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New carb kit and still leaky carbs....any suggestions?
- schrader7032
- Posts: 9038
- Joined: Fri Oct 27, 2006 3:00 am
- Location: San Antonio, TX
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New carb kit and still leaky carbs....any suggestions?
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
Not sure exactly where leak is coming from...
Different question - I was able to take this newly acquired bike out for a spin yesterday but the bike labored to get over 45 MPH. Any ideas on what the top end would be for an R60? It would seem that either the carbs are severely out of tune, or I'm a fat ass and weighing the bike down (220 lbs). How will it ever pull me and a sidecar for my dog????? thanks for advice and help
- Darryl.Richman
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New carb kit and still leaky carbs....any suggestions?
Most likely one or both of your carbs isn't sealing well against incoming gas. This could be because of a sunk float, or because the seal isn't in good condition.
If a float is sunk, you should be able to shake it and hear and feel the gas inside the float. New floats are available.
The latter situation varies according to the type of carb you have. If you have the original style carb tops, the fuel line barb is in the middle of the top, and the float seals the intake directly with the pin that runs through it. If you have the newer, lever-top style carbs, the fuel line barb is off to one side, and the float operates a lever and a small sealing tip.
With the original style tops, you can possibly use some valve lapping compound on the tip to make it conform (again) to the sealing surface in the top. The compound has to be thoroughly cleaned up after you're through.
With the lever top style, the sealing tip is a bit of steel with a rubber tip. The piece can be replaced.
Just took them apart again...
Also, I wipe the external tops clean with a rag, and within a few minutes of having the gas line open, they seem to have the moisture of gas on them, almost like the float chambers are so full that they are leaking out around the top.
Would excessive gas make it pop and skip when the accelerator is twisted? It idles like a champ, starts first kick, but when I apply the accelerator, it pops like it is choking. Are new tops for the float chamber still available, or will I have to try and use the lapping compound? thanks for all your help
- Darryl.Richman
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New carb kit and still leaky carbs....any suggestions?
Regarding your floats, float chambers and the covers: you should make sure that the chambers are clean and that the floats can easily move up and down in them. Probably they're ok, but a float might hang up on some corrosion.
To get an idea of whether your float seals off the top, you can remove the top and float from the carb, but leave the gas line connected to the top and the petcock. Holding it over a can or a bowl, open the petcock and see that the gas is flowing through the top, then lightly push the needle into the opening. It should seal with a very light pressure, when you hold it in line vertically with the top. If it doesn't seal, or requires more than a light touch, you should try lapping the needle into the seat.
Get a tube of valve lapping compound at an auto parts store. Remove the float chamber top from the bike and place it upside down in the jaws of a vise. DON'T TIGHTEN THE VISE -- just close the jaws enough to keep the top from rocking or turning. Put a dab of lapping compound on the tip of the float needle, and place it into the seat in the top. Hold the needle from the bottom, try to keep it vertical, and spin it back and forth a few times. Wash the needle and the top thoroughly before trying the test again or installing them back on the bike.
If you can't make the seat seal, you can buy new needles and new lever top style tops from Bing Agency in KS. I think we have a link to them in the resources area on the main part of the web site, or google them.
Good luck!
New carb kit and still leaky carbs....any suggestions?
Peter
Choke slide?
I tried the idea of using the valve grinding compound. It doesn't seem to have worked either, as I have a fresh pool of gas on the ground this morning. I think I'm going to call Bing and price out new float covers. Thanks for the help
- Darryl.Richman
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New carb kit and still leaky carbs....any suggestions?
The earlier R60 and R50 bikes had a shorter, rounder airfilter that is split across the middle. The air intake is part of the bottom half, and it incorporates a handle for closing a slide across the intake openings. (This is ususally very stiff to operate.)
If the choke is closed, it will enriched the mixture by limiting how much air can be drawn into the cylinders.
The ticklers also enrichen the mixture, temporarily, by holding the float down and allowing raw gas to flow into the carb throat.
Most /2 bikes need a tickling to get started when cold, but the manual recommends using the choke only when it's below freezing outside. I've never had the opportunity, nor felt the need, to use the choke on my R60.
Anyway, it sounds like you do need new tops and/or new float needles. But when you get new "lever top" tops, you won't need to replace the needles because the new design doesn't seal with the float needle.
This happened to me as well...
So I read some things on this site (which is why I signed up... to hopefully help someone else!) and I took them back apart.
The critical thing I was missing was the little "spacer." There is a little metal spacer (looks like a slightly thick metal washer, but is small diameter) that goes on the float slide... I guess that is what it is called..
Anyway, after doing some testing and messing around, I determined that my issue was that the float wasn't floating very well, because I had it upside down, and it tended to stick, and the washer was needed to help the upwards floating float seal off the incoming fuel.
Now both carb don't leak at all, and I am a happy camper.
-Dan