Leaky Carbs

[jposig]

1958 R/50. I've been riding this bike for well over 30 years after inheriting it from the original owner. Has always run great and start on the first or second kick.

I went to ride it one day, tickled it like I've always done, and fuel started leaking out of the side main jet and the 2 little vent holes in the carb body below the slide on the air box side.


Knowing everything was original, and at the recommendation of members here, I sent them to Charlie/BING. He went through them completely and replaced/upgraded all of the parts. I installed the
carbs and they still leaked with my usual tickling method.

I called Charlie and he said send them back, which I did. He took me on right away, reset the float heights, bench tested and sent them back to me. Installed carbs, same thing, called him and he said he has no clue.

While he had the carbs the first time, I drained the tank which is still super clean from the factory sealant in it, and replaced the petcock assembly with a factory unit. When I got the carbs back, I installed my usual 93 non ethanol fuel.

I'm going to call Charlie again, but curious if anyone here has had this issue and what the fix is. Though totally different animals, 3 seconds is the time to tickle the carbs on my Norton.
For the helluva it, it took 10.5 seconds for fuel to come out the tickler on the left side carb, and 13.6 seconds for fuel to come out of the right side carb.

I'm now wondering if my issue is being caused by keeping the ticklers down too long after the rebuild and with the new and upgraded parts.

Any input greatly appreciated.

Thank you,
Jim

[20774]

Jim -

Are you saying you're holding the ticklers down over 10 seconds on each carb and they finally flooded? I would expected much sooner, but there is no reason to hold them down that long...hopefully you were just doing a test. I agree with the Norton scheme, maybe 2-3 seconds at most.

The tickling/starting technique is something that each owner has to figure out with their machine...they seem to have a mind of their own! After 30 years, I suspect you know it well. When cold, I also do the 2-3 seconds tickle, then with throttle closed, kick the engine over maybe 5-6 times. Then I crack open the throttle a small amount, bring the kick start around to the beginning of a compression stroke, and then push it firmly through. Usually starts right up.

With the work that Bing has done, the carbs should be good. If the floats are working, once you let up on the tickler, the fuel flow should stop. If they aren't, could be some dirt is on the seat. But you cleaned the tank. On my R69S, I have two clear plastic filters on the lines to each carb as a check against grit.

Let us know what Charlie says.

[kbasa]

1958 R/50. I've been riding this bike for well over 30 years after inheriting it from the original owner. Has always run great and start on the first or second kick.

I went to ride it one day, tickled it like I've always done, and fuel started leaking out of the side main jet and the 2 little vent holes in the carb body below the slide on the air box side.


Knowing everything was original, and at the recommendation of members here, I sent them to Charlie/BING. He went through them completely and replaced/upgraded all of the parts. I installed the
carbs and they still leaked with my usual tickling method.

I called Charlie and he said send them back, which I did. He took me on right away, reset the float heights, bench tested and sent them back to me. Installed carbs, same thing, called him and he said he has no clue.

While he had the carbs the first time, I drained the tank which is still super clean from the factory sealant in it, and replaced the petcock assembly with a factory unit. When I got the carbs back, I installed my usual 93 non ethanol fuel.

I'm going to call Charlie again, but curious if anyone here has had this issue and what the fix is. Though totally different animals, 3 seconds is the time to tickle the carbs on my Norton.
For the helluva it, it took 10.5 seconds for fuel to come out the tickler on the left side carb, and 13.6 seconds for fuel to come out of the right side carb.

I'm now wondering if my issue is being caused by keeping the ticklers down too long after the rebuild and with the new and upgraded parts.

Any input greatly appreciated.

Thank you,
Jim

On my R60, I just push them down a couple times for about a second each until fuel dribbles out of the tickler. I generally don't use any choke at all, and it starts right up.

[20774]

IMO fuel coming out of the ticklers is way too much. I think this might be a hold over from some very old motorcycles. The idea is to fill the float bowl back to normal values or so. Then by kicking with the throttle closed, you pull gas fumes into the combustion chamber. Once that's done, that mixture should light off provided the bike's in good tune. If you tickle too much, there is the danger that fuel will flow through the carb throat into the intake valve and create hydro lock in the cylinder...that can bend a conrod. They don't need to be "flooded"!

[jposig]

IMO fuel coming out of the ticklers is way too much. I think this might be a hold over from some very old motorcycles. The idea is to fill the float bowl back to normal values or so. Then by kicking with the throttle closed, you pull gas fumes into the combustion chamber. Once that's done, that mixture should light off provided the bike's in good tune. If you tickle too much, there is the danger that fuel will flow through the carb throat into the intake valve and create hydro lock in the cylinder...that can bend a conrod. They don't need to be "flooded"!

I totally agree with you about "old school" thinking in everything, and I've been riding and racing bikes since the late '60's. Just because my method worked for 30 years doesn't mean that I shouldn't modify my methods now especially with all of the new updated parts in the carbs.

I just spoke with Charlie and explained everything as I had put in my thread here. He said he has the same bike/carbs as I do and stated he barely touches the ticklers at all. There really isn't a generally accepted spec on these carbs like there is with the Norton rule.

I know that each individual bike regardless of marque' has a unique starting technique that the rider needs to develop, and that's what I'm. going to do now.

I'm draining the oil and will kick it over a lot to attempt to get as much of the fuel out of the motor as possible while draining and clearing the carbs which have been sitting for days. Then I'll install fresh oil and plugs and start with 1 second tickling, try to start, then 2 seconds, try to start, etc....

Will post results when I've got it running again.

Many thanks to all of you for your time with responses.

Jim

[kbasa]

I give each of mine a pair of like one second pokes. A little fuel comes out of the left one, none on the right. I'll kick it through lightly to get to TDC, then give it a decent kick. Sometimes, first kick, usually second kick and it starts.

[20774]

Neither of my carbs leak after tickling...I usually push them for a count of 2 or 3. Bikes starts pretty quickly. I still contend that physical leaking of the carbs when tickling is not correct. Vech's procedure for starting was "NO TICKLING". Petcocks on for a count of 5, then off. No tickling, no throttle. Kick start the bike. Then petcock open, light throttle. My bike never started that way!! Guess there's various ways of starting them. YMMV!