Capt Zoom see post #16. They also did a guide for the VM carbs. www.amckayltd.com/vm34-36.pdf
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34 carbs: wondering if I could get lucky.... thinking out loud
- Thread starter emzdogz
- Start date
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- carburetors
How are the o-rings? They are normally brittle with age, if the seat come out easily the o-ring is probably toast.
the o-rings are lovely. The only rubber that's looked dried out has been the caps that go over the pilot jets. They've shrunken a little. The seats didn't come out super-easy, but they weren't brutally hard to get out, either. Same with pins that hold floats.
Robbo
Robbo
Good luck emz I really hope it fires without further more difficult and time consuming work.. Cant hurt to at least try them with a mild cleaning...And go from there if things fail..
so here it is, over 2 months later.
After a couple of cleanings and just today replacement of air mixture screws (and o-rings of course) the bike starts up REALLY nice and idles pretty well.
One concern though is the pipes are discoloring differently. The pipes are powdercoated silver and the left pipe is turning brown looking at the lower bend. Not sure if maybe this is a flaw in the coating. Most pipes I've seen that discolor, do it most up by the head and around the first bend. So far no discoloration at heads.
I'm not worried about the color except as a possible indication of over-heating on that side.
But there's still lots to do! Still haven't done a valve and/or cam chain adjustment.
Before I swapped out the air mixture screws it was doing this thing where after applying throttle it wouldn't come back down to idle right away. It would hover at higher RPM. Now it comes right back down. Also switched the throttle cable and grip tho, so that may something to do with it.
Looks like I will be using the stock throttle housing for now, as I just can't spend any more $$, and the chopper one I'd bought won't work with stock XS cables.
So, now that I'm faced with using that throttle housing, I'm also thinking I'll try to make that starter button functional - and maybe kill switch, too.
Right now I have a big rubber momentary switch just kind of dangling below the coil and would have to figure out a place to put it, anyway. So I guess instead, I'll spend that energy trying to wire in the stock starter button, and save the other button for later.
It's getting REAL hot now already outside in my carport. I would just wait til November but dang tho! bike WANTS to run!!!!!! I can't believe how nice it sits there and idles now! and if I blip it, it comes back down to idle so nice.
Still need to maybe adjust the air mixture screws. I'm just not sure they are set equally. I know you're supposed to screw them in til they "seat lightly" and then turn out from there. But one persons' "seat lightly" may be another's "that's way too tight!"
anyway, just wanted to express my thrill at better running after swapping out those screws.
After a couple of cleanings and just today replacement of air mixture screws (and o-rings of course) the bike starts up REALLY nice and idles pretty well.
One concern though is the pipes are discoloring differently. The pipes are powdercoated silver and the left pipe is turning brown looking at the lower bend. Not sure if maybe this is a flaw in the coating. Most pipes I've seen that discolor, do it most up by the head and around the first bend. So far no discoloration at heads.
I'm not worried about the color except as a possible indication of over-heating on that side.
But there's still lots to do! Still haven't done a valve and/or cam chain adjustment.
Before I swapped out the air mixture screws it was doing this thing where after applying throttle it wouldn't come back down to idle right away. It would hover at higher RPM. Now it comes right back down. Also switched the throttle cable and grip tho, so that may something to do with it.
Looks like I will be using the stock throttle housing for now, as I just can't spend any more $$, and the chopper one I'd bought won't work with stock XS cables.
So, now that I'm faced with using that throttle housing, I'm also thinking I'll try to make that starter button functional - and maybe kill switch, too.
Right now I have a big rubber momentary switch just kind of dangling below the coil and would have to figure out a place to put it, anyway. So I guess instead, I'll spend that energy trying to wire in the stock starter button, and save the other button for later.
It's getting REAL hot now already outside in my carport. I would just wait til November but dang tho! bike WANTS to run!!!!!! I can't believe how nice it sits there and idles now! and if I blip it, it comes back down to idle so nice.
Still need to maybe adjust the air mixture screws. I'm just not sure they are set equally. I know you're supposed to screw them in til they "seat lightly" and then turn out from there. But one persons' "seat lightly" may be another's "that's way too tight!"
anyway, just wanted to express my thrill at better running after swapping out those screws.
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I think you mean air mix screws not enrichener screws. The enrichener is what most call a choke. No adjustment screws on them.
Leo
Leo
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Well, technically speaking, they are just mix or mixture screws, not "air mix". They control fuel flow (or more correctly, fuel/air mix flow) not air. Some carbs do use an air screw instead of a mix screw but none of the 650 CV carbs do. They all have true mixture screws. The way to tell which kind it is on about 99% of the carbs out there is to look at it's location. If the screw is located between the slide and the motor, it is a mixture screw, between the slide and the air filter then it is an air screw. The aftermarket VM carbs that many put on their 650s have an air screw.
