Misfiring Is Weird?

[miketx750]

so you didn't plug the holes in the sides of the carbs and just left them in the cracked and corroded condition? ok, guess that works for me. sounds like they are not contributing to my problem anyway so i'lll just leave mine there. thanks.

[arcangel]

Don't you have a vacum leak with the tubes missing and would't this be a great place for water dirt and other things to get in the carb and block it up? Ya I know alot of questions

[miketx750]

That makes sense, too, arcangel. I'm waiting for reply from Silex88 regarding my last post. However, I think these breather systems are just that, they equalize air pressure in the carbs, but they don't go into the vacuum system at all. So if a guy left the breather parts off, he would probably want to seal the openings, just to keep goop out. But I'm gonna wait on this for a while. Thanks for the heads up. Mike

[Silex88]

I wouldn't recommend sealing the holes. I know you can leave them open, but sealing them might cause some issues. I figured I would rather leave a damaged T on there than let the goop get in from wherever. Thus, I agree that it wouldn't be the BEST idea to leave them just freely open, but it can be done.

[miketx750]

There's the answer: leave the breather parts on, whether they are in good condition or not, as they will prevent nasties from getting in. Thanks guys for the help. I'm outa this thread, but the originator, Harvest Fields, hasn't been heard from in a while. I suspect he's out too so we can put this one to bed.

[old gringo]

DO NOT seal the openings (ask me how I know ). If you do, gas will pour out of the carb throats due to some type of suction effect when the slides move up & down. The vents are there to relieve this. Also, use a small piece of vacuum hose to connect #2&#3. Don't really know why, but do it anyway.

[miketx750]

My 2 & 3 are connected with vac hose already. And I WON'T seal those openings. Thanks for the tip.

[arcangel]

I have said this or asked this before .
But Isn't there a likely hood of water and trash being sucked in the carb and the breather from the open holes, also Would it cause a vacum leak?

[miketx750]

Sorry we didn't answer that. My understanding is that there is no strong vacuum created through those ports and hoses. Apparently the movement of the throttle slides causes some pressure differentials that need to be equalized. The low pressure that occurs when the slides move up (see Ol Gringo's remarks) probably would not cause enough sucking action to bring in dirt and stuff at those ports. But remember, we are cautioned NOT to seal off those ports but to leave the T-fittings and hoses on, even if the system doesn't work quite right. That would prevent dirt from getting in.

[Silex88]

You are exactly right sir.

[miketx750]

Gosh Silex, if I'm right that would be the first time in...well, maybe 71 years!

[arcangel]

That is my under standing as well.

I still believe in the rain the water from the road could get thrown up in to the carbs if the openings were open to the road, too much water splashes up from the road at least ,my bike seems to get a lot of dirt and water spots up under the carb area in the rain.

Well I for one don't have to worry about that I took the reaming and bout the t'S

[Rgus]

@ Harvest Fields, I know this is an old post but I have the exact same problem.

You wrote: "Ok. Simple problem. The bike starts and idles fine but if you hold the throttle open at say, 4-5000 rpm it has a popping ( backfire? ) this is only coming from cyl 3 and 4. put your hand over the exhaust on 1 and 2 and its fine. on 3 and 4 you can feel it popping."

Do you, or anyone else have a remedy or suggestion for this?

[GeorgeSweety]

Hi Rgus, my first suggestion would be to check your spark plugs to see if there is an obvious difference between plugs 1+2 and 3+4, which might indicate that your air/fuel mixture might need adjusting on carbs 3+4. I would suggest new spark plugs, caps and leads, relatively cheap and easy to do, if you still have the same problem at least you will have eliminated that side of things.
What type of carbs have you got on your bike? Have you inspected your carb inlet rubbers for cracks? Have you cleaned your carbs? Do you still have the fuel shut off connected?, have you checked your vac hoses for leaks?