slide. If you measure that on the 5O2 in the later slide and the 4M1 in the earlier slide, you'll see they are about the same (33 to 34mm).

 

[peanut]

Yes, you can swap slides around as long as you use that slide with it's original needle (or one close to the same length) and match the other jetting to the needle. The 5O2 (5 series) needle used in the '78-'79 slide is a good 5 to 6mm longer than the 4M1 (4 series) and other needles used in the earlier slides. The reason for the change in needle length was because of the way they mount in the slide. The 5O2, with all it's extra spacers and little spring, sits much higher in the slide. It had to be longer to still hang out the bottom the same amount. That's the important "working" part of the needle, how much hangs out of the bottom of the slide. If you measure that on the 5O2 in the later slide and the 4M1 in the earlier slide, you'll see they are about the same (33 to 34mm).

ok ...now its starting to make sense to me ....thanks
...what about needle width and profile to suit the Z2 needle jet ?.

I have found a source of 78-79 XS650 carb repair kits very cheap at about $25 for 2 complete kits !.The needles are Y267 I'm wondering if I should take a chance and buy them . The rest of the bits would make it worthwhile I should think. float jets and needles gaskets chokes & gaskets E clips O rings the lot . Everything except the needle jets